Correlation of follicular fluid volume with oocyte morphology from follicles stimulated by human menopausal gonadotropin.

The maturity of human oocytes was correlated with corresponding follicular fluid volumes in 547 cycles stimulated with human menopausal gonadotropin, with or without the supplementation of follicle-stimulating hormone. Mature oocytes were found to be associated with larger follicles (average volume, 2.7 ml). Immature or degenerating oocytes were found to be associated with smaller follicles (average volume, 1.0 and 0.8 ml, respectively). Follicles without oocytes were generally quite small (average volume, 1.0 ml). We studied follicular fluid volumes associated with mature oocytes that were responsible for the establishment of pregnancy after single conceptus transfer. Analysis of these data demonstrated that the rate of spontaneous abortion was very high with conceptuses derived from smaller follicles, suggesting that oocytes from larger follicles may be of better quality.