Dr. Ghislain Hardy, a third year resident in obstetrics and gynecology at McGill, and his team did a chart review of 17,916 women who delivered at Royal Victoria Hospital, McGill’s teaching hospital. Of their sample, 13% had obtained one abortion and 5% had procured two or more.

Dr. Hardy’s team found that women with one past abortion were 45% more likely to give birth before 32 weeks, 71% more likely to do so at less than 28 weeks, and more than 50% more likely at less than 26 weeks. They noted that the link was even greater where the woman had more than one abortion.

He presented the paper, entitled “Early Preterm Birth and Adverse Perinatal Outcomes in Women With a History of Induced Abortions,” at the 58th Annual Clinical Meeting of the American College of Obstetricians and Gynecologists, held from May 15-19.

“Preterm birth is a major concern in our health-care system today. It is the most important cause of neonatal morbidity,” Dr. Hardy explained in his presentation, according to the Canadian Health Network. A study of the issue is important, he noted, because “an association between therapeutic abortion and prematurity has resurfaced in recent years.”

The link between abortion and subsequent premature delivery has been confirmed by a growing body of independent studies on the issue. Most significantly, in February 2009 a German team who evaluated over two million pregnancies between 1995 and 2000, found that the risk of very premature birth is increased by 30% after one abortion, and by 90% after more than one.

Dr. Hardy explained that abortion could lead to greater cervical sensitivity that might result in a greater proclivity towards premature delivery.