Cesarean scar ectopic pregnancies: etiology, diagnosis, and management

To clarify the appropriate way to diagnose and treat an ectopic pregnancy in the uterine scar of a prior cesarean delivery.

Articles written in English that were published from January 1966 to August 2005 and quoted in the computerized database MEDLINE/PubMed retrieved by using the words "cesarean section," "cesarean delivery," "cesarean section scar pregnancy," and "ectopic pregnancy." Additional articles were obtained from reference lists of pertinent case reports and reviews.

Fifty-nine articles that met the inclusion criteria provided data on the clinical presentation, diagnosis, and treatment modalities of 112 cases of cesarean delivery scar pregnancies.

Review of the 112 cases revealed a considerable increase in the incidence of this condition over the last decade, with a current range of 1:1,800 to 1:2,216 normal pregnancies. More than half (52%) of the reported cases had only one prior cesarean delivery. The mean gestational age was 7.5 +/- 2.5 weeks, and the most frequent symptom was painless vaginal bleeding. Endovaginal ultrasonography was the diagnostic method in most cases, with a sensitivity of 84.6% (95% confidence interval 0.763-0.905). Expectant management of 6 patients resulted in uterine rupture that required hysterectomy in 3 patients. Dilation and curettage was associated with severe maternal morbidity. Wedge resection and repair of the implantation site via laparotomy or laparoscopy were successful in 11 of 12 patients. Simultaneous administration of systemic and intragestational methotrexate to 5 women, all with beta-hCG exceeding 10,000 milli-International Units/mL required no further treatment.

Surgical treatment or combined systemic and intragestational methotrexate were both successful in the management of cesarean delivery scar pregnancy. Because subsequent pregnancies may be complicated by uterine rupture, the uterine scar should be evaluated before, as well as during, these pregnancies.