"Expecting Better gives moms-to-be a big helping of peace of mind! Oster debunks many tired old myths and shines a light on issues that really matter."Harvey, Karp, MD, bestselling author of The Happiest Baby Guide to Sleep and The Happiest Baby on the Block"It took someone as smart as Emily Oster to make it all this simple. She cuts through the thicket of anxiety and received wisdom, and gives us the facts. Expecting Better is both enlightening and calming. It almost makes me want to get pregnant."Pamela Druckerman, New York Times bestselling author of Bringing Up Bb and Bb Day by Day"This is a fascinatingand reassuringlook at the most important numbers of your pregnancy. It will make parents-to-be rethink much of the conventional wisdom: think bed rest is a good idea? Think again. This may be the most important book about pregnancy you read."Steven D. Levitt, New York Times bestselling co-author of Freakonomics "Expecting Better is a fascinating and reassuring tour of pregnancy and childbirth, with data leading the way at every juncture. From start to finish, Oster easily leads us through the key findings of the extant pregnancy-related research. My only regret is that my wife and I had three children without the benefit of this insightful approach."Charles Wheelan, New York Times bestselling author of Naked Statistics"The only antidote to pregnancy anxiety is facts, and Emily Oster has them in spades. Disarmingly personal and easy to read, this book is guaranteed to cut your freaking out in half. Pregnancy studies has a new heroine. Every pregnant woman will cheer this bookand want to take Oster out for a shot of espresso."Rachel Simmons, New York Times bestselling author of Curse of the Good GirlAbout the AuthorEmily Oster, the daughter of two economists and the wife of a third, is an associate professor of economics at the University of Chicago Booth School. She lives with her husband and daughter in Chicago.Excerpt. Reprinted by permission. All rights reserved. AcknowledgmentsThank you, first, to my wonderful book team. My agent, Suzanne Gluck, without whom this project definitely would not have gotten past chapter 1 and who tells me straight up when its not quite there yet. Ginny Smith is some kind of secret genius editor who got this turned into a real book when I wasnt even looking. Thanks to her, Ann Godoff, and the whole team at Penguin for enormous support, genius title creation, and all sorts of other things.Huge thank you to Jenna Robins, who read everything first, rewrote most of it, made me sound like less of an economist, and without whose help I never would have gotten off the ground.Emily L. Seet, MD, was an incredible medical editor (although any mistakes remain very much my own). Emily Carmichael created lovely graphs with little guidance. Jen Taylor provided invaluable contracting assistance.I am grateful to all my ladies, most of whom helpfully got pregnant at the same time and shared their stories (sometimes without knowing theyd be book fodder): Yael Aufgang, Jenny Farver, Hilary Friedman, Aude Gabory, Dwyer Gunn, Katie Kinzler, Claire Marmion, Divya Mathur, and, most especially, Jane Risen, Heather Caruso, Elena Zinchenko, and Tricia Patrick.Many colleagues and friends supported the idea and reality of this book at various stages. Including but by no means limited to: Judy Chevalier, John Friedman, Matt Gentzkow, Steve Levitt, Andras Ladanyi, Emir Kamenica, Matt Notowidigdo, Dave Nussbaum, Melina Stock, Andrei Shleifer, Nancy Zimmerman, and the More Dudes.Actually putting the time into writing this would not have been possible without the help of many, many people in running my household. Most important of all, Mardele Castel, who has been Penelopes Madu since day one, who makes Penelope happy and her parents relaxed, and who, very simply, makes it all work.Im lucky to have an incredibly supportive family. Thank you to the Shapiros: Joyce, Arvin, and Emily. To the Fairs and Osters: Steve, Rebecca, John, and Andrea. And to my parents: I couldnt ask for better ones; Penelope is lucky to have you as her mormor and Grandpa Ray. Mom, I hope you feel the ninety-six hours of labor was worth it.Finally, thank you to Jesse and Penelope, who, it goes without saying, were essential. You two make me happy every day. Penelope, you have the absolute best dad. I love you.IntroductionIn the fall of 2009 my husband, Jesse, and I decided to have a baby. We were both economics professors at the University of Chicago. Wed been together since my junior year of college, and married almost five years. Jesse was close to getting tenure, and my work was going pretty well. My thirtieth birthday was around the corner.Wed always talked about having a family, and the discussion got steadily more serious. One morning in October we took a long run together and, finally, decided we were ready. Or, at the very least, we probably were not going to get any more ready. It took a bit of time, but about eighteen months later our daughter, Penelope, arrived.Id always worried that being pregnant would affect my workpeople tell all kinds of stories about pregnancy brain, and missing weeks (or months!) of work for morning sickness. As it happens, I was lucky and it didnt seem to make much difference (actually having the baby was another story).But what I didnt expect at all is how much I would put the tools of my job as an economist to use during my pregnancy. This may seem odd. Despite the occasional use of Dr. in front of my name, I am not, in fact, a real doctor, let alone an obstetrician. If you have a traditional view of economics, youre probably thinking of Ben Bernanke making Fed policy, or the guys creating financial derivatives at Goldman Sachs. You would not go to Alan Greenspan for pregnancy advice.But here is the thing: the tools of economics turn out to be enormously useful in evaluating the quality of information in any situation. Economists core decision-making principles are applicable everywhere. Everywhere. And that includes the womb.When I got pregnant, I pretty quickly learned that there is a lot of information out there about pregnancy, and a lot of recommendations. But neither the information nor the recommendations were all good. The information was of varying quality, and the recommendations were often contradictory and occasionally infuriating. In the end, in an effort to get to the good informationto really figure out the truthand to make the right decisions, I tackled the problem as I would any other, with economics.At the University of Chicago I teach introductory microeconomics to first-year MBA students. My students would probably tell you the point of the class is to torture them with calculus. In fact, I have a slightly more lofty goal. I want to teach them decision making. Ultimately, this is what microeconomics is: decision sciencea way to structure your thinking so you make good choices.I try to teach them that making good decisionsin business, and in liferequires two things. First, they need all the information about the decisionthey need the right data. Second, they need to think about the right way to weigh the pluses and minuses of the decision (in class we call this costs and benefits) for them personally. The key is that even with the same data, this second partthis weighing of the pluses and minusesmay result in different decisions for different people. Individuals may value the same thing differently.For my students, the applications they care about most are business-related. They want to answer questions like, should I buy this company or not? I tell them to start with the numbers: How much money does this company make? How much do you expect it to make in the future? This is the data, the information part of the decision.Once they know that, they can weigh the pluses and minuses. Here is where they sometimes get tripped up. The plus of buying is, of course, the profits that theyll make. The minus is that they have to give up the option to buy something else. Maybe a better company. In the