Q-and-A with Emily Oster on Modern Pregnancy Guidelines

When economist Emily Oster got pregnant and wasn’t receiving answers from her doctors that seemed grounded in fact, she took matters into her own hands. Now you can benefit from her findings—and make personal, informed decisions about everything from having sushi for dinner to drinking a glass of wine. Read more about rewritten pregnancy guidelines in this Q-and-A with Emily Oster.

Finding out you’re pregnant is a joyous occasion filled with great hope and anticipation. But the next moments are often more sobering as you realize the enormity of the task ahead (growing a human being from start to finish!). Of course you plan to follow doctor’s orders and bear the healthiest baby possible, but what if the advice seems contradictory—or even random?

Emily Oster experienced this conflict when she became pregnant with her first child, Penelope, now 2. But rather than blindly follow along, Oster, who has a Ph.D. in economics from Harvard University, put her training to work, sifting the data to separate worthy rules from the outdated ones. “Expecting Better: How To Fight The Pregnancy Establishment With Facts” (Penguin) is the result.

“Actually getting the numbers behind some of the current recommendations led me to a more relaxed place. I found it enormously reassuring to know why.”

Here, some of her more revealing discoveries.

Have you talked about your approach to decision-making based on data with ob-gyns?

I worked very closely with a medical editor and discussed these issues at length. I’m finding that medicine is actually moving much more toward evidence-based decision-making, which is exactly what I’m trying to do in my book. And in certain cases, where common practice is more outdated than the research, there was definite agreement. For example, putting a woman on bed rest toward the end of her pregnancy in order to stave off a premature birth continues to be recommended for almost 20 percent of women, yet most research shows it has limited benefits. But because bed rest has been in practice for so long, I suspect it’s a hard habit to break.

How should moms without your training in economics go about making their own decisions?

Even if you don’t have experience with statistical evidence or a background in decision theory, you can still approach your pregnancy by weighing the pros and cons for each issue. In most cases, you can boil down the decision so it’s easier to think about. This doesn’t mean that the answer is an obvious one (for example, amnio is a rather complicated issue), but at least you’ll have a chance to think carefully and make a good decision when you have to.

Women today seem to worry about putting on the pounds in pregnancy, but you’ve written that they should instead be careful not to gain too little. Why is that?

In general, I would argue that most women should relax about their weight—you won’t explode if you gain a couple more pounds! The only very significant impact on weight gain is your baby’s size (more weight, bigger baby; less weight, smaller baby). And since bigger babies tend to be lower risk than smaller ones, this evidence suggests that moms may want to err on the side of a bit more weight, rather than less.

Wine! Women in many parts of the world drink it during pregnancy, but in the U.S., it’s verboten. Why are doctors here so against it?

I examined a series of studies in the book and ultimately decided that the evidence is pretty overwhelming that having an occasional drink after the first trimester, even one a day, is fine (this is in line with recommendations in some other countries). Doctors, of course, are often concerned with issues outside the evidence. For example, if you tell a woman she can have one drink, she may think another (or three) is okay, too.

But wouldn’t a pregnant woman drinking a glass of wine be the target of sneers or nasty comments? How do you suggest she handle this?

I had an occasional glass of wine when I was pregnant with Penelope. I personally approach comments from strangers by endlessly detailing all of the medical literature until their eyes glaze over and they are sorry they even asked. But frankly, telling people it’s none of their business works just as well.

What is it about gardening that could be risky when pregnant?

I learned about this danger when I was trying to determine whether it was okay to clean out the cat’s litter box. Women have long been told to avoid this chore because of toxoplasmosis, an infection from a fecal parasite that can cause birth defects. But as it turns out, this is overblown for most cat owners: you’d have to be feeding your cat a lot of raw meat and she’d have to have never been exposed to the parasite. Many more people actually get toxoplasmosis from the soil in their gardens (though it’s still rare).

If you have a second child, will you do anything differently during your pregnancy?

I’ll have the CVS test (chorionic villus sampling) rather than the standard prenatal screening because I’ll have aged since my first pregnancy. And I think I’ll eat some sushi! The concern with it—as with many other foods—is that you might get stomach flu. In the end, however, the risk is the same as it always is (there’s no added danger when you’re pregnant).

Jennifer Kelly Geddes is a freelance writer whose work has appeared in Parenting, Time Out NY Kids, and Babytalk. She lives with her family in Harlem.