Spontaneous uterine cornual rupture at 26 weeks' gestation in an interstitial heterotopic pregnancy following in vitro fertilization.

Interstitial implantation in a heterotopic pregnancy is extremely rare, and despite currently available diagnostic modalities, early identification of an interstitial ectopic pregnancy remains difficult. This report describes a case of spontaneous cornual rupture at 26 weeks' gestation in a woman with diamniotic dichorionic twins that resulted in live births. The patient had previously undergone laparoscopic bilateral salpingectomy, and the pregnancy was conceived with in vitro fertilization. Interstitial implantation in a heterotopic pregnancy can go unrecognized, resulting in increased maternal and infant morbidity and mortality.