Criteria of a successful coasting protocol for the prevention of severe ovarian hyperstimulation syndrome.

BACKGROUND

The aim of this study is to report a large series of patients (n = 1223) at risk of developing ovarian hyperstimulation syndrome (OHSS) who underwent coasting.

METHODS

Coasting started when the leading follicle reached 16 mm and continued until the estradiol (E2) level fell to 3000 pg/ml.

RESULTS

The E2 level at the start of coasting was (mean +/ SD) 6408 +/- 446 and it fell to 2755 +/- 650 on the day of HCG injection, after (mean +/- SD) 2.89 +/- 0.94 days. The results were analysed according to the duration of coasting (< or = 3 days, group I: n = 983; >3 days, group II: n = 240). The number of oocytes retrieved was (mean SD) 16.45 +/- 6.25 and 14.93 +/- 6.01 in groups I and II respectively (P < 0.05). The fertilization rates were 63 and 65% in groups I and II respectively (P > 0.05). The implantation and clinical pregnancy rates were 26 and 52% in group I compared to 18 and 36% in group II respectively (P < 0.05). Severe OHSS occurred in 16 cases, which represented 0.13% of all stimulated cycles, and 1.3% of patients who were at risk of developing OHSS.

CONCLUSIONS

Our protocol of coasting was an effective measure in the prevention of OHSS, without jeopardizing the ICSI outcome. Coasting for >3 days is associated with a moderate decrease in the pregnancy rate.