Prevent Preterm's summary of the medical literature, written for laypeople and available for free here, included over 100 studies when the campaign launched. Since then, the evidence that abortion is a risk factor for preterm birth in later pregnancies has only grown.
The latest study was published in the May 2016 issue of the American Journal of Obstetrics and Gynecology. It is a meta-analysis (a.k.a. a "study of studies") encompassing over a million women. The majority of the 36 studies analyzed involved women who had obtained abortions; a handful involved women who suffered miscarriages and subsequently required surgical procedures which, like common abortion methods, forcibly open the cervix.
The result, consistent with the existing body of research, is that abortion and similar procedures are associated with an increased risk of premature birth in subsequent pregnancies. The finding was statistically significant.
The authors recommend non-surgical (medical) abortion as a safer alternative, but on that point, the science is less settled. A Chinese study published in the Archives of Gynaecology and Obstetrics in September of 2011 (Vol. 284 no.3 pp.579-586) found an increased risk of premature birth following medical abortions, too. But to date, the bulk of the published literature has focused on surgical methods. More research is needed. In the meantime, women seeking abortion of any kind deserve no less than full informed consent.
Guttmacher Institute studies concerning the reasons that women abort indicate that most women who have abortions have not yet completed their childbearing. Women report feeling unprepared for parenthood at the time of the abortion—typically for financial reasons—but being open to parenthood in the future. Some even report getting an abortion out of a desire to set up an ideal situation in which to parent sons and daughters not yet conceived.
These statements show a tragic lack of awareness of abortion's long-term consequences. A child born preterm may face lifelong health problems. And ironically, those problems are often expensive, creating a financial burden on the family—precisely the outcome the mother sought to avoid by having an abortion.
You can help by talking to your friends about the latest meta-analysis and by sharing Prevent Preterm graphics on social media.