Of all the pregnancy taboos I’ve heard in my 34 weeks of this surreal, at times ache-inducing, but ultimately incredible state, caffeine has caused me the greatest chagrin. Strangers in line at Coffee Central offered helpfully: “You’ll get decaf, of course.” My four-year-old nephew looked at a cup of tea in my hands, his brow furrowed with reproach: “But you’re pregnant!” My obstetrician-gynecologist drew the line at one or two coffees a day. My personal literature review allowed me a more nuanced approach in which I count milligrams of caffeine per day, adjusting for my hydration level and professional obligations.
So when a few friends forwarded me an article in The Wall Street Journal by University of Chicago economist Emily Oster that purported to dispel myths of pregnancy and set the record straight on such divisive beverage choices, I was intrigued. I’ve since read her book on the subject and have come away with mixed feelings.
I share some of Oster’s frustrations with the conventional wisdom on what women can and cannot do when pregnant, especially when such statements aren’t supported by medical evidence. I applaud her instinct to dig up the primary sources for the answers.
But putting aside some legitimate concerns raised by others about how Oster interprets the data, I found the premise of her book unsettling. “Expecting Better presents the hard facts and real-world-advice you’ll never get at the doctor’s office or in the existing literature,” promises the dust jacket blurb, and the pages inside perpetuate the notion that doctors only deal in sharp cut-offs and sometimes arbitrary black and white rules.
Obstetrics is a field famously wanting for hard evidence because it is ethically challenging to subject pregnant women to the gold standard of studies: a randomized controlled trial in which you can truly nail down cause and effect (eg. drinking an additional x amount of milk leads to having a baby that is y inches taller.) But doctors should, and the good ones do, understand the evidence that is available. More importantly, they are in a unique, and critical, position to frame it for their patients. I concede that this doesn’t happen often enough, for a variety of reasons. Prenatal visits are incredibly short. Some of the nuances of the studies likely become blurred over time and practice. That’s something we need to work on – by staying on top of the latest studies and by using tools like decision aids to promote shared decision-making.
At the same time, doctors aren’t just in the business of summarizing studies, we are also charged with tailoring that evidence to individual patients and promoting public health. In these capacities, it may be appropriate in some cases to skip exhaustive detail (many patients don’t want or are comfortable with this). There are other factors we consider when offering pre-natal testing besides a patient’s risk tolerance, like health care costs. And with the socially charged public health issue of drinking alcohol during pregnancy, a hard line may be the most responsible one for doctors to take initially, though patients deserve a more refined answer when they ask (Oster has gotten a lot of heat for her liberal stance on drinking alcohol).
So, what about that caffeine? I found Oster’s literature review helpful, particularly the interesting (though not novel) observation that correlations between early coffee drinking and miscarriage are confounded by the fact that women who are nauseated are both more likely to have healthy pregnancies (which may correlate with higher estrogen levels) and less likely to stomach coffee. I don’t, however, share Oster’s practice of drinking four cups a day, in part because I would sleep even less than I already do and in part because more recent studies give me pause. I’m sticking to my careful caffeine dosing method and hoping for the best.