Perivitelline space granularity: a sign of human menopausal gonadotrophin overdose in intracytoplasmic sperm injection.

The significance of the presence of coarse dark granules in the perivitelline space of oocytes has not been studied before. The study included 2288 intact oocytes [2063 in metaphase II (MII), 136 in metaphase I (MI), and 89 in germinal vesicle (GV)] retrieved in 206 intracytoplasmic sperm injection cycles stimulated by a long agonist protocol. The incidence of granules varied with oocyte maturity. It was detected in 34.3% and 4% of the MII and MI oocytes respectively, while none of the GV oocytes contained granules. The woman's age, hormonal values (oestradiol and progesterone), human chorionic gonadotrophin/oocyte retrieval interval, number of oocytes retrieved, and oocyte retrieval/injection interval were not related to the percentage of granular oocytes. Moreover, there was no correlation between the percentage of granular oocytes and the fertilization and cleavage rates, pregnancy outcome, as well as the implantation rate. Patients were divided into three groups according to the total human menopausal gonadotrophin (HMG) dose they received. There was a statistically significant difference between the three groups in the percentage of granular oocytes [17.4 +/- 5.2% versus 26.7 +/- 3.2% versus 45.4 +/- 4.2% in the low-dose (< 30 ampoules), intermediate dose (31-45 ampoules), and high-dose (> 45 ampoules) groups respectively]. We conclude that granularity in the perivitelline space is probably a physiological phenomenon related to the maturational events in oocytes and enhanced by exposure to high dosages of HMG.