CHANA JOFFE-WALT, HOST:
When I was pregnant with my first child, I used to count the number of times I felt him kick before I fell asleep. This is a thing they tell pregnant women to do. You know, you want to make sure the baby is moving so you're supposed to count how many times you feel kicks same time every day.
And so one night, I'm about eight months pregnant and I'm doing this. I'm counting the kicks, and I feel a few less than normal. And I try not to get too nervous. I did it again a couple of minutes later and it was totally normal. But the next morning, I was still thinking about it. And so I called my doctor, and my doctor said, oh, it's no big deal. Don't worry about it. But go to the hospital as fast as you can. So no big deal, but go to the hospital. So now I'm worried.
And of course, I race to the hospital. Within minutes of walking into the hospital, I'm hooked up to a fetal heart monitor and they're taking my blood pressure. There's, like, a group of nurses whispering over my chart.
At some point, a specialist is rushed in. Somebody mentions an emergency delivery. And this goes on for hours, and then a nurse throws open the curtain to my little room and says, OK, you're good to go. You can get dressed now.
And I'm like no, wait, what about the kicks not being regular and all these tests you're doing? And she just sort of shrugs and says, oh, yeah, sometimes the kicks aren't regular, it happens. It's no big deal. You should get dressed, go to work, which in the end I do.
ALEX BLUMBERG, HOST:
And then we just looked back at the calendar, you apparently came to work and tracked episode 264 of the PLANET MONEY podcast.
JOFFE-WALT: I remember it well. It was about whether or not politicians can create jobs.
BLUMBERG: And you're here right now tracking episode 481 of the podcast. Hello and welcome to PLANET MONEY. I'm Alex Blumberg.
JOFFE-WALT: And I'm Chana Joffe-Walt. I should say I have a very happy, healthy 2-year-old boy at home. There was no problem with the kicks. And recently I actually did the whole pregnancy thing again. I now have a new baby who I'm home with right now.
BLUMBERG: And you have actually come into the studio from your maternity leave to track this podcast because you've been thinking about that episode a lot and sort of, like, the experience of pregnant.
JOFFE-WALT: I think about that day in the hospital all the time because that, in my experience, is what American pregnancy is like. It's this bizarre world where there's only two states. There's everything's fine, nothing to worry about or total emergency. There's not a lot of information about what lies in between. Like, the rest of our lives are lived in the gray area in between total emergency and everything being fine - not so in pregnancy.
(SOUNDBITE OF RAMONES SONG, "BABY, I LOVE YOU")
BLUMBERG: Today on the show, we're going to meet a woman who's trying to make pregnancy more like the rest of our lives, where there are gray areas, you know, where a little alcohol is probably fine, lots of alcohol could be trouble versus the black-and-white world of pregnancy where no amount of alcohol is considered safe.
JOFFE-WALT: OK. So let's just get to it. Her name - that woman is Emily Oster. She's an economist. She's been on our show before. And she's written a new book called "Expecting Better: Why The Conventional Pregnancy Wisdom Is Wrong And What You Really Need To Know." And Oster, like me, found herself recently pregnant and also really frustrated by the black-and-white world of pregnancy rules. But unlike me, Oster decided to read almost every study that has ever been conducted on pregnancy and risk because from the very beginning, she was finding that there were tons of rules, a long list of rules of things that you are supposed to do or you're not supposed to do and you are supposed to eat or you're not supposed to eat. And all those rules were very black and white. And many of them contradicted each other. Here's Emily Oster.
EMILY OSTER: No coffee, no smoking, no sushi, no soft cheeses, no - no deli meats. Sometimes they'll tell you no peanut butter, sometimes they'll say have more peanut butter, no swordfish. There's many fish restrictions. Sometimes they'll tell you not to clean the litter box if you have a cat, sometimes not or, like, putting your deli meats in the microwave.
JOFFE-WALT: (Laughter) Yeah, I heard that one.
OSTER: You microwave your ham. Who tells you that?
JOFFE-WALT: Did you do that?
OSTER: Get pregnant - no, I didn't do that.
JOFFE-WALT: And when you read about these rules, there's often a very simple explanation, like no swordfish because it's high in mercury or no deli meats because you might get a bacterial infection. But Oster wanted more context. She had more questions like, well, if I microwave my ham, does that eliminate my risk of bacterial infection completely? Does it reduce it by half, by some infinitesimal, tiny amount?
BLUMBERG: And how big is that risk in the first place? Like, how big is the risk of bacterial contamination from deli ham? And what is worse, you know, drinking coffee or unmicrowaved ham. There's no way to sort of gauge.
