Comparison of Pregnancy, Implantation, and Multiple Gestation Rates for Day 3 Versus Day 5 Embryo Transfers

Purpose: To compare pregnancy, implantation, and multiple gestation rates resulting from day 3 and day 5 embryo transfers after in vitro fertilization emphasizing a subset of patients who met criteria for day 5 transfer but elected to undergo day 3 transfer. Method: A retrospective analysis of day 3 and day 5 embryo transfers from January 2001 to June 2002 were evaluated in a community teaching hospital setting. A total of 331 patients ≤40 years old were included. Using Student's t test, ²χtest, and Fisher's exact test, we compared the pregnancy, implantation, and multiple gestation rates. Results: Pregnancy, implantation, and multiple gestation rates were not significantly different between the subgroup who met criteria for day 5 embryo transfer but elected day 3 transfer. There was no significant difference between similar parameters in the overall comparison of day 3 versus day 5 embryo transfers. Conclusions: Blastocyst transfers have similar multiple gestation rates, pregnancy rates, and implantation rates when compared to day 3 embryo transfers.