The value of the cervical score in monitoring ovulation induction for in vitro fertilization: a prospective double-blind study.

The present study was designed to determine the accuracy of the cervical score for the timing of human chorionic gonadotropin (hCG) administration in in vitro fertilization patients compared to the timing of hCG administration based upon estradiol and ultrasound measurements. Forty-two patients undergoing ovulation induction with human menopausal gonadotropin (hMG)/hCG for in vitro fertilization were studied. A total of 192 cervical scores was obtained together with plasma estradiol levels and pelvic sonography. hCG was given based on estradiol and ultrasound results without knowing the cervical score. An independent decision to give hCG was made based on the cervical score only following a mean of 2.5 days of a cervical score of 9-12 without the examiner's knowledge of estradiol and ultrasound results. This decision was theoretic and was not considered for the actual timing of hCG. In 16 (38%) of the cases this decision coincided with that based on estradiol and ultrasound. In 24 (57%) of the cases there was a 1-day gap. A direct correlation was found among the cervical score, the plasma estradiol concentration, and the mean diameter of the two leading follicles (P less than 0.001). The overall distribution of the cervical score grouped according to estradiol levels (less than 200, 201-400, and greater than 401 pg/ml) was significantly different (P less than 0.001). The proportion of "mature" cervical scores (score of 11-12) in the three different estradiol groups was 15.6, 34.5, and 68.0%, respectively. In conclusion, independent decisions to give hCG based on cervical score or estradiol and ultrasound were coincident +/- 1 day in 95% of the cases.(ABSTRACT TRUNCATED AT 250 WORDS)