JOFFE-WALT: Right. And then there was the issue of Emily Oster's weight. So this is a weird thing, you're healthy most of your life, you don't go to the doctor that much. And then when you become pregnant, you're going to the doctor every two weeks. And the first thing they ask you is you need to get on the scale and they want to have a discussion with you about your weight.
OSTER: Of course, I was always in trouble. I'd gained too much weight, too - it was too fast. You know, at some point, I was told if you keep gaining at this rate then when you have the baby you will have gained 36 pounds and your limit is 35. I say can you explain to me how that would matter? And they said, well, here - that's the rule. The rule is for someone who starts at a normal weight they should game between 25 and 35. It was like, well, what's going to happen if I don't do that? It's like, well, we don't recommend you go outside the rule.
But there was like no - it was like - but and, like, what's going to happen? Will I explode? Will the baby just explode out of my stomach like "Twilight?" You know, is that what we're worried about. Can you give me some sense of this, of, like, how big a deal is this? And I think there were many things like that where I just thought surely the answer can't just be just because.
JOFFE-WALT: Emily Oster told me she had this idea before she became pregnant that, you know, she was going to go in with her doctor and sit down and basically have a conversation about tradeoffs. You know, she's an economist, so she assumed that there would be some discussion of all the available evidence and the risk associated with, you know, gaining too much weight and then she could weigh that risk against her desire to eat cookies or whatever.
But the evidence is never presented like that. Popular pregnancy books don't lay out the various risks associated with all these rules. And doctors don't really either.
OSTER: My doctor was wonderful at many things, and there is no doubt, you know, when I was actually producing the baby, I was glad that there was a doctor. But in the end, you know, they think that training in medical school is not as suited to interpreting this kind of evidence or doing this kind of decision making as the training that I had as an economist.
BLUMBERG: Because when you think about what economists do, it's pretty much the opposite of offering simple, black and white do's and don'ts...
OSTER: That is a...
OSTER: ...Never, ever do if you're...
OSTER: ...An economist.
BLUMBERG: There are actually legendary jokes about economists making this very point. Like, Harry Truman famously said I want a one-handed economist because I'm tired of them always saying, well, on the one hand, on the other hand.
JOFFE-WALT: And Emily Oster lives in that world. You know, what she does is she studies how people make decisions, how lots and lots of people make decisions. And she assumes that people are making those decisions based on their knowledge of the risk associated with each choice. Like, you know, jaywalking, there's some amount of risk that you're going to get hit by a car. But you do it sometimes because you want to get where you're going faster. You're always weighing those costs and benefits. And Emily Oster's job is to study the way in which we do that, the tradeoffs that we make.
BLUMBERG: And so the way economists study this world is actually pretty much the same way that, you know, sort of public health medical researchers do it. They get big, big groups of people and they look at their behavior and try to figure out which behaviors are causing which outcomes.
JOFFE-WALT: Which can be hard to do because say an economist is trying to figure out how schooling affects your salary later in life. And you could say more schooling affects your salary. It gives you a higher salary later in life. But, of course, maybe also that group of people that you're looking at lived in a rich neighborhood, and maybe it was the fact that they were from rich parents and that's why they had a higher salary later in life. You don't know. In the real world, it's really hard to tell what causes what.
BLUMBERG: And of course, the same is true with these medical studies trying to determine which behaviors can be blamed for bad health. And Emily Oster assumed that that was probably true for pregnancy rules as well, that the actual data was hard to disentangle and it was hard to positively identify cause and effect and that these hard-and-fast rules were basically masking all that uncertainty. For example, one of the main rules, the rule that most people have heard of, even if they haven't been pregnant, don't drink when you're pregnant, right?
JOFFE-WALT: Right, alcohol and pregnancy - bad.
BLUMBERG: Yes. But Emily Oster, when she became pregnant, started wondering what I think a lot of pregnant women wonder, really,
BLUMBERG: not just one drink? I can't have just one drink, not even moderate drinking?
JOFFE-WALT: Right, what about my cousin's wedding? I can't have one last one?
BLUMBERG: Right. Is that really going to have consequences for my child's health down the line? And so she started looking into the studies, trying to isolate the effects of moderate alcohol consumption.
