Objective: To assess the ectopic pregnancy risk among women who conceived with assisted reproductive technology (ART) procedures.
Methods: The ectopic rate for ART pregnancies was calculated from population-based data of pregnancies conceived with ART in U.S. clinics in 1999-2001. Variation in ectopic risk by patient and ART treatment factors was assessed by using bivariate analyses and multivariable logistic regression.
Results: Of 94,118 ART pregnancies, 2,009 (2.1%) were ectopic. Variation was observed by procedure type. In comparison with the ectopic rate (2.2%) among pregnancies conceived with in vitro fertilization and transcervical transfer of freshly fertilized embryos from the patient's oocytes (fresh, nondonor IVF-ET), the ectopic rate was significantly increased when zygote intrafallopian transfer (ZIFT) was used (3.6%) and significantly decreased when donor oocytes were used (1.4%) or when a gestational surrogate carried the pregnancy (0.9%). Among fresh nondonor IVF-ET procedures, the risk for ectopic pregnancy was increased among women with tubal factor infertility (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.7-2.4; referent group = ART for male factor), endometriosis (OR 1.3, 95% CI 1.0-1.6), and other nontubal female factors of infertility (OR 1.4, 95% CI 1.2-1.6) and decreased among women with a previous live birth (OR 0.6, 95% CI 0.5-0.7). Transfer of embryos with an indication of high implantation potential was associated with a decreased ectopic risk when 2 or fewer embryos were transferred (OR 0.7, 95% CI 0.5-0.9), but not when 3 or more embryos were transferred.
Conclusion: Ectopic risk among ART pregnancies varied according to ART procedure type, reproductive health characteristics of the woman carrying the pregnancy, and estimated embryo implantation potential.
Level of evidence: II-2.