end, the decision rests on evaluating these pluses and minuses for them personally. They have to figure out what else they could do with the money. Making this decision correctly requires thinking hard about the alternative, and thats not going to be the same for everyone.Of course, most of us dont spend a lot of time purchasing companies. (To be fair, Im not sure this is always what my students use my class for, eitherI recently got an e-mail from a student saying that what he learned from my class was that he should stop drinking his beer if he wasnt enjoying it. This actually is a good application of the principle of sunk costs, if not the primary focus of class.) But the concept of good decision making goes far beyond business.In fact, once you internalize economic decision making, it comes up everywhere.When Jesse and I decided we should have a baby, I convinced him that we had to move out of our third-floor walk-up. Too many steps with a stroller, I declared. He agreed, as long as I was willing to do the house shopping.I got around to it sometime in February, in Chicago, and I trekked in the snow to fifteen or sixteen seemingly identical houses. When I finally found one that I liked (slightly) more than the others, the fun started. We had to make a decision about how much to offer for it.As I teach my students, we started with the data: we tried to figure out how much this particular house was worth in the market. This wasnt too difficult. The house had last sold in 2007, and we found the price listed online. All we had to do was figure out how much prices had changed in the last two years. We were right in the middle of a housing crisishard to miss, especially for an economistso we knew prices had gone down. But by how much?If we wanted to know about price changes in Chicago overall we could have used something called the Case-Shiller index, a common measure of housing prices. But this was for the whole citynot just for our neighborhood. Could we do better? I found an online housing resource (Zillow.com) that provided simple graphs showing the changes in housing prices by neighborhood in Chicago. All we had to do was take the old price, figure out the expected change, and come up with our new price.This was the data side of the decision. But we werent done. To make the right decision we still needed the pluses and minuses part. We needed to think about how much we liked this house relative to other houses. What we had figured out was the market price for the housewhat we thought other people would want to pay, on average. But if we thought this house was really special, really perfect, and ideal for us in particular, we would probably want to bid more than we thought it was worth in the marketwed be willing to pay something extra because our feelings about this house were so strong.There wasnt any data to tell us about this second part of the decision; we just had to think about it. In the end, we thought that, for us, this house seemed pretty similar to all the other ones. We bid the price we thought was correct for the house, and we didnt get it. (Maybe it was the pricing memo we sent with our bid? Hard to say.) In the end, we bought another house we liked just as much.But this was just our personal situation. A few months later one of our friends fell in love with one particular house. He thought this house was a one-of-a-kind option, perfect for him and his family. When it came down to it, he paid a bit more than the data might have suggested. Its easy to see why thats also the right decision, once you use the right decision processthe economists decision process.Ultimately, as I tell my students, this isnt just one way to make decisions. It is the correct way.So, naturally, when I did get pregnant I thought this was how pregnancy decision making would work, too. Take something like amniocentesis. I thought my doctor would start by outlining a framework for making this decisionpluses and minuses. Shed tell me the plus of this test is you can get a lot of information about the baby; the minus is that there is a risk of miscarriage. Shed give me the data I needed. Shed tell me how much extra information Id get, and shed tell me the exact risk of miscarriage. Shed then sit back, Jesse and I would discuss it, and wed come to a decision that worked for us.This is not what it was like at all.In reality, pregnancy medical care seemed to be one long list of rules. In fact, being pregnant was a lot like being a child again. There was always someone telling you what to do. It started right away. You can have only two cups of coffee a day. I wondered whywhat were the minuses (I knew the plusesI love coffee!)? What did the numbers say about how risky this was? This wasnt discussed anywhere.And then we got to prenatal testing. The guidelines say you should have an amniocentesis only if you are over thirty-five. Why is that? Well, those are the rules. Surely that differs for different people? Nope, apparently not (at least according to my doctor).Pregnancy seemed to be treated as a one-size-fits-all affair. The way I was used to making decisionsthinking about my personal preferences, combined with the datawas barely used at all. This was frustrating enough. Making it worse, the recommendations I read in books or heard from friends often contradicted what I heard from my doctor.Pregnancy seemed to be a world of arbitrary rules. It was as if when we were shopping for houses, our realtor announced that people without kids do not like backyards, and therefore she would not be showing us any houses with backyards. Worse, it was as if when we told her that we actually do like backyards she said, No, you dont, this is the rule. Youd fire your real estate agent on the spot if she did this. Yet this is how pregnancy often seemed to work.This wasnt universal, of course; there were occasional decisions to which I was supposed to contribute. But even these seemed cursory. When it came time to think about the epidural, I decided not to have one. This wasnt an especially common choice, and the doctor told me something like, Okay, well, youll probably get one anyway. I had the appearance of decision-making authority, but apparently not the reality.I dont think this is limited to pregnancyother interactions with the medical system often seem to be the same way. The recognition that patient preferences might differ, which might play an important role in deciding on treatment, is at least sometimes ignored. At some point I found myself reading Jerome Groopman and Pamela Hartzbands book, Your Medical Mind: How to Decide What Is Right for You, and nodding along with many of their stories about people in other settingsprostate cancer, for examplewho should have had a more active role in deciding which particular treatment was right for them.But, like most healthy young women, pregnancy was my first sustained interaction with the medical system. It was getting pretty frustrating. Adding to the stress of the rules was the fear of what might go wrong if I did not follow them. Of course, I had no way of knowing how nervous I should be.I wanted a doctor who was trained in decision making. In fact, this isnt really done much in medical schools. Appropriately, medical school tends to focus much more on the mechanics of being a doctor. Youll be glad for that, as I was, when someone actually has to get the baby out of you. But it doesnt leave much time for decision theory.It became clear quickly that Id have to come up with my own frameworkto structure the decisions on my own. That didnt seem so hard, at least in principle. But when it came to actually doing it, I simply couldnt find an easy way to get the numbersthe datato make these decisions.I thought my questions were fairly simple. Consider alcohol. I figured out the way to think about the decisionthere might be some decrease in child IQ from drinking in pregnancy (the minus), but Id enjoy a glass of wine occasionally (the plus). The truth was that the plus here is small, and if there was any demonstrated