Menus Subscribe Search

Five Studies

fob-five-studies

(PHOTO: BEN WELSH/CORBIS)

What to Accept When You’re Expecting

• August 15, 2013 • 6:00 AM

(PHOTO: BEN WELSH/CORBIS)

Do we need to be scaring pregnant women so much?

If someone told you to alter your daily behavior, the first question you’d probably ask would be “Why?” And if you were told your actions were “risky,” you’d likely wonder “How risky?” Driving, cycling, staying home—everything we do carries some risk. The usual question is, how much risk is acceptable? Yet there are a few arenas where we tolerate zero risk, demanding lifestyle changes first and asking questions later. As anyone who’s flown since 9/11 knows, national security is chief on that list. And so is pregnancy. Pregnant women give up foods, beverages, and behaviors because they’re told, “You can never be too careful.” Emily Oster, bless her, says, “Oh, yes you can.”

Oster, a University of Chicago economist, was prompted by the frustrations of her own pregnancy to run the numbers on the standard prohibitions. In her new book, Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong—and What You Really Need to Know, Oster aims a welcome arsenal of data at a subject usually treated with hysteria. Although the book’s tone can get oddly glib and some of the myths she debunks were never really bunked in the first place (yes, you can have sex while pregnant), on the whole, Oster’s book is surprising and useful. Oster makes a persuasive case that much of what pregnant women are told today is simply wrong, and that many of those “risky” behaviors aren’t so risky after all.

1

You can drink coffee (a lot)

Bump, a Brooklyn maternity store, advertises itself with the slogan: “Give up wine, coffee, sushi—not fashion.” Whether or not one ever had fashion, coffee is definitely on the “not recommended” list these days. Certain doctors and the Mayo Clinic Guide to a Healthy Pregnancy recommend avoiding coffee, while others suggest drinking it only “in moderation.” But for people (like Oster) who routinely consume three to four cups per day, are there persuasive reasons to stop? Not according to some of the data. The presumed risk for coffee drinkers is a higher rate of miscarriage, but a 2008 study in the journal Epidemiology found that those who drink up to three cups per day have the same risk as light coffee drinkers and abstainers.

—“Caffeine and Miscarriage Risk,” Epidemiology 19, no. 1, by D. A. Savitz et al, January 2008

2

You can drink booze (a little)

We know the effects of fetal alcohol syndrome (caused by heavy drinking during pregnancy) are real. What’s harder to quantify is the effect of light drinking. The studies on light drinking (up to a drink a day) during pregnancy seem to have contradictory outcomes, but Oster sifts through the data to show that not all studies are created equal. One of her favorites, from researchers in Australia, looked at a large group of women and included long-term follow-ups on their children. Children of light drinkers turned out to have slightly higher IQs than those who abstained completely—not enough higher to be statistically significant but enough to put to bed those fears that a small glass of wine could be harming your unborn child. On the other hand, Oster dismisses a 2001 U.S. study used to justify the prohibition on light drinking because she thinks it failed to adequately account for the fact that many of the study’s drinkers were also doing cocaine while pregnant. Don’t do cocaine.

—“Prenatal Alcohol Exposure and Attention, Learning, and Intellectual Ability at 14 Years: A Prospective Longitudinal Study,” Early Human Development 83, no. 2, by F. V. O’Callaghan et al, February 2007

3

Prenatal tests aren’t so scary

Prenatal tests are stressful. They involve imagining a whole array of potential disabilities and trying to determine what your response would be to each. On top of that, the tests themselves can carry risks, and balancing the risk of an undetected condition against the risk of a test can be a conundrum. But just how risky are invasive tests? The statistics commonly cited are that one out of every 200 amniocentesis tests and one out of every 100 CVS (chorionic villus sampling) tests result in an accidental miscarriage. That’s a pretty risky risk. But Oster reports that those stats are 30 years out of date, coming from a time when these procedures were much newer. With years of practice and new technologies, doctors have gotten better at performing the tests, and the risk rates have gone down accordingly. Using a group of recent studies (some of which show performing the tests as no riskier than not performing them), Oster comes up with an estimate that amniocentesis and CVS each have a miscarriage risk of between 1 in 600 and 1 in 800.

—“Evaluating the Rate and Risk Factors for Fetal Loss After Chorionic Villus Sampling,” Obstetrics & Gynecology 112, no. 4, by A. O. Odibo et al, October 2008

4

Get out of bed

As many as 20 percent of pregnant women will be on bed rest at some point during their pregnancies, so there must be some good reason for it, right? Doesn’t look that way. Oster couldn’t find a single study suggesting that bed rest improves outcomes for babies. One study in particular found that bed rest neither prevents preterm birth nor increases birth weight—its supposed primary benefits. So if bed rest doesn’t help, at least it can’t hurt, right? Wrong. Bed rest’s risks range from the practical (there’s a real economic drag inherent in removing yourself from normal wage-earning activities and having to hire someone to fill in at home) to the physical (bed rest could cause serious health problems, including bone loss, muscle atrophy, and blood clots). If a treatment has only downside and no known upside (except catching up on Mad Men), it seems reasonable to assume that the treatment isn’t really a treatment at all.

