Risk factors for ectopic pregnancy in assisted reproduction.

OBJECTIVE: To identify risk factors for ectopic pregnancy (EP) after IVF-ET.

DESIGN: Retrospective cohort study.

SETTING: In vitro fertilization clinic at a university hospital.

PATIENT(S): A total of 725 women who conceived after IVF were studied with regard to background factors, indications for IVF, and factors related to the IVF procedure through review of their medical charts. The rate of EP was 4%, corresponding with 29 EPs, of which 2 were heterotopic.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Pregnancy outcome, defined as intrauterine pregnancy or EP. Background factors, indications for IVF, and factors related to the IVF procedure were analyzed for possible correlation with the outcome of EP. Risk factors for EP were identified by logistic regression analysis.

RESULT(S): Tubal factor infertility, various previous abdominal surgeries, previous EP or pelvic infection, presence of a hydrosalpinx or fibroid, and type of transfer catheter used showed a positive correlation with EP as outcome. Logistic regression analysis identified two factors with predictive power: tubal factor infertility and previous myomectomy.

CONCLUSION(S): Tubal factor infertility was the most prominent risk factor for EP after IVF. Previous myomectomy appeared to be another important risk factor, but this is a new finding that needs to be confirmed by further study.