impact of occasional drinking on IQ, Id abstain. But I did need the number: would having an occasional glass of wine impact my childs IQ at all? If not, there was no reason not to have one.Or in prenatal testing. The minus seemed to be the risk of miscarriage. The plus was information about the health of my baby. But what was the actual miscarriage risk? And how much information did these tests really provide relative to other, less risky, options?The numbers were not forthcoming. I asked my doctor about drinking. She said that one or two drinks a week was probably fine. Probably fine is not a number. The books were the same way. They didnt always say the same thing, or agree with my doctor, but they tended to provide vague reassurances (prenatal testing is very safe) or blanket bans (no amount of alcohol has been proven safe). Again, not numbers.I tried going a little closer to the source, reading the official recommendation from the American Congress of Obstetricians and Gynecologists. Interestingly, these recommendations were often different from what my doctor saidthey seemed to be evolving faster with the current medical literature than actual practice was. But they still didnt provide numbers.To get to the data, I had to get into the papers that the recommendations were based on. In some cases, this wasnt too hard. When it came time to think about whether or not to get an epidural, I was able to use data from randomized trialsthe gold standard evidence in scienceto figure out the risks and benefits.In other cases, it was a lot more complicated. And several timeswith alcohol and coffee, certainly, but also things like weight gainI came to disagree somewhat with the official recommendations. This is where another part of my training as an economist came in: I knew enough to read the data correctly.A few years ago, my husband wrote a paper on the impact of television on childrens test scores. The American Academy of Pediatrics says there should be no television for children under two years of age. They base this recommendation on evidence provided by public health researchers (the same kinds of people who provide evidence about behavior during pregnancy). Those researchers have shown time and again that children who watch a lot of TV before the age of two tend to perform worse in school.This research is constantly being written up in places like the New York Times Science section under headlines like SPONGEBOB THREAT TO CHILDREN, RESEARCHERS ARGUE. But Jesse was skeptical, and you should be, too. It is not so easy to isolate a simple cause-and-effect relationship in a case like this.Imagine that I told you there are two families. In one family the one-year-old watches four hours of television per day, and in the other the one-year-old watches none. Now I want you to tell me whether you think these families are similar. You probably dont think so, and youd be right.On average, the kinds of parents who forbid television tend to have more education, be older, read more books, and on and on. So is it really the television that matters? Or is it all these other differences?This is the difference between correlation and causation. Television and test scores are correlated, there is no question. This means that when you see a child who watches a lot of TV, on average you expect him to have lower test scores. But that is not causation.The claim that SpongeBob makes your child dumber is a causal claim. If you do X, Y will happen. To prove that, youd have to show that if you forced the children in the no-TV households to watch SpongeBob and changed nothing else about their lives, they would do worse in school. But that is awfully hard to conclude based on comparing kids who watch TV to those who do not.In the end, Jesse (and his coauthor, Matt) designed a clever experiment.1 They noted that when television was first getting popular in the 1940s and 1950s, it arrived in some parts of the country earlier than others. They identified children who lived in areas where TV was available before they were two, and compared them to children who were otherwise similar but lived in areas with no TV access until they were older than two. The families of these children were similar; the only difference was that one child had access to TV early in life and one did not. This is how you draw causal conclusions.And they found that, in fact, television has no impact on childrens test scores. Zero. Zilch. Its very precise, which is a statistical way of saying they are actually quite sure that it doesnt matter. All that research in public health about the dangers of SpongeBob? Wrong. It seems very likely that the reason SpongeBob gets a bad rap is that the kinds of parents who let their kids watch a lot of television are different. Correlation, yes. Causation, no.Just to be clear, Im still a little wary of television, being from one of those families where we could never watch TV. Jesse is not. Occasionally, when he thinks Im not looking, I catch him and Penelope in the basement snuggling on the couch, enjoying some Sesame Street. When I protest, he points to the evidence, and I cant really argue.Pregnancy, like SpongeBob, suffers from a lot of misinformation. One or two weak studies can rapidly become conventional wisdom. At some point I came across a well-cited study that indicated that light drinking in pregnancyperhaps a drink a daycauses aggressive behavior in children. The study wasnt randomized; they just compared women who drank to women who did not. When I looked a little closer, I found that the woman who drank were also much, much more likely to use cocaine.We know that cocaine is bad for your childnot to mention the fact that women who do cocaine often have other issues. So can we really conclude from this that light drinking is a problem? Isnt it more likely (or at least equally likely) that the cocaine is the problem?Some studies were better than others. And often, when I located the good studies, the reliable ones, the ones without the cocaine users, I found them painting a pretty different picture from the official recommendations.These recommendations increasingly seemed designed to drive pregnant women crazy, to make us worry about every tiny thing, to obsess about every mouthful of food, every pound we gained. Actually getting the numbers led me to a more relaxed placea glass of wine every now and then, plenty of coffee, exercise if you want, or not. Economics may not be known as a great stress reliever, but in this case it really is.More than even the actual recommendations, I found having numbers at all provided some reassurance. At some point I wondered about the risks of the baby arriving prematurely. I went to the data and got some idea of the chance of birth in each pregnancy week (and the fetal survival rate). There wasnt any decision to be madenothing to really do about thisbut just knowing the numbers let me relax a bit. These were the pregnancy numbers I thought Id get from my doctor and from pregnancy books. In the end, it just turned out that I had to get them myself.Ive always been someone for whom knowing the data, knowing the evidence, is exactly what I need to chill out. It makes me feel comfortable and confident that Im making the right choices. Approaching pregnancy in this way worked for me. I wasnt sure it would work for other people.And then my friends got pregnant. Pretty much all of them at the same time. They all had the same questions and frustrations I had. Can I take a sleeping pill? Can I have an Italian sub (I really want one! Does that make a difference?)