Failed first trimester pregnancy termination: uterine anomaly as etiologic factor.

Failure of first trimester pregnancy termination is an uncommon, although potentially serious complication of attempted therapeutic abortion. We report our experience in four patients with unsuspected congenital uterine anomalies in whom attempted pregnancy termination procedures failed to completely ablate the products of conception. When dilatation and curettage fails to produce embryonic tissue, sonography is indicated to exclude ectopic gestation or uterine anomaly. In patients who are known to have anomalous uteri, intraoperative real-time guidance may increase the success of pregnancy termination procedures and decrease the incidence of retained products of conception.