NRL News

Meta-analysis Confirms Abortion’s Connection to Subsequent Preterm Deliveries

by | May 16, 2016

By Randall K. O’Bannon, Ph.D., NRL Director of Education & Research

This analysis appears in the current digital edition of National Right to Life News. Along with all other columns, news stories, and commentaries, Dr. O’Bannon’s story can be read at Please forward this story and the link to the entire issue to your pro-life friends and family.

Preemie49Preterm birth is the leading cause of perinatal mortality in the U.S. and is emotionally and financially costly for families even when it does not prove fatal to the child.

That there has been significant increase in preterm birth in the U.S. in the last forty to fifty years has made researchers curious as to whether there might be a connection to abortion, legalized in 1973. Science Daily (2/3/16) says “One reason to conduct the study is that the incidence of preterm births has been rising, and falling, in parallel to popularity of abortion, the vast majority of which, until late, have been surgical.”

In the last several years, researchers have published multiple studies appearing to demonstrate such a link, but now comes a meta-analysis in a major medical journal which lends strong support to that conclusion. A meta-analysis has more predictive power because it combines the results from multiple studies–in this case 36 studies covering more than one million women.

The study, “Prior uterine evacuation of pregnancy as independent risk factor for preterm birth: a systematic review and meta-analysis,” was published in the May 2016 issue of the American Journal of Obstetrics & Gynecology. The authors are Vincenzo Berghella and Lisa Perriera, two researchers from Thomas Jefferson University (Philadelphia), and Gabriele Saccone, of the University of Naples Federico II in Italy.

Berghella and his colleagues looked at 36 studies covering the cases of 1,047,683 women. They were looking for data that showed what happened in subsequent pregnancies after some form of “uterine evacuation”–that is,  an “induced termination of pregnancy” (surgical or chemical abortion) or the use of some medical means to clear the uterus after a “spontaneous abortion” (miscarriage).

What they found was a significantly higher risk of subsequent preterm birth among women who had surgical abortions or used some surgical means to resolve their miscarriages.

Though both those with surgically treated miscarriages and abortions saw increases, the numbers were much higher for women who had surgical abortions (+ 22.7%) than for those who had surgical treatment for miscarriage (+9.3%). Taken together, those women who had “uterine evacuations” for abortion or miscarriage saw a 14% increase risk of subsequent preterm birth.

Numbers were worse for those women who had D&E abortions (+ 27.9%) or had more than one prior surgical abortion (+172%).

While chemical abortion did not appear to show an increased risk in the three studies authors examined, chemical abortions have their own unique risks: women taking abortion pills [“RU-486” with an accompanying prostaglandin] have bled to death, died from undetected ectopic pregnancies which ruptured, or died of rare infections which were not the subject of this study.

Berghella suggested that the cause in surgical abortion procedures may be the rapid, mechanical dilation of the cervix that is done in order for the abortionist to enter the uterus and remove the child.  The cervix is the lower neck of the uterus that is normally, naturally sealed in pregnancy.

“In normal birth,” Berghella told  Science Daily, “dilation of the cervix occurs slowly over a period of many hours.  Mechanically stretching the cervix however, may result in permanent physical injury to the cervix.”

The resulting scar tissue, Berghella said, could increase the odds of faulty implantation of the placenta in the womb, and could also increase the risk of infectious disease.

In the studies that looked at women with prior surgical abortions, those women had a 5.4% risk of having a subsequent preterm birth as opposed to “controls” who had just a 4.4% risk. (“Controls” are women who’ve had children but had not had a previous “uterine evacuation.”)

To illustrate the significance of these numbers, let’s assume that 80% of the 58.5 million women who have aborted in the United States since 1973 had surgical abortions. Then conservatively estimate that just 50% of those subsequently went on to give birth to just one child. That would mean that this additional 1% risk would be responsible for 234,000 preterm births, enough to populate a sizeable American city.

Given national fertility rates and the likelihood American women will have more than one child, as well as the high rates of repeat abortion, the real figures are probably much higher.

Aborting women were also considerably more likely (+23.7%) to later give birth to babies of low birth weight and infants small for their gestational age (13.3% more likely).

Some of these premature babies will die, especially if born exceptionally early, others will have permanent disabilities.  In 2012, researchers estimated that the hospital costs alone associated with prematurity connected to previous abortions were more than $1.2 billion a year.

This did not include other costs involved with the cerebral palsy, deafness, vision, breathing difficulties, conditions often associated with premature births (see “Growing Evidence Linking Abortion to Subsequent Preterm Birth Being Ignored” in NRL News Today, 6/13/12).

This data makes clear that the mere fact that a mother survives an abortion is not sufficient to call her abortion “safe.” What we see now is that not only does the child she’s carrying lose his or her life, but that abortion may damage her and any future children she may bear.

Categories: Abortion Risks