? My doctor wants to schedule a labor inductionshould I do it? Whats the deal with cord-blood banking?Sometimes they werent even pregnant yet. I had lunch with a friend who wanted to know whether she should worry about waiting a year to try to get pregnanthow fast does fertility really fall with age?Their doctors, like mine, had a recommendation. Sometimes there was an official rule. But they wanted to make the decision that was right for them. I found myself referring to my obstetrics textbook, and to the medical literature, long after my Penelope was born. There was a limit to the role I could playno delivering babies, fortunately (for me and, especially, the babies). But I could provide people with information, give them a way to discuss concerns with their OBs on more equal footing, help them make decisions they were happy with.And as I talked to more and more women it became clear that the information I could give them was useful precisely because it didnt come with a specific recommendation. The key to good decision making is taking the information, the data, and combining it with your own estimates of pluses and minuses.In some cases, the existing rule is wrong. In others, it isnt a question of right or wrong but what is right for you and your pregnancy. I looked at the evidence on the epidural, combined it with my own plus and minus preferences, and decided not to have one. My friend Jane looked at the same evidence and decided to have one. In the end, I felt fine eating deli meats; my college roommate Tricia looked at the evidence and decided she would avoid them. All of these are good decisions.So this book is for my friends. Its the pregnancy numbersthe data to help them make their personalized pregnancy decisions and to help them understand their pregnancies in the clearest possible way, by the numbers. Its the suggestion that maybe its okay to have a glass of wine and, more important, the data on why. Its the numbers on the risk of miscarriage by week, data on which fish to eat to make your kid smart (and which to avoid because they could make your kid dumb), information on weight gain, on prenatal testing versus prenatal screening, on bed rest and labor induction, on the epidural and the benefits (or not) of a birth plan. This book is a way to take control and to expect better.Pregnancy and childbirth (and child rearing) are among the most important and meaningful experiences most of us will ever have; probably the most important. Yet we are often not given the opportunity to think critically about the decisions we make. Instead, we are expected to follow a largely arbitrary script without question. Its time to take control: pick up a cup of coffee or, if you like, a glass of wine, and read on.PART 1In the Beginning: Conception1Prep WorkSome pregnancies are a surprise. If youre one of those women who woke up feeling queasy, took a pregnancy test on a whim, and were shocked to see the second pink line show up, congratulations! Please skip ahead.But for a lot of us, were thinking about getting pregnant long before it actually happens. I met my husband in college in 2001. We got married in 2006. Our daughter was born in 2011. I wont say I spent the whole ten years thinking about a baby, but I (and, later, we) did make a lot of choices with at least the long-term plan of having a family.And as I approached 30, and pregnant friends started popping up here and there, I thought a little more seriously. I wondered if there was something I should be doing in advance, even before we started trying to get pregnant. Should I change my diet? My doctor did once suggest I should cut down on coffee, just so it wouldnt be such a shock to reduce when I was pregnant. Was that really necessary?Mostly, I worried that I was getting old.Thirty is not actually old in pregnancy terms. Advanced maternal age is reserved for women over 35, and you wouldnt be faulted for thinking that 35 was a sharp cutoff. I read one paper once that referred to eggs as best used by 35. Thanks, its really helpful to know my sell-by date. But, of course, 35 is not a magical number. Biological processes dont work like this. Your eggs dont wake up on the morning of your 35th birthday and start planning their retirement party.Starting pretty much the first day you menstruate, your fertility is declining. Your most fertile time is in your teens, and it goes down from there30 is worse than 20, and 40 is worse than 30. But, of course, there are other factors that push you in other directions. I certainly wasnt in a good position to have a baby in my first year of graduate school at 23, and the truth is that Id probably be in a better position at 35 than at 30.It wasnt the only consideration, but I did wonder about how fast fertility declined. My doctor didnt seem worriedYoure not thirty-five yet! she saidbut that wasnt quite the detailed reassurance I was looking for.I went looking for reassurance (or, at least, information) in the world of data, in the academic medical literature. As I expected, there was an answer. It just wasnt quite what the over-35 retired-eggs story would have suggested.The main research on this uses data from the 1800s (its old but the technology hasnt changed much!). Here is the idea: prior to the modern era, couples would pretty much get down to business right after the wedding, and there were limited birth control options. So you can figure out how fertility varies with age by looking at the chance of having children at all for women getting married at different ages.Researchers found that the chance of having any children was very similar for women who got married at any age between 20 and 35. Then it began to decline: women who got married between 35 and 39 were about 90 percent as likely to have a child as those who got married younger than 35; women who got married between 40 and 44 were only about 62 percent as likely; and women who got married between 45 and 49 were only 14 percent as likely. Put differently, virtually everyone who got married between 20 and 35 had at least one child, compared to only about 14 percent of those who got married after 45.You may or may not like to draw conclusions from such old data. People live longer now, and are healthier longer. It is certainly possible that as longevity and health increase, women will remain fertile longer. Even if you do take this data at face value, the reduction in fertility is not as dramatic as you might have feared. The 35- to 39-year-old group is only slightly less likely to have children; the major drop in fertility is not until after 40, and at least some women over 45 in this data did conceivethis in an era well before in vitro fertilization (IVF)!Contemporary data looks fairly similar, perhaps even somewhat more encouraging. Researchers in France studied a group of around 2,000 women who were undergoing insemination with donor sperm. One nice aspect of this study is that they didnt have to worry that older people had sex less frequently because everyone in the study was trying to get knocked up at the right time of the month in a controlled environment. After 12 cycles, the pregnancy rate was around 75 percent for women under 30, 62 percent for women 31 to 35, and 54 percent for women over 35. In this oldest group things were similar for women 36 to 40 and over 40. More than half of the over-40 women in the sample got pregnant within a year.1In the end, my doctor was basically right to pooh-pooh my worries. But for me, seeing the numbers this way, in black and white, was far more reassuring. I could see in detail that starting to try at 30 rather than at 28 was not going to make that much difference. I could think about the timing if we wanted, for example, more than one child. And I could see that the numbers were all pretty highfor me, reading 75 percent of women were pregnant with a year was a lot more helpful than hearing things like, It works out for most women. For one thing, how do I know if your most is the same as mine?Id experience this again and again. The value of having numbersdatais that they arent subject to someone elses interpretation. They are just the numbers. You can decide what they mean for you. In this case, its true that its harder to get pregnant when you are older. But its not impossible, not even close.When we did start thinking more seriously about a baby, I stopped focusing so much on age. (After all, what could I do? Not getting older is not exactly an option.) But I did