OSTER: There's, like, one paper - it was actually published in a good journal - and it showed that, you know, when you compared women who had never drank to those women who had, like, one or more drinks a day, there was some evidence of more child behavior problems among the drinkers. But then when I looked at the study a little more, there were also very big differences across these groups in how much crack cocaine they used. And I was sort of thinking like, oh, I'm not going to use any crack cocaine. And also, this population, you know, of, like, women on crack in Detroit in the 1980s, like, doesn't seem very applicable here. Maybe it was the crack and not the one, you know, glass of merlot that was, like, really doing them in.
JOFFE-WALT: And Emily Oster found a lot of the studies were complicated in this way. There were other factors that may have explained bad outcomes, and there were lots of studies that showed that there were no bad outcomes.
BLUMBERG: And this study, by the way, she's - is one that was cited quite often. This is not sort of an outlier study. This is one that gets mentioned in research...
BLUMBERG: ...That you got referred to.
JOFFE-WALT: Right. It's one of many. But it is one that many OBs talked about. And when I asked around, I got a variety of responses. You know, doctors said, OK, well, in that study, they do try to control for cocaine in the research. And a few doctors told me, listen, there are, like, 40,000 papers on alcohol consumption, and many, many of them show that alcohol consumption while pregnant can lead to bad outcomes. But, you know, most doctors also said, yes, it's very hard to isolate what happens with small amounts of alcohol. We can see that there's bad effects with large amounts of alcohol. It's harder with small amounts of alcohol. But that doesn't mean that there aren't any negative effects.
BLUMBERG: Also, another thing that you hear from doctors is they say, listen, we have to talk to people all the time. If we try to fine-tune this message, you don't know what people think of as moderate drinking.
JOFFE-WALT: What's moderate?
BLUMBERG: What is moderate...
BLUMBERG: ...Right? Like, one person's moderate might be another person's sort of, like, once-in-a-lifetime binge night.
JOFFE-WALT: Right. And also, I mean, doctors are also afraid of being sued, and doctors try to give you the safest possible advice to protect themselves as well. But mostly it just seems sensible to say, why take unnecessary risks? No amount of alcohol is proven safe. That's actually a thing that you hear all the time from doctors. No amount of alcohol is proven safe, so don't drink any.
BLUMBERG: Emily Oster is not a fan of that line of reasoning.
OSTER: There are many things which haven't been proven safe. You know, maybe being on the radio in - during pregnancy hasn't been proven safe. You know, I haven't seen any good studies showing that that's OK for you. And so in a sense, like, I don't quite know how to parse the statement it hasn't been proven safe. And having seen many, many, many studies in which women who drink a small amount have exactly the same child outcomes as people who don't, you sort of wonder, like, what do you need for proof? In the end, what I found was although it is very clear that drinking too much is bad - I mean, if you have five drinks a day, that's really bad and definitely people should not do that. But in fact, it's very, very hard to find any evidence that suggests that having, say, one drink a day is going to have any negative consequences. I just found that, like, incredibly surprising.
BLUMBERG: Oster's book is basically her going through the data on almost every pregnancy rule out there and looking at the studies and trying to, like, figure out the gray area here, right? She looks at this long list of banned foods. And in case any of you out there are pregnant and wondering about this stuff, quick cliff notes - she finds soft cheeses and deli turkey are in fact to blame for enough bacterial infections that they're probably worth avoiding, but sliced ham gets by fine.
JOFFE-WALT: Right, which I actually found helpful because I feel like when you see the whole list along with sliced ham...
BLUMBERG: Because we know how much you love sliced ham.
JOFFE-WALT: I just - when you see a whole list and sliced ham, putting ham in the microwave, is included on the list, you think the whole list is nonsense. But she's actually saying some of it is really serious. Like, you really shouldn't have soft cheeses. And she's just trying to give you a framework to think through the probability of a bad outcome and then decide how much risk you're comfortable with.
BLUMBERG: I've got to say here, like, I'm a pretty data-driven guy. And I like this approach in theory, sort of, like, mapping out the gray area - here's where you fall - and sort of empowering you to make your own decision. But there is this one part of the pregnancy world where they actually do it that way, right? It's the - you know the nuchal screening? Did you hear of that?
JOFFE-WALT: Oh, right. Right.
JOFFE-WALT: The genetic screening.
BLUMBERG: It's the genetic screening. And they basically take a picture of the fetus and then based on how long it is, I believe, you know, sort of, like, based on the dimensions of the picture, they can sort of assign a probability to - whether or not there's genetic problems in the fetus, right? And so you have this thing. They take this picture, they look at it and then they give you a number. And I remember we had that happen with our first kid. And it was, like, there's a 1 in 10,000 chance that our son could have some sort of genetic abnormality.
