Heterotopic pregnancy: a reevaluation.

Heterotopic pregnancies, or combined intrauterine and extrauterine pregnancies, were first reported in 1708. Traditionally, the rate of occurrence has been thought to be 1:30,000 pregnancies. It has even been said in the recent literature that an intrauterine pregnancy would rule out an ectopic pregnancy. There is good evidence that this is no longer true. The reported incidence in Western Europe and the United States is most probably 1:2600 pregnancies and much higher in certain high-risk groups. Because heterotopic pregnancy is no longer a medical curiosity, it needs to be considered in the differential diagnosis of abdominal pain in pregnancy, in the management of ectopic pregnancy, and in ovulation induction. This report presents a case encountered in a typical family practice. The literature is reviewed, and probable factors responsible for the markedly increased rate (ovulation induction and increase in ectopics in general) are addressed.