Incidence and Severity of Ovarian Hyperstimulation Syndrome (OHSS) in High Responders after Gonadotropin-Releasing Hormone (gnrh) Agonist Trigger in "Freeze-All" Approach.

Objective To determine the incidence and severity of ovarian hyperstimulation syndrome (OHSS) in high responders (25-35 follicles with a diameter of >= 12 mm on day of triggering) who received a gonadotropin-releasing hormone (GnRH) agonist to trigger final follicular maturation. Methods We used individual data from women who participated in four different clinical trials and were high responders to ovarian stimulation in a GnRH antagonist protocol in this retrospective combined analysis. All women were evaluated for signs and symptoms of OHSS using identical criteria based on Golan's system (1989). Results High responders (n = 77) were of different ethnicities. There were no differences in baseline characteristics between women with or without signs and symptoms of OHSS. Mean +/- standard deviation baseline data were: age, 32.3 +/- 3.5 years; anti-Mullerian hormone, 42.4 +/- 20.7 pmol/L; antral follicle count, 21.5 +/- 9.2. Before triggering, duration of stimulation was 9.5 +/- 1.6 days and the mean number of follicles with a diameter of >= 12 mm and >= 17 mm was 26.5 +/- 4.4 and 8.8 +/- 4.7, respectively. Mean serum estradiol (17,159 pmol/l) and progesterone (5.1 nmol/l) levels were high at 36 h after triggering. Overall, 17/77 high responders (22%) developed signs and symptoms of mild OHSS which lasted 6-21 days. The most frequently prescribed medication was cabergoline to prevent worsening of OHSS. No severe OHSS occurred and no OHSS cases were reported as serious adverse events. Conclusions High responders receiving GnRH agonist for triggering should be informed that they may experience signs and symptoms of mild OHSS.