Welcome to Impact Factor, your weekly commentary on a breaking medical study. I’m Dr F. Perry Wilson.
This week, we are not going to put to rest the abortion debate in the United States, but we will put to rest one thread of argument that has never been well supported by data. The argument is that abortion poses significant health risks to the mother.
According to the most rigorous study yet of the long-term physical effects of abortion versus childbirth, appearing in the Annals of Internal Medicine, that particular line of argument should be discarded from the broader national dialogue.
Let’s take a look.
There’s something special about the design of the Turnaway Study. Rather than comparing women who received an abortion to all other women, as many observational studies do, it compared women who sought and received an abortion to women who were denied an abortion, typically on the basis of later gestational age.
For example, if a clinic had a gestational age limit of 22 weeks, the study would compare women in the clinic who received an abortion just under that limit (20-22 weeks) with women who were just over that limit (22-23 weeks) and were thus denied an abortion. This is not a perfect control group, but it’s about the best we could hope for, and the baseline characteristics of the women in these two groups were quite similar.
The women were followed for 5 years to allow the researchers, led by Dr Lauren Ralph of the University of California San Francisco, to evaluate their long-term physical health outcomes. Why the focus on physical health? Here’s Dr Ralph:
So her team set out to examine the evidence. By every metric, the women who received an abortion had similar physical health outcomes to those who were refused one. For a few relevant outcomes, like self-rated health, women who received an abortion fared better.
Prior studies in the same cohort examining short-term physical outcomes and short- and long-term mental health showed a similar pattern. Women who received an abortion fared the same or better than women who were denied one.
In other words, abortion is a medical procedure that, like all procedures, has risks, but childbirth seems to have greater risks.
In fact, a startling piece of data in this study is that two of the 163 women who were denied an abortion died from complications of pregnancy or childbirth.
Will this study move the needle on the national debate? Here’s Dr Ralph again:
As I said up front, we never had good data to support the argument that abortion causes long-term physical harm to women. And though this has never been the primary argument against abortion, we now have good-quality data to suggest that no such harm exists.