—“Lack of Evidence for Prescription of Antepartum Bed Rest,” Expert Review of Obstetrics & Gynecology 6, no. 4, by J. A. Maloni, July 2011

5

Keep your cat, but buy gardening gloves

Most pregnancy books have a quick throwaway line about cats, warning pregnant women away from the litter box. Cats that eat raw meat can have the toxoplasmosis parasite, which is transmitted through feces, so the standard strategy is to ask your partner to change the box. Some women even go so far as to get rid of their cats during pregnancy. But is it worth finding a litter-sitter? As it turns out, no. A study of pregnant women in Europe found that cat ownership had no bearing on toxoplasmosis exposure. Cats are only capable of transmitting the disease when they are first exposed to it. If you have an outdoor cat, odds are he or she was exposed long ago and no longer poses a risk. Based on the European study, Oster recommends avoiding acquiring kittens mid-pregnancy (they’re more likely to get the disease for the first time). She also advises taking extra care in the garden because the study did find a strong association between toxoplasmosis and working with soil. Plants are apparently far riskier than Felix.

—“Sources of Toxoplasma Infection in Pregnant Women: European Multicentre Case-Control Study,” BMJ 321, no. 7254, by A. J. C. Cook et al, July 2000

Dorothy Fortenberry
Dorothy Fortenberry is a playwright who lives in Los Angeles.

More From Dorothy Fortenberry

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

September 2 • 4:00 PM

Professors’ Pet Peeves

Ten things to avoid in your classrooms this year.


September 2 • 2:00 PM

Music Lessons Enhance Brain Function in Disadvantaged Kids

Children from poor neighborhoods in Los Angeles who took regular music lessons for two years were able to distinguish similar speech sounds faster than their peers.


September 2 • 12:00 PM

California Passes a Bill to Protect Workers in the Rapidly Growing Temp Staffing Industry

The bill will hold companies accountable for labor abuses by temp agencies and subcontractors they use.


September 2 • 10:00 AM

SWAT Pranks and SWAT Mistakes

The proliferation of risky police raids over the decades.


September 2 • 9:12 AM

Conference Call: The Graphic Novel


September 2 • 8:00 AM

Why We’re Not Holding State Legislators Accountable

The way we vote means that the political fortunes of state legislators hinge on events outside of their state and their control.


September 2 • 7:00 AM

When Men Who Abstain From Premarital Sex Get Married

Young men who take abstinence pledges have trouble adjusting to sexual norms when they become husbands.


September 2 • 6:00 AM

The Rise of Biblical Counseling

For millions of Christians, biblical counselors have replaced psychologists. Some think it’s time to reverse course.


September 2 • 5:12 AM

No Innovation Without Migration

People bring their ideas with them when they move from place to place.


September 2 • 4:00 AM

Why Middle School Doesn’t Have to Suck

Some people suspect the troubles of middle school are a matter of age. Middle schoolers, they think, are simply too moody, pimply, and cliquish to be easily educable. But these five studies might convince you otherwise.


September 2 • 3:13 AM

Coming Soon: When Robots Lie


September 2 • 2:00 AM

Introducing the New Issue of ‘Pacific Standard’

The science of self-control, the rise of biblical counseling, why middle school doesn’t have to suck, and more in our September/October 2014 print issue.


September 1 • 1:00 PM

Television and Overeating: What We Watch Matters

New research finds fast-moving programming leads to mindless overeating.



September 1 • 6:00 AM

Why Someone Named Monty Iceman Sold Doogie Howser’s Estate

How unusual names, under certain circumstances, can lead to success.



August 29 • 4:00 PM

The Hidden Costs of Tobacco Debt

Even when taxpayers aren’t explicitly on the hook, tobacco bonds can cost states and local governments money. Here’s how.


August 29 • 2:00 PM

Why Don’t Men and Women Wear the Same Gender-Neutral Bathing Suits?

They used to in the 1920s.


August 29 • 11:48 AM

Your Brain Decides Whether to Trust Someone in Milliseconds

We can determine trustworthiness even when we’re only subliminally aware of the other person.


August 29 • 10:00 AM

True Darwinism Is All About Chance

Though the rich sometimes forget, Darwin knew that nature frequently rolls the dice.


August 29 • 8:00 AM

Why Our Molecular Make-Up Can’t Explain Who We Are

Our genes only tell a portion of the story.


August 29 • 6:00 AM

Strange Situations: Attachment Theory and Sexual Assault on College Campuses

When college women leave home, does attachment behavior make them more vulnerable to campus rape?


August 29 • 4:00 AM

Forgive Your Philandering Partner—and Pay the Price

New research finds people who forgive an unfaithful romantic partner are considered weaker and less competent than those who ended the relationship.


August 28 • 4:00 PM

Some Natural-Looking Zoo Exhibits May Be Even Worse Than the Old Concrete Ones

They’re often designed for you, the paying visitor, and not the animals who have to inhabit them.


August 28 • 2:00 PM

What I Learned From Debating Science With Trolls

“Don’t feed the trolls” is sound advice, but occasionally ignoring it can lead to rewards.


Follow us


Subscribe Now

When Men Who Abstain From Premarital Sex Get Married

Young men who take abstinence pledges have trouble adjusting to sexual norms when they become husbands.

Your Brain Decides Whether to Trust Someone in Milliseconds

We can determine trustworthiness even when we’re only subliminally aware of the other person.

Young, Undocumented, and Invisible

While young migrant workers struggle under poor working conditions, U.S. policy has done little to help.

Education, Interrupted

When it comes to educational access, young Syrian refugees are becoming a “lost generation.”

No, Smartphone-Loss Anxiety Disorder Isn’t Real

But people are anxious about losing their phones, even if they don’t do much to protect them.

The Big One

One third of the United States federal budget for fighting wildfires goes toward one percent of such fires. September/October 2014 big-one-fires-final

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.