wonder about other things I might do to prepare. I asked my OB at my yearly visit if there was anything I should be aware of. Other than some generic advice to relax (not one of my strengths), the one thing she focused on was exercise. Make sure you are exercising before you get pregnant.When I talked to other women, it seemed like this was part of a more general themeits a good idea to try to be in good physical shape before getting pregnant. Independent of any medical advice, I had long harbored the fantasy of getting to my goal weight prior to pregnancy. I had achieved this weight exactly once in my life, before my wedding, through a process of five A.M. ninety-minute cardio workouts four days a week. I figured if I got to this weight again before we got pregnant, Id be one of those Heidi Klumtype women who look great through the whole pregnancy and are back to bikini modeling eight weeks after giving birth.In the end, of course, I got pregnant right after our summer vacation, not exactly the most weight-loss-friendly time of year. Thats okay, I figured, Im sure it will be easy to get to that goal weight after the baby is born. I am nothing if not optimistic.Other than some feeling of personal achievement, it wasnt clear to me why I should care about my prepregnancy weight. Does it matter for anything? A few pounds here and there, obviously not. Overall, yes. Women (and their doctors) worry a lot about weight gain during pregnancy, but it turns out that weight before pregnancy is much more important.About 70 percent of the U.S. population are overweight (defined as a body mass index over 25), and 35 percent are obese (BMI over 30). (Note: to calculate your BMI, take your weight in kilograms and divide it by your height in meters squared. If you are 5 feet 6 inches and 150 pounds, your BMI is 24.2.) On a number of important dimensions, obese women in particular have more difficult pregnancies than normal-weight women.One study that demonstrates this effectively used a group of roughly 5,000 births at one hospital in Mississippi.2 The advantage of using a single hospital is that it means the women are all pretty similar in terms of income, education, and other characteristics. A large percentage of the women in the study were obese.The authors looked at a very large number of outcomes related to the mothers: preeclampsia, urinary tract infection, gestational diabetes, preterm delivery, the need for labor induction, Cesarean delivery, and postpartum hemorrhage (bleeding after birth). They also looked at some things about the babies: shoulder dystocia (when the second shoulder gets stuck during delivery), whether the baby needed help breathing, the five-minute APGAR score (a measure of the babys condition five minutes after birth), and whether the baby was abnormally small or abnormally large.Obese women have more pregnancy complications, as the graph on the next page illustrates. One example: 23 percent of normal-weight women have a C-section, versus almost 40 percent of obese women. The risk of preeclampsia, a serious pregnancy complication, is more than three times as high if you are obese. Overweight women (not in this graph) fall somewhere in the middlea slightly higher risk for some complications, but the differences with normal-weight women are small.Pregnancy Complications and Prepregnancy ObesityWhen this study looked at infants, the babies of obese women were also more likely to have complications. If you are obese when you get pregnant, your baby is more likely to have shoulder dystocia, more likely to have low APGAR scores, and more likely to be abnormally large for gestational age. Even scarier, children of obese women are at higher risk for death, although this is very rare, regardless of Moms weight.This data is from just one study, but the findings are very consistent with other studies, from the United States and elsewhere.3, 4 And the effects arent limited to outcomes during pregnancy. Obese women have a harder time conceiving, and are more likely to miscarry early in pregnancy.5 There is even some recent evidence that maternal obesity is associated with delays in breast milk coming in, which can impact breast-feeding success.6Baby Outcome and Prepregnancy WeightA review article from 2010 summarizes the literature on this issue with a simple statement: Maternal obesity affects conception, duration and outcome of pregnancy. Offspring are at increased risk of both immediate and long term implications for health.7 In other words, it is harder to get pregnant, harder to sustain a pregnancy, more likely that later-term complications will arise, and more likely that there will be complications with the baby. All of which you would like to avoid.None of this is to suggest that its a problem if you cant lose that last five pounds, of course. The outcomes here are a result of pretty large differences in weight. I may have been disappointed not to get down to my fighting weight, but it is unlikely that it mattered. And being too skinny can also interfere with conception. But it does suggest that there are real benefits to getting your weight under control before you get pregnant. Of course, weight loss may have health benefits for reasons other than pregnancy. See, your (hypothetical) baby is helping out already!The Bottom LineFertility declines with age, but not as fast as you might expect35 is not a magic number cutoff.Being obese before pregnancy is associated with an increased risk of complications for both you and your baby. Dont worry too much about a few pounds here and there, but if you are significantly overweight, weight loss before pregnancy may have benefits.2Data-Driven ConceptionI spent most of my twenties trying not to get pregnant. I used at least three versions of the birth control pill and even, for a brief time, something called The Patch. So I knew I was really good at not getting pregnant. Of course, I worried that perhaps I wouldnt be so good at getting pregnant.Id like to say that I approached the process of conception in a laissez-faire way. After all, I was only thirty, we had plenty of time, and there was no indication that wed have trouble conceiving. I wish I could say I was like my sister-in-law, Rebecca, who was so relaxed about this with my nephew that she was two months along before she even realized she was pregnant.But this doesnt really fit with my personality. I suspected even before we got down to business that I would be a neurotic mess. I was correct. I actually had a panic attack about this before we even started trying. It must be a record. When I went to my primary care doctor, she looked at me thoughtfully and suggested that perhaps knowing more about the process would help me relax (even if I couldnt actually control it).I dont know why this hadnt occurred to me before, but she was exactly right. On her recommendation, I picked up a copy of Taking Charge of Your Fertility and read it cover to cover.The main thing I learned was that a lot has to go right to get pregnant. Its kind of amazing that the human race continues to exist at all.You probably remember the basics of conception from health class: unprotected sex, sperm meets egg, and, all of a sudden, youre pregnant. High school health class tends to give the impression that pregnancy is really, really likelypart of the general scare-tactic attitude. But, in fact, the majority of the time it is not possible to get pregnant. The key issue is timing: you need sperm to be around at the exact moment that the egg is ready.When is that? The average woman has a menstrual cycle of 28 days, counting from the beginning of one period to the beginning of the next. The first day of your period is considered day 1. The week of your period and the week after it are preparation for ovulation. About 14 days after your period starts the egg is released (this is ovulation) and begins to travel down toward the uterus.The egg is available for fertilization during this journey, which lasts a couple of days. If the egg meets a sperm on its