The clinical features and incidence of concurrent intra and extra uterine pregnancies

Concurrent intra and extrauterine pregnancies have always been thought to be rare with a mean annual incidence of 1:30.000. The condition has been reported more frequently in the recent literature. If the incidence is increasing it is a serious development as the condition is often undiagnosed. The paper describes 5 patients with the condition presenting between 1976-1981 an incidence of 1:4000 deliveries. In two of these five patients the intrauterine pregnancy was diagnosed first and the ectopic pregnancy was undiagnosed until much later. The presence of intrauterine pregnancy often leads us to ignore the possibility of a concurrent extrauterine pregnancy. Considering that ectopic pregnancy may still cause maternal death, we believe that the condition has to be considered more often. Certain features may suggest the diagnosis. 1) Lack of vaginal bleeding or uterus larger than 9 week size with a proven ectopic pregnancy. 2) Presence of two corpora lutea at laparoscopy. 3) Ultrasound to diagnose an adnexal mass. 4) Failure of serum hCG to return to normal after abortion. The text also discusses the natural history of the condition and the higher incidence expected in the future with the wider use of ovulation inducing agents.