Interstitial pregnancy: results generated from the Society of Reproductive Surgeons Registry

To summarize management of interstitial pregnancy and its outcome among 32 reported cases in the world.

From 1999 to 2002, 32 cases of interstitial pregnancy were reported to the registry of the Society of Reproductive Surgeons. The participants completed a five-page questionnaire regarding when and how diagnosis was made, the characteristics of the pregnancy, treatment modalities, and subsequent reproductive outcome.

History of ipsilateral salpingectomy was encountered in 37.5% of patients, and the diagnosis was made by ultrasound in 71.4% of the patients. Eight women were treated with methotrexate either systemically (n = 4), locally under ultrasound guidance (n = 2), or under laparoscopic guidance (n = 2). Eleven patients were treated by laparoscopy and 13 by laparotomy. Three patients failed systemic methotrexate treatment and subsequently required surgery. Persistently elevated serum beta human chorionic gonadotropin levels were found in one patient after laparoscopic cornual excision, and she was successfully treated with methotrexate. Fourteen cases (43.7%) of rupture of interstitial pregnancy were found. This included five cases (15.6%) of heterotopic pregnancy; all were the results of in vitro fertilization, and all ruptured at the time of diagnosis. Subsequent pregnancy was achieved in ten patients. No uterine rupture was encountered during pregnancy or labor.

Ipsilateral salpingectomy, previous ectopic pregnancy, and in vitro fertilization are predisposing factors for interstitial pregnancy. Contrary to previous belief, rupture of interstitial pregnancy occurs relatively early in pregnancy. In selected patients, laparoscopic cornual excision is a viable treatment option.