way to the uterus and the sperm gets lucky, fertilization occurs. If you happen to release two eggs and they both meet sperm, you get twins; twins can also happen if the fertilized egg divides right at the beginning. When the fertilized egg (or eggs) reaches the uterus, implantation occurs and pregnancy actually begins. The process from egg release to implantation lasts 6 to 12 days. For most successful pregnancies, implantation occurs 22 to 24 days after the first day of your last period.1This whole second half of the cycle (after the egg is released) is called the luteal phase. Its either taken up with fertilization and implantation (if you get pregnant) or with the egg waiting around in the uterus to be flushed out during your period. If you do not get pregnant, day 28 will bring your period. If you do get pregnant, day 28 will roll around periodless, and youll be off and running. Heres the basic timeline (this is for someone with a standard 28-day cycle; if your cycle is a few days longer or shorter you might ovulate a bit earlier or later than day 14):The key to pregnancy is that when the egg starts making its way down the tube, the sperm has to be waiting for it. This means the best time for sex or insemination is the day before or the day of ovulation. It takes some time for sperm to swim into the fallopian tubes, so the day after ovulation is generally too late.Sperm are, however, a bit more robust than the egg. They can typically live up to 5 days in the fallopian tube, waiting. This means the window is actually a bit longer. Sex 4 or 5 days before ovulation can lead to a baby, although its less likely. I was curious about how much less likely. All this talk about a small ovulation windowwas there really any truth to that? How small was the window?Figuring this out actually requires knowing quite a lot about peoples sex lives. Fortunately, at least some researchers are up to the challenge. I found a study that followed more than 200 couples who were trying to conceive for more than a year. The authors recorded detailed information on when they had sex and collected their urine daily (daily!) so they could monitor both ovulation and pregnancy.2 Using this information, the researchers figured out the best timing for baby-making sex (this wasnt the goal of the study, just an auxiliary fact we can learn from it).What makes this question a bit tricky to answer is that most couples trying to get pregnant have sex frequently. This makes it hard to know which sex act led to the babywas it the sex you had on the day of ovulation? Or three days before? The researchers get around this by focusing on women who had sex just one time in the plausible conception window.Using these one-day-of-sex people, we can figure out the chance of conception by day. Here it is:Probability of Conception by Cycle DayFor most of the month, pregnancy is impossible (at least based on these data). No one conceived by having sex after ovulationby the time the sperm gets up into the fallopian tubes, the egg is long gone. In addition, no one conceived by having sex more than 5 days before ovulation.The window of possible conception is short: from 5 days before ovulation through the day of ovulation. But note that if you time it right, the chances of pregnancy are good. Conception rates are more than 30 percent for the day before and the day of ovulation! These odds are really not bad.If you had to pick just one day in the month for sex, youd want to pick the day you ovulate (or the day before: the pregnancy rates are similar). If you are using artificial insemination, it also makes sense to focus on the day before and the day of ovulation, when fertilization is most likely. For most women with a standard 28-day cycle, this is around the 14th day after your period starts.Of course, one way to make sure that you definitely have sex on the day of ovulation is to have sex every day around the possible ovulation day (or just have sex every day). This technique is typically pretty popular with husbands, at least in the first month or two. But some OBs will warn you off this. I was told that the best strategy is to have sex every other day. If you did this, youd be sure to capture at least one of the two best days, and the argument is that if you (or your partner) save up the sperm, then pregnancy chances are increased. On the other hand, saving them too much (say, skipping sex for more than ten days) tends to cause their effectiveness to diminish.3This always sounded a little suspicious to me. I can easily believe that the amount of sperm is higher if you wait a day, but could it really be more than twice as high, which is what would have to be true for the every-other-day plan to beat out the every-day plan?It turns out my skepticism was somewhat well placed. The same paper that gave me information on the right day for sex also determined whether frequency of intercourse mattered. The researchers calculated the predicted chance of pregnancy for people who had sex once during the 6-day window leading up to ovulation, for those who had it twice, three times, and so on. The chances were almost identical. In other words, there seems to be no benefit to alternating sex days, having sex more frequently, or having sex less frequently. The crucial thing is to hit the day of ovulation or the day before.This appeared to make things simple. All I had to do was figure out when I was going to ovulate, and then have sex that day or the day before. I figured this wouldnt be that hard, although I worried a bit about work travel, and I patted myself on the back for having avoided what the fertility book suggested was the major infertility pitfallnamely, not having sex on the right day.There was just one remaining problem: I didnt seem to be ovulating at all. Or, at least, things didnt seem to be behaving normally. When I went off the pill, my doctor said my cycle would return to normal (or return to whatever it was before I went on the pill, as if I could remember that). She said it would happen within three months. It didnt. I went two months between periods, then had two within a few weeks.I called the doctor at 3 months and 1 day. What is going on? I asked the nurse when she called back. Should I be worried? What should I do?What I wanted was a concrete answer. Something like: 70 percent of women resume normal cycles within 3 months, 90 percent within 6 months. I wanted to know whether it mattered that I had been on the pill for 12 years. Would it take longer to get back to normal? This is not what I got. What I got was best described as vague reassurance (and the ever-helpful Just relax!).I thought if I pushed, I would get to the more detailed evidence, but I didnt. Everyone is different, I was told. Yes, that is why I asked about the average, I grumbled to Jesse. I would have this type of experience again and again. How accurate is the prenatal screening they suggested? Quite accurate. When should I expect to go into labor? Its a different time for everyone.I wanted a number. I craved evidence. Even if the answer was that the evidence was flawed and incomplete, I wanted to know about it. Yes, I understood that everyone was different. But that doesnt mean there isnt any information!Again, I headed out on my own to look for the numbers.The most popular temporary forms of birth control in the United States are (in order): the pill, condoms, IUDs, and the withdrawal method. Obviously, neither condoms nor the withdrawal method have any impact on your menstrual cycle. If youve been using condoms, whatever cycle youve had up until now will continue. Same for withdrawal, and for any other barrier method (diaphragm, Today Sponge, etc.).The pill makes things more complicated. As my doctor noted, sometimes the cycle returns to normal right away, but sometimes it takes a bit longer. The advantage of referring to the actual studies is that we can be more precise. In one study in Germany,4 researchers studied menstrual cycles of women who just went off the pill. For some women