Factors affecting fetal loss in induction of ovulation with gonadotropins: increased abortion rates related to hormonal profiles in conceptual cycles.

Thirty-six first-trimester abortions (9.7%), 16 second-trimester abortions (4.3%), 11 ectopic pregnancies (2.9%), and 10 stillbirths (2.7%) occurred in 373 conceptual cycles after gonadotropin induction of ovulation. Fetal wastage was higher in spontaneous pregnancies that occurred before therapy (54.3%, p less than 0.0001) and lower with subsequent spontaneous pregnancies (10.1%, p less than 0.05). Significant risk factors for overall fetal loss during induced ovulation were a continuous rise of estrogen excretion until ovulation (p less than 0.01) and previous abortion (p less than 0.05). For first-trimester abortion, the risk factor was continuous estrogen rise (p less than 0.01); for second-trimester abortion, the risk factors were a low luteal pregnanediol-to-estrogen excretion ratio (p less than 0.002), increased age at conception (p less than 0.02), and high baseline estrogen excretion (p less than 0.05). Multiple pregnancy was not significant. The continuous rising estrogen pattern may serve as a marker of abnormal oocyte maturation. We propose that future studies on infertility treatment should report on pregnancy outcome.