Women who have had an abortion appear to have an increased risk of having a very preterm infant in future pregnancies. Researchers from the Hopital de Bicetre, Le Kremlin Bicetre, France, note that there has been much debate on the effect of induced abortions on subsequent pregnancies. Studies have, however, failed to reach clear conclusions. To investigate further, they examined the records for nearly 2,000 very preterm infants, 276 moderately preterm infants and a comparison group of 618 full-term infants. Very preterm infants were defined as those born after only 22 to 33 weeks of gestation. Women with a history of induced abortion had a 50-percent higher risk of having a very preterm delivery than women who had not had an abortion. Furthermore, the risk of delivering an infant at less than 28 weeks was 70% higher in this group. No association was found between induced abortion and very preterm delivery due to high blood pressure. A history of induced abortion was, however, associated with an increased risk of premature rupture of the membranes, bleeding not associated with high blood pressure, and unexplained spontaneous preterm labor. The researchers concluded that induced abortion increases the risk of preterm births, particularly extremely preterm deliveries. The findings suggest the need for further research, in particular, to assess the differences in the level of risk according to the technique used for abortion. As using drugs to induce abortion is supposed to reduce the rate of injury to the woman, it would be important to know if this approach also reduces the risk of subsequent preterm delivery, compared with abortions performed surgically.
British Journal of Obstetrics and Gynaecology,
April 2005