Trends in gestational age at time of surgical abortion for fetal aneuploidy and structural abnormalities

Screening for fetal aneuploidy has evolved over the past 2 decades. Whether these advances impact gestational age at abortion has received little study.

We sought to describe trends in the gestational age at the time of abortion by fetal diagnosis over an 11-year study period. We hypothesized that gestational age at time of abortion would decrease for fetal aneuploidy but remain unchanged for structural abnormalities.

We conducted a retrospective case series of all women undergoing surgical abortion for fetal aneuploidy or structural abnormalities up to 24 weeks' gestation from 2004 through 2014 in a hospital operating room setting at a single, urban medical center. We excluded labor induction abortions (<1% of abortions at our medical center) and suction aspirations performed in the office practice. We performed suction aspiration up to 14 weeks and dilation and evacuation after that gestational age. We describe the median gestational age at abortion by fetal indication and year.

For women undergoing abortion for fetal aneuploidy (n = 392), the median gestational age at time of abortion decreased from 19.0 weeks (interquartile range 18.0-21.0) in 2004 to 14.0 weeks (interquartile range 13.0-17.0) in 2014 (Kruskal-Wallis P < .0001). For women undergoing abortion for fetal structural abnormalities (n = 586), the median gestational age was ≥20 weeks for each year during the study interval (P = .1). As gestational age decreased in the fetal aneuploidy group, fewer women underwent dilation and evacuation and more became eligible for suction aspiration (<14 weeks). In 2004, >90% of women underwent dilation and evacuation for either indication. By 2014, 31% of women with fetal aneuploidy were eligible for suction aspiration compared to 11% of those with structural anomalies.

Gestational age at the time of abortion for fetal aneuploidy decreased substantially from 2004 through 2014; earlier abortion is safer for women. In contrast, women seeking abortion for fetal structural abnormalities did not experience a change in timing. Legislation restricting gestational age at the time of abortion could disproportionately affect women with fetal structural abnormalities.