Ectopic pregnancy risk with assisted reproductive technology procedures.

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.