Prevention of severe ovarian hyperstimulation by coasting.

OBJECTIVE

To evaluate the efficiency of withholding gonadotropins and deferring the administration of hCG until E2 levels start dropping (coasting) in the prevention of ovarian hyperstimulation syndrome (OHSS) in a high-risk population.

DESIGN

Retrospective case-control study.

SETTING

In vitro fertilization program at a university center.

PATIENT(S): The case group consisted of 120 women undergoing ovarian stimulation for IVF who were considered to be at risk for ovarian hyperstimulation (serum E2 levels >2,500 pg/mL or >20 follicles at the time of hCG administration).

INTERVENTION(S): Gonadotropin administration was withheld when serum E2 levels exceeded 2,500 pg/mL, and hCG administration was delayed until E2 levels dropped below 2,500 pg/mL. Outcomes were compared with those from 120 matched patients in whom serum E2 levels and the number of follicles at the time of hCG administration were comparable to those at the beginning of coasting (control group).

MAIN OUTCOME MEASURE(S): Incidence of moderate and severe OHSS. The number of oocytes retrieved and pregnancy rate (PR) were compared in both groups.

RESULT(S): Coasting decreased the incidence of moderate and severe OHSS. The odds ratio of severe OHSS in the coasting group was 0.11 (95% confidence interval 0.01-0.86). Although the number of oocytes was significantly lower in the coasting group (19.7 +/- 0.6 versus 22.1 +/- 0.6), coasting did not affect the PR (37.5% versus 36.7%).

CONCLUSION(S): Our study indicates that coasting is an efficient method for reducing the incidence and severity of OHSS without compromising the PR.