OVULATION TRIGGERING IN CLOMIPHENE CITRATE-STIMULATED CYCLES - HUMAN CHORIONIC-GONADOTROPIN VERSUS A GONADOTROPIN-RELEASING-HORMONE AGONIST

Purpose: To compare the Iue of human chorionic gonadotropin (hCG) to a gonadotropin releasing hormone (GnRH) agonist, nafarelin, in initiati ng ovulation and supporting the luteal phase after priming with clomip hene. Methods: In 26 infertile women 50 mg clomiphene citrate produced a preovulatory-size follicle. Then, 11 women were randomized to recei ve two 400-mu g doses of nafarelin intranasally 16 h apart, and 15 wom en were injected intramuscularly with 5000 IU of hCG (luteal day 0 = L D0). Starting on LD6, 7 move 400-mu g doses of nafarelin were repeated on an every 16-h schedule or a single 2500 IU dose of hCG was given, 1 espectively. Serum levels of follicle stimulating hormone (FSH), lut einizing hormone (LH), estradiol (E(2)), progesterone (P), and hCG wer e measured. On LD13, endometrium was evaluated with ultrasonography an d biopsy in 19 nonpregnant women. Results: As judged by a threefold ri se in serum LH, an LH surge was detected on LD1 in all 11 nafarelin pa tients, but in only 8 hCG patients (P = 0.01). LH and FSH levels were significantly higher on LD1, 7, and 8 and were significantly suppresse d on LD13 in the nafarelin group. All patients had mid-luteal P levels greater than 10 ng/ml and luteal phases longer than 13 days. Signific antly different luteal E(2) or P levels were noted only on LD13, with lower values in the nafarelin group. Pregnancies were achieved in 3 of 11 nafarelin cycles and 2 of 15 hCG cycles. Luteal phase defects were also similar: 4 of 8 nafarelin patients and 7 of 11 hCG patients. Con clusion: Nafarelin or hCG in conjunction with clomiphene can result in viable pregnancies, but is associated with low pregnancy rates and a high incidence of luteal phase defects.