“Being pregnant was a lot like being a child again. There was always someone telling you what to do,” Emily Oster, an economist who teaches microeconomics to first year MBA students at the University of Chicago, wrote in her book Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong – and What You Really Need to Know.

Having made decisions throughout her career based on hard facts and a wealth of data, Oster soon rebelled against the inadequate way in which information was dispensed to her by doctors during insufficiently long medical appointments. She also disliked the ways in which all the information provided to her had been pre-digested and “squished into one-size-fits-all pamphlets,” Oster told The Guardian. Having gone through many studies and available information on her own, Oster now argues that instead of recommendations, pregnant women should learn the actual numbers behind the rules, and with hard data and their own preferences in mind, they can make their own decisions as to whether they want to drink a glass of wine or eat sushi.

“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,” Oster stated in her book. What a mom-to-be really needs is to learn more and worry less.

Old Numbers

One of her most important discoveries was how so many of the rules and regulations were based on out-of-date figures. Once set into (procedural) stone, updates are very slow to filter down into general practice. To explain what she means, she walked The Guardian through her decision-making process regarding amniocentesis.

The procedure involves removing amniotic fluid from the uterus for testing for chromosomal abnormalities. Amniotic fluid, which contains fetal cells as well as various chemicals produced by the baby, is the clear, pale yellow liquid within the amniotic sac that surrounds and protects a baby during pregnancy. A long, thin, and hollow needle is inserted through a pregnant woman’s abdomen, into her uterus and finally into the amniotic sac. The doctor next extracts a small amount of amniotic fluid, which is then analyzed in a lab.

Commonly, it is said that this procedure carries an increased risk of miscarriage and because of that, only women over the age of 35 are recommended to undergo this particular test. At that exact age, the possibility of having a child with a chromosomal disorder is supposed to outweigh the chance of having a miscarriage.

Oster's doctor quoted her risk for miscarriage — one in 200 — and this number immediately gave Oster pause, as it would most expectant mothers. Later, though, she learned her mother had been quoted this very same number... years and years ago in 1985. Suspicious, she discovered and read through a number of studies, crunched her own numbers, and came up with a risk factor that was more like one in 800 (roughly). From here, she began to investigate the cold facts behind each and every warm recommendation doled out to her and soon learned that pregnancy need not be a time of such great anxiety.

“Actually getting the numbers led me to a more relaxed place — a glass of wine every now and then, plenty of coffee, exercise if you want, or not,” wrote Oster. “Economics may not be known as a great stress reliever, but in this case it really is.”