Photo: Compassionate Eye Foundation

Everyone knows the rules of pregnancy. Alcohol is a no-no. Coffee is out, too, and forget about sushi or delicious soft-boiled eggs. But a new book from an American economist (yep, really) might spell the end of this traditional pregnancy “knowledge.”

Professor Emily Oster’s book, Expecting Better: Why the Conventional Pregnancy Wisdom is Wrong – and What You Really Need to Know, came out last week and it explains how many of the traditional rules of pregnancy are wrong, or based on shonky science. But overwhelmingly, the book is about making autonomous decisions about and during your pregnancy based on what you know, and how it may affect you. It’s not a pregnancy guide. Actually, it’s more of a feminist pregnancy reader.

Oster has a vested interest in the topic. When she fell pregnant, she noted that in many ways, it felt like being a child again. “There was always someone telling you what to do,” she says. But what were the reasons behind all of these rules, she wondered. For example, Oster wanted to continue having an occasional drink (as well as coffee). She wanted to know why doctors recommended against it, and what the potential risks and benefits were.

An economist, Oster was used to making decisions for a living, and so often applied these skills to her personal life. Pregnancy was no exception. After looking at the studies, Oster found that most only correlated alcohol with lower IQs – they did not state that alcohol was the cause of this. The women studied who did drink during pregnancy also tended to be from lower socio-economic areas, more likely to be single mothers and less educated than women who abstained. In some studies, the drinkers also took cocaine while pregnant (whereas the non-drinkers didn’t).


For better, more randomised studies, Oster went to Europe, where alcohol during pregnancy isn’t so frowned upon. Because the women in those studies were from more varied demographics, Oster was able to get a better picture. And she discovered that light drinking (up to two glasses per week during the first trimester, and up to a glass a day thereon) made no difference to the foetus. Oster found that the problem of correlation vs causation is at the heart of many so-called pregnancy truths, like coffee drinking and exercise increasing the chances of miscarriage.

Of course, there are benefits to universal health rules. From a public health perspective, it is easier and perhaps better to say no to alcohol, for example, during pregnancy, because there is a risk that if doctors do say it’s OK, some women will continue to binge drink, which we know is a risk to the foetus. But Oster’s appeal is to educated, autonomous women to “lean in” to their pregnancies the same way that Sheryl Sandberg asks us to “lean in” to our careers. “When it comes to pregnancy,” Oster says, “women often passively accept the conventional wisdom.”

There’s a good reason for this – most of us are not medical experts and we are concerned for the health of our babies. However, as Oster points out, there are benefits to asking more questions, looking for the real facts and making decisions ourselves, based on what we know and how it might affect us.

Unsurprisingly, Oster and her book are copping a lot of flak for spruiking “controversial” ideas. Much like having a “natural” birth (that is, drug-free and vaginal) and exclusively breastfeeding, following all the pregnancy rules has become shorthand for being a good mother.

The rules are not just medical recommendations, either – we hear them from our family, friends and even strangers. When I was pregnant, I felt comfortable having the occasional glass of wine – but I was decidedly uncomfortable with the aunt who repeatedly whisked away my wine glass at family functions. When I asked for it back, her husband told me that I could have “just one.” Neither of these people are medical experts, and yet they felt confident giving me directives about my body and health. During pregnancy, allowing ourselves a little leeway is seen as naughty at best and complete failure at worst.

But we should feel empowered to modify the “rules”. Pregnancy is not a “one-size-fits-all” affair, says Oster, so we should (and absolutely can) think about the decisions we make. Nobody is suggesting you take up smack during your first trimester or even smoke a cigarette. There are some things that are unequivocally bad for your health, and naturally, your baby’s. So if you think it’s too big a risk to drink coffee during pregnancy, don’t do it. If, having seen the evidence, you decide you’d like a grande latte, that’s OK too. She wants us to arm ourselves with knowledge and weigh up our decisions from there. For Oster, knowing “the numbers” helped her relax during pregnancy, knowing she wasn’t harming her baby by ordering a piccolo (the caffeinated or alcoholic kind)