Reducing the dose of human chorionic gonadotropin in high responders does not affect the outcomes of in vitro fertilization

Abstract

Objective: The lowest effective hCG dose in high responders during IVF-embryo transfer (ET) has not been established. This study was performed to confirm that a dose of 3,300 IU is sufficient to provide adequate oocyte maturation and fertilization.

Design: Retrospective review of IVF clinical data.

Setting: Infertility center at a tertiary care university.

Patient(s): Ninety-four IVF cycles were analyzed from high responders based on peak E(2) levels. Demographics were compared including age, diagnosis, and stimulation protocol.

Intervention(s): On the day of hCG administration, if E(2) levels were >/=2,500 but <4,000 pg/mL, patients received 5,000 IU (group A). For levels between 4,000 pg/mL and 5,500 IU pg/mL, they received 3,300 IU (group B).

Main outcome measure(s): Number of oocytes retrieved, proportion of mature oocytes, fertilization rates, chemical and clinical pregnancy rates (PR). The incidence and severity of ovarian hyperstimulation syndrome (OHSS) was also analyzed.

Result(s): Mean ages were 35.4 +/- 0.7 and 33.2 +/- 0.7 for groups A and B, respectively. Peak E(2) levels differed significantly (2,907 +/- 76 vs. 4,260 +/- 129 pg/mL), as well as the mean number of eggs retrieved (15.9 +/- 0.9 vs. 20.3 +/- 1.2). Proportion of mature eggs (81.6% vs. 81.9%), fertilization rate (70.5% vs. 68.7%), chemical PR (58.7% vs. 58.7%), and clinical PR (50.0% vs. 43.5%) were similar. There was no difference in the incidence of mild, moderate, or severe OHSS.

Conclusion(s): A reduced hCG dose of 3,300 IU results in a similar proportion of mature eggs, similar fertilization rates, and similar PRs compared to 5,000 IU. Reducing the dose of hCG does not eliminate the risk of OHSS in a high-risk group.