Human chorionic gonadotropin levels after blastocyst transfer are highly predictive of pregnancy outcome

Objective: To determine the predictive value(s) of beta -hCG serum levels f or pregnancy outcome following blastocyst transfer. Design: Retrospective review. Setting: University-based assisted reproductive technology (ART) program. Patients: All ART patients enrolled from January 1998 to December 1999. Int ervention(s): None. Main Outcome Measure(s): beta -hCG serum levels and pregnancy outcomes. Result(s): Of the 836 ART cycles initiated, 608 embryo transfers met study criteria and were assigned to one of two groups: 248 day 5 blastocyst trans fers or 360 day 3 embryo transfers. In the day 5 blastocyst. group, 147 pre gnancies occurred (59.2%), and day 3 transfers resulted in 165 pregnancies (45.8%). For day 3 and day 5 transfers, mean values of beta -hCG on day 16 post-retrieval of spontaneous abortions were lower than ongoing pregnancies (P < .05). A beta -hCG value on day 16 of > 300 mIU/mL predicted an ongoin g pregnancy for day 5 transfer group in 97% of pregnancies compared with 92 % for day 3 embryo transfers. A multiple gestation was observed in 70% of p regnancies with a beta -hCG level > 400 mIU/ml in the day 5 group compared with 63% for the day 3 group. The incidence of higher-order multiple gestat ions was significantly tower in the day 5 blastocyst group (P < 05). Conclusion(s): beta -hCG serum levels on day 16 post-retrieval were highly predictive of pregnancy outcome after a blastocyst transfer. (C) 2001 by Am erican Society for Reproductive Medicine.