it took up to 9 months to get back to a normal cycle. In the initial months after going off the pill these women had longer menstrual cycles, were more likely to have cycles in which they didnt ovulate, and were more likely to have cycles where the second half of the cycle (the luteal phase) was so short that pregnancy was unlikely.This study is similar to others. Researchers in the United States studying women who had gone off the pill in the last 3 months found they had longer cycles (by a couple of days), more variable cycle length, and later ovulation in some cycles than those who had been off the pill longer.5 In addition, when researchers measured their cervical mucus, the women who had been off the pill longer had cervical mucus that was more welcoming to the sperm.The very good news, however, is that these effects are relatively short-lived. In the German study, virtually everyone had a normal cycle by 9 months after going off the pill. For some women it is much faster: 60 percent of women in that study had a normal cycle the first month off the pill.I was also reassured that once you do ovulate, having been on the pill doesnt seem to impact pregnancy rates. In another German study,6 researchers studied women actually trying to get pregnant. They found that women who had just gone off the pill were slightly less likely to get pregnant in the first 3 months of trying, but no less likely to be pregnant within a year. This study also looked at the duration of pill usage and found no effect: even for people like me, who had been on the pill since their teenage years, things went back to normal in the same basic time frame.What I took from this was that worrying at 3 months and 1 day was unnecessary. If I got to 9 months without things normalizing I could consider stressing out a bit.Fewer women use IUDs, but the rates have crept up in the last decade. As with the pill, it takes a bit of time to recover fertility after using an IUD. In a recent literature review, authors found that women who had just gone off an IUD took (on average) a month longer to get pregnant than those who had just stopped oral contraceptives, but 80 to 90 percent (depending on the study) were pregnant within one year.7So I waited, and a couple of months later things normalized a bit, just like the data said they would. But I still needed to figure out when I was ovulating. Day 14? Day 16? Day 12? Even after 6 months my cycle wasnt completely regular; I couldnt just assume it was day 14. Also, I quickly figured out that this was an opportunity to collect data. I couldnt resist!There are three common ways to detect ovulation: temperature charting, checking cervical mucus, and pee sticks. The first two of these have been in use for many years; the pee stick method is relatively new.Temperature Charting: Temperature charting (sometimes called BBT charting, for basal body temperature) relies on the mildly interesting fact that your body temperature is higher in the second half of the month, after ovulation, than before. You can therefore figure out when you ovulate by taking your temperature every day. The technique itself is not complicated. Every morning before you get out of bed (moving around affects your temperature; you ideally want to take it as soon as you wake up, before you do anything), you take your temperature using an accurate digital thermometer.For the first half of the month, your temperature will be lowtypically below 98 degrees. The day after ovulation, it will jump up, usually at least half a degree and sometimes more. This is the sign that you ovulated. Your temperature will stay high through the rest of the month, and then drop on the day your period starts, or (often) the day before. If you get pregnant, your temperature will stay high.There are some very good things about temperature charting. In the month you are doing it, it can tell you with high certainty that you did, in fact, ovulate. If your cycles are regular, it can help you plan for the next month by showing you the day on which you generally ovulate. It can also tell you that you are pregnant. More than 14 days of high temperatures is a very good indication of pregnancy.However, this isnt perfect. The biggest issue is that it tells you only after you ovulate. So although it is useful for predicting the next month, it doesnt help with this month. Also, its not as simple as it seems. To really make this work you need to take your temperature at the same time every day, ideally first thing in the morning after four to five hours of continuous sleep. The results can get screwed up by jet lag, a fever, or a bad night of sleep.I liked this method a lot, if only because it enabled me to feel like I was doing something proactive every day (and because it produced data, which I could use to make attractive charts). The downside is that I was never especially good at it.My temperature chart from the month that I got pregnant with Penelope is on the next page. On one hand, the fact that my temperature eventually elevated and stayed up gave me a (small) clue that I was pregnant. On the other hand, all the jet lag and my generally poor sleep meant that it was almost impossible to interpret. I initially thought I ovulated on June 9 because my temperature went up on June 10; then I realized this was just because of the time change when we got back from Europe. The sustained higher temperatures did not occur until I got back from Ghana. The only way I knew that I must have ovulated before that trip was that Jesse wasnt there!Basal Body Temperature Chart, June 2010We can be a little more scientific about how useful this is for the average woman. In a study from the late 1990s,8 researchers followed a set of women trying not to get pregnant and evaluated how good various methods were at detecting ovulation. In this study they were able to pinpoint the actual date of ovulation using ultrasound, so they knew the truth. The temperature-charting method as used by these women accurately identified the day of ovulation about 30 percent of the time. Another 30 percent of the time this method pointed to ovulation one day before it actually occurred.That day before ovulation is also good for pregnancy sex. Putting this together: if you have sex on the date indicated by temperature charting, 60 percent of the time you would manage to time sex on one of the two most fertile days of the month.Cervical Mucus: If you really want to get serious about natural ovulation detection, you probably want to chart your cervical mucus along with your temperature. This is a bit more complicated than temperature charting and, at least for some women (read: me), there is an ick factor. Heres the idea: right around ovulation your body produces a type of mucus ideal for sperm to swim through. You can detect this mucus in and around your cervix. is there an app to keep track of books read Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong--and What You Really Need to Know
