Use of micro-dose human chorionic gonadotropin (hCG) after clomiphene citrate (CC) to complete folliculogenesis in previous CC-resistant anovulation

Abstract

The purpose of this study was to compare the effectiveness of low-dose human chorionic gonadotropin (hCG) in the late follicular phase to induce ovulation and its endocrine response in patients who had previously failed to ovulate on clomiphene citrate (CC) alone. A total of 67 patients from a private tertiary infertility clinic, who had produced a dominant follicle 12 mm or larger but 20 mm or smaller on a prior CC cycle at 100 mg but had failed to ovulate, were prospectively randomly assigned to groups. Group 1 repeated the 100 mg dose of CC but started a 200 IU hCG intramuscular injection daily when the largest follicle was 12 mm or larger mean diameter. Group 2 received a 150 mg dose of CC and both groups were monitored with transvaginal ultrasound and serum levels of E 2 , P 4 , and testosterone. Ultrasound measurements of follicle number and growth, ovulation, pregnancy rates, and serum hormonal levels were recorded and compared between the 2 groups. Analysis of variance and Student t test were used for statistical significance. The low-dose hCG group had significantly higher percentage of ovulatory cycles (57% vs 7% P < .001), peak E 2 levels (378 pg/mL vs 125 pg/mL P < .01), and pregnancy rates (18% vs 0% P < .001). This group showed no evidence of premature leutinization from the hCG with preovulatory P 4 levels less than 1.0 ng/mL and a slight increase in androgen levels. The use of micro-dose hCG after CC in the late follicular phase results in continued follicle growth, increased E 2 levels, ovulation, and pregnancies. This treatment offers an efficient and cost-effective alternative before gonadotropin therapy for this type of patient.