Serum oestradiol and progesterone concentrations during prolonged coastingin 15 women at risk of ovarian hyperstimulation syndrome following ovarianstimulation for assisted reproduction treatment

Serum oestradiol and progesterone concentrations were examined for up to 7 days after withholding gonadotrophins whilst continuing pituitary down-regu lation in 15 women at serious risk of severe ovarian hyperstimulation syndr ome (OHSS) (serum oestradiol >6000 pg/ml and >15 follicles per ovary). Seru m oestradiol concentrations rose on day 1 of coasting in all but two of the 15 women before falling, the decrement being in the order of 40% on each d ay. This observation permits a rational basis for the estimation of frequen cy of serum oestradiol measurements and duration of coasting. The trends an d rates of fall of serum oestradiol do not seem to predict the occurrence o f moderate and severe OHSS, being similar in the six women who developed OH SS compared with nine women without OHSS, The trends in progesterone concen trations were unrelated to any aspects of the clinical outcome.