180 of 184 people found the following review helpful. My #1 go-to pregnancy book! Does not treat you like an idiot.By AU-AUIt's a pity this book got caught up in a kerfluffle about alcohol, when that is about 1% of the books actual content (I've put *exactly* what the author says about it at the bottom of the review for all those negative reviewers who couldn't be bothered reading the actual book!).This book was hands down the most useful pregnancy book I read, not because it tells you what to do, but because it calmly presents the data on every major decision you'll need to make during pregnancy, and then encourages you to form your *own* opinions based on it, instead of treating you like an idiot who can't be trusted to understand anything other than black-and-white 'rules'. As the author says:"I teach my students that making good decisions requires two things. First, the right data. Second, the way to weigh the plusses and minuses of the decision *to you personally*...So naturally, when I did get pregnant I thought this is how pregnancy decision making would work too. Take something like amniocentesis. I thought my doctor would outline the plusses and minuses...She'd give me the data I needed. She'd then sit back, and my husband and I would discuss it and we'd come to a decision that worked for us. This is not what it was like *at all*".Every pregnant woman knows this feeling.This book has the missing data that thinking parents need to help them make many of those decisions, including:- What *really* happens to your odds of conception after 35?- What is the evidence that having a cup of coffee will harm your baby? or 2 cups? 3 cups? Why is there so much conflicting advice on this?- Same for alcohol, by trimester- What is the likelihood of miscarriage each week? (I found this super reassuring)- What is the statistical likelihood of issues arising from eating deli meats, eggs, fish, shellfish, soft cheeses, and sushi? How do you weigh up the omega 3 vs mercury risk for fish?- What % of women are still experiencing morning sickness each week? Are your morning sickness symptoms 'worse' than the average woman and how risky are the drugs for it?- What should you know before you make a decision to get antenatal testing for downs syndrome? Does amniocentesis really have a 1 in 200 risk of miscarriage? Is CVS more or less risky than amnio? (We ended up having the non-invasive test, while getting our results the doctor told us 'you seem really well informed on this!'. Thanks Emily :-)- Is emptying the cat litter box as dangerous as gardening?- Exactly how much airplane travel is risky?- What are the real risks (and benefits!) of gaining more weight than the recommended amount?- Is there anything that will help you correctly guess the gender?- What's the evidence on whether Kegels help?- How can I understand the data on which drugs are safe during pregnancy?- What is your chance of a pre-term birth, week by week? And what % of pre-term babies at each week will survive? (also reassuring)- For full term babies, what is the chance of the baby arriving each week, if it didn't come last week? Are there any studies than show symptoms the baby might come soon? Is there anything safe you can do to bring on labor if you are overdue?- What are the risks and benefits of induction? Do you really need to be induced for 'low amniotic fluid'?- How long does the average labor really take?- What, statistically, are the pros and cons of a c-section or an epidural? What about cord-clamping, homebirth, doulas, types of fetal monitoring, episiotomy, and cord blood storage?- An example of an evidence-based birth plan is included, but emphasis given to choosing what works for you.So, in summary, the data need to make your own important decisions along the way. Recommended read!--------Appendix: *Exactly* what this book says about alcohol during pregnancy:"There is no question that very heavy drinking during pregnancy is bad for your baby. Women who report binge drinking during pregnancy are more likely to have children with serious cognitive defects. In one Australian study, women who binged in the second and third trimester were 15 to 20% more likely to have children with language delays than women who didn't drink. This is repeated again and again in other studies. Binge drinking in the first trimester can cause physical deformities and in later trimesters, cognitive problems.If you are binge drinking, stop.However, this does not directly imply that light or occasional drinking is a problem. When I looked at the data, I found no credible evidence that low levels of drinking (a standard glass of wine or so a day) have any impact on your baby's cognitive development"(The author then goes on to review a number of studies in more detail, including an analysis of whether those studies correctly separated causation from correlation).------------I did not read that as a licence to go drinking while pregnant. In fact, I read it and chose not to drink anyway (I was too morning sick to want anything to do with alcohol!). And I respected the author for giving me the evidence, and not blindly repeating something others had said.Here's to being treated with respect when you are pregnant, not like an idiot.615 of 659 people found the following review helpful. Fact-based book for empowered pregnancy choicesBy Caroline NiziolIf you asked me a couple of weeks ago if I was interested in reading Yet Another Pregnancy Book, I would have laughed. Hardly! I read a couple early on, then turned to the almighty Google when I had questions or curiosities. Then about a week ago, my mom clipped an excerpt from the Wall Street Journal called "Take Back Your Pregnancy." Well, I took the bait. Emily Oster's article intrigued me. Definitely one for any subsequent pregnancy, I thought!Then the furor struck on the Interwebs. Because Oster draws the conclusion from a variety of studies and data that it's fine to indulge in the occasional alcoholic beverage during pregnancy, she has been excoriated in a variety of articles and in the responding comments. Current .com reviews are skewed by those who take issue with an economist (not a medical doctor) who will, in their minds, increase the number of children born with FASD (Fetal Alcohol Spectrum Disorder). Several comments made nasty remarks about the author's 2-year-old daughter, Penelope, implying that it was only a matter of time before she would begin to fail IQ tests and demonstrate signs of FASD herself.Was Oster truly that horrible and conniving? Did she write her book to cause birth defects and emotional trauma? I had to know the truth, and while 40 weeks and two days pregnant, I picked up Expecting Better and read it carefully.Spoiler alert: it's really not that bad. I love authors who examine evidence, explain scientific studies and methodology, and draw logical conclusions about the data. Oster isn't an ob/gyn, but she's a well-trained economist whose job is interpreting data. Her analysis is thorough even as she keeps her writing accessible, humorous, and sympathetic. As she points out in the introduction, advice about pregnancy tends to be either black and white--don't have any drinks, ever--or vague--drink coffee in moderation. Instead of relying on the hearsay, she reviews the actual data and comes to her own conclusions. Oster doesn't demand that women drink during pregnancy despite their own reservations. Not at all! She just presents the evidence that light drinking has been shown to be not harmful, and lets the reader make her own choice.The knee-jerk reactions to the book and Oster's approach are misguided because they don't realize that telling women what to do during pregnancy is exactly the opposite of Oster's intentions. Rather, she wants all the data laid out so women can make informed decisions during pregnancy based on their own assessment and comfort levels with varying amounts of risk. That is far more empowering and practical than a notarized list of what to do and not do. She gives examples in the text, citing instances where her review of the data prompted her to chose one path and a friend reviewing the same data to chose another path. That is fine. The goal is seeking knowledge to inform personal decisions.Pregnancy in the U.S. is fraught with judgment from family, friends, and total strangers that add extra stress in an already anxious time. Expecting Better steps back from the hysteria and offers women up-to-date, relevant information about the choices they will need to make during pregnancy. I'll definitely be recommending this one to pregnant friends in the future.1 of 1 people found the following review helpful. Brilliant book that speaks in an informed and thoughtful manner.By S.Obsessed with Emily Oster and this book. SO GOOD. And readable and clear. She offers reasonable data/studies driven information. The only pregnancy book I have found that does not talk down to the reader or act as if the mom-to-be is a semi-literate child. Everytime I get nervous I refer back to the pertinent chapter and refresh myself on the actual numbers.