JOFFE-WALT: Right. They don't tell you you're fine. They tell you here's the actual risk.
BLUMBERG: Yeah. And I don't think I wanted that number. I don't think I wanted 1 in 10,000 because I have no idea - what does 1 in 10,000 mean? Like, I understand that 1 in 10,000 is a better risk than 1 in 100, but I'm not - I can guarantee you I'm not evaluating that number properly. All I hear, really, is the one (laughter).
JOFFE-WALT: You just hear the one (laughter)...
BLUMBERG: Right (laughter).
JOFFE-WALT: ...Not the 10,000.
BLUMBERG: And I'm like - not the 10,000. And so you're sort of like, if I'm basically fine, I just want to be told OK, your son's fine.
JOFFE-WALT: Right. You don't want complexity. You just want the simple, hard and fast you're OK.
BLUMBERG: Yeah, we are not very good at thinking probabilistically. Humans aren't.
JOFFE-WALT: And actually, when we do look at the data, when we are looking through those exact numbers, we're pretty bad at drawing conclusions from it. We often draw...
JOFFE-WALT: We often draw the wrong conclusions from numbers like that. And Emily Oster actually talks about this phenomenon. She said it came up right after she went to her very first appointment and she heard her baby's heartbeat. You know, at that appointment, they usually tell you the baby's heart rate.
BLUMBERG: Like, what it actually is, how many beats per minute.
JOFFE-WALT: And she left that appointment, and she went to share the details excitedly with the rest of her family.
OSTER: And my mother-in-law was like, well, that means it's a girl. And it was like, all right. And she's like, you know, that - a fast heartbeat means it's a girl. And, you know - and then she had this, like, story which was about her OB when - you know, 30-something years ago who had correctly predicted both my husband and his sister, both of their genders, using this great heartbeat tool.
JOFFE-WALT: Emily Oster had never heard of this.
OSTER: And so then I looked into this. And there's some paper which, you know, starts with something like many people's families think that the heartbeat is predictive. And then it - you know, it just had some - this is a very simple study. They have, like, a thousand women, they listen to the heartbeat, they see the gender. And it turns out, you know, nothing. Like, absolutely no evidence that this is related at all in either direction. And so I showed my mother-in-law, and she was like, that's nice, but I think - I still think I'm right. That study is very nice, but I'm not interested in that...
JOFFE-WALT: Right, I have...
JOFFE-WALT: ...Two data points...
JOFFE-WALT: ...That I can...
OSTER: And then, of course, it turned out we were having a girl. So then she's like, oh, I have three data points.
OSTER: So it's infuriating. She's working her way up to that guy's study, you know?
JOFFE-WALT: (Laughter) Right. One baby at a time.
OSTER: One baby at a time.
JOFFE-WALT: I - every time I think about that story that Emily Oster told, I think of, like, how many grandmothers have said to their children, like, well, I smoked and drank when I was pregnant with you - you know? - and you turned out OK. What's the big deal?
BLUMBERG: Right. Exactly. And that's the problem with data. It's up against, you know, sort of our massive inability to process data correctly, right (laughter)?
JOFFE-WALT: And our love of anecdote and personal experience, especially when it comes to something that is very personal and intimate like pregnancy and child bearing. And parenting is like this, too. Parenting - it continues after you're pregnant. It's, like, full of ideology.
BLUMBERG: Right. And so you understand why the medical establishment - like, when you're up against all this ideology, it's just like in politics. You can't fight ideology with nuance. You have to fight it with simple, powerful phrases. That's why political campaigns are the way they are. And, you know...
JOFFE-WALT: That's why they're called campaigns.
BLUMBERG: That's why they're called campaigns. And literally they call them public health campaigns as well. As any campaign consultant will tell you, you have to keep it simple.
JOFFE-WALT: Yeah. And Emily Oster, in her book, she has internalized that advice. At the end of each chapter - you know, you read through all this complex research and her analysis of it, and then in the end she gives you these simple, easy bullet points about what you should worry about and what you shouldn't worry about. It's just that Emily Oster comes to slightly different conclusions.
(SOUNDBITE OF SONG, "BABY I LOVE YOU")
RAMONES: (Singing) Baby, I love you. Come on, baby. Baby, I love you. Ooh-wee (ph), baby. Baby, I love, I love only you.
JOFFE-WALT: I am Chana Joffe-Walt.
BLUMBERG: And I am Alex Blumberg. Thanks for listening.
(SOUNDBITE OF RAMONES SONG, "BABY I LOVE YOU")
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