'Early coasting' in patients with polycystic ovarian syndrome is consistent with good clinical outcome

Coasting can be an effective strategy for the prevention of severe ovarian hyperstimulation syndrome (OHSS) during ovarian stimulation. However, OHSS may still occur in cases of excessive follicular response (i.e. >10 follicles/ovary and serum estradiol (E(2)) concentration >3000 pg/ml). Furthermore, prolonged coasting may result in a reduction of the oocyte retrieval rate and embryo quality. This pilot study investigates the potential of withholding gonadotrophins at an earlier stage, with the intention of minimizing these risks.

Gonadotrophin injections were withheld for a fixed period of 3 days once the leading follicle was 15 mm, whilst continuing pituitary down-regulation in 102 obese patients with polycystic ovarian syndrome (PCOS) in whom there was evidence of excessive ovarian follicular response (>10 follicles per ovary and serum E(2) >1500 but <3000 pg/ml). The events of ovarian stimulation, embryological and clinical outcomes were studied prospectively.

The mean number of ampoules (75 IU per ampoule) of high purity (hp) FSH was 23.2. The mean serum E(2) level on coasting day 1 was 1943.7 and 2169.2 pg/ml on the day of HCG administration. Normal fertilization and cleavage rates were obtained despite early withdrawal of hpFSH in the obese PCOS patients, being 73.9 and 87.7% respectively. The clinical pregnancy rate was 45.1%. There were no cases of severe OHSS. Four patients suffered pregnancy-associated late-onset moderate OHSS.

This pilot study suggests that withholding gonadotrophins at an earlier stage in patients with excessive ovarian follicular response at anticipated risk of developing severe OHSS in the course of ovarian stimulation is consistent with good embryological and clinical outcome in IVF and ICSI treatment cycles.