Ectopic pregnancy is not more likely following fresh vs frozen embryo transfer

To determine if the risk of ectopic pregnancy is greater following frozen vs fresh embryo transfer (ET).

Retrospective review of pregnancy outcome from January 1, 1997 to November 30, 2003. Cryopreservation was used as a simple freezing method and one-step removal of cryoprotectant. The cycles consisted mostly of graduated estradiol and progesterone supplementation.

The ectopic pregnancy rate in 1,445 clinical pregnancies from fresh ET was 2.6% vs 2.0% of 975 clinical pregnancies resulting from frozen ET.

In contrast to the conclusions of two previous studies, the present study evaluating twice as many clinical pregnancies than the two aforementioned studies combined failed to show any greater risk of ectopic pregnancy when transfers were performed on day 3.