Monitoring of ovulation induction with HMG-HCG therapy by plasma estrogen and progesterone.

Seventeen patients with anovulation or luteal deficiency were tested with HMG-HCG for 40 cycles. Follicular development was monitored daily by measurement of immunoreactive plasma estrogen. Ovulation was evaluated by determination of plasma progesterone. Ovulation was induced in 16 patients and 37 of 40 cycles (93%). Fourteen pregnancies occurred in 13 patients. Plasma estrogen measurements in ovulatory cycles at the time of HCG injection ranged from 315 to 1,482 pg/ml (mean 764 pg/ml). Mild hyperstimulation occurred in two cycles with preovulatory estrogen values of 720 pg/ml and 784 pg/ml. The highest preovulatory estrogen level which was followed by anovulation was 493 pg/ml. The preovulatory estrogen peak in one triplet pregnancy measured 1,356 pg/ml. Determinants of treatment failure included inadequate follicular stimulation, interruption of HMG therapy for more than 1 day, previous ovarian wedge resection, and congenital anomaly of the uterus. Increase in body weight required higher doses of drug therapy in one case. We conclude that optimal estrogen levels prior to HCG injection range from 500 to 700 pg/ml. The risks for ovarian hyperstimulation and multiple pregnancy may be reduced and ovulation accomplished by daily administration of HMG until the defined estrogen level is reached.