Second trimester dilation and evacuation: a risk factor for preterm birth?

To evaluate whether second trimester pregnancy termination with dilation and evacuation (D&E) vs induction of labor (IOL) affects subsequent risk of preterm birth.

Our cohort was a retrospective cohort of women undergoing second trimester pregnancy termination for fetal anomalies, fetal death or previable premature rupture of membranes. We analyzed the rates of spontaneous delivery <37 weeks in the first pregnancy following the termination. We also compared preterm birth rates in our cohort with national averages and analyzed by the total number of prior procedures.

There were 173 women in our cohort. Women who had undergone a D&E (n=130) were less likely to have a subsequent preterm birth (6.9 vs 30.2%; P<0.01). This held true for a low risk subset without obstetric risk factors. There was no statistical difference in preterm birth rates for women who had undergone a D&E as compared with national averages, nor between the rates of preterm birth for women with 0, 1, 2 or 3 or more prior first or second trimester procedures.

We did not find that D&E was a risk factor for preterm delivery when compared with women with a prior IOL or national rates.