Effects of the ovulatory serum concentration of human chorionic gonadotropin on the incidence of ovarian hyperstimulation syndrome and success rates for in vitro fertilization.

OBJECTIVE: To determine whether the serum concentration of hCG on the day after hCG administration (abbreviated throughout this article as [hCG]) is related to the incidence of ovarian hyperstimulation syndrome (OHSS), oocyte recovery per follicle, fertilization, blastulation, embryo transfer, implantation, and clinical pregnancy.
DESIGN: Retrospective study.
SETTING: Private infertility clinic. PATIENT(S): The OHSS study group included 849 non-donor IVF cycles performed between January 1998 and August 2003. The study group for hCG efficacy included 248 nondonor IVF cycles performed between January 2001 and May 2003 with patients younger than 35 years of age. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Occurrence of OHSS, severity of OHSS, [hCG], proportion of follicles yielding oocytes, fertilization rate, blastulation rate, transfer rate, implantation rate, and clinical pregnancy rate. RESULT(S): No significant relationships were observed between [hCG] and the proportion of follicles yielding oocytes, fertilization rate, blastulation rate, or the probabilities of embryo transfer, implantation, or clinical pregnancy. The incidence of OHSS (all types) and OHSS requiring transvaginal paracentesis were predicted by [hCG] (P=.02 and P=.05, respectively) and with follicle count (P<.0001 in both cases). CONCLUSION(S): These results suggest that moderated hCG dosage is useful in preventing OHSS without reducing efficacy.