The value of ultrasound, gonadotropin, and estradiol measurements for precise ovulation prediction.

The exact prediction of ovulation is becoming more important in the management of infertile women. Graafian follicle diameter, measured by ultrasound and plasma follicle-stimulating hormone, luteinizing hormone, and estradiol levels were compared retrospectively as predictors of ovulation in 14 normal women in whom ovulation was dated by conventional ultrasound techniques. Follicle diameter was found to be a better predictor of the anticipated time of ovulation than endocrine estimations for short-term as well as long-term predictions in normal women. The relationship between follicle diameter and plasma estradiol for each day before ovulation was linear but contained a great amount of scatter, suggesting that the assessment of normality of follicular development in infertile women may not be possible with the use of these parameters.