The effects of low-dose human chorionic gonadotropin combined with human menopausal gonadotropin protocol on women with hypogonadotropic hypogonadism undergoing ovarian stimulation for in vitro fertilization

Abstract

Objectives: To investigate the effects of low-dose human chorionic gonadotropin (hCG) combined with human menopausal gonadotropin (HMG) protocol on cycle characteristics and outcomes of infertile women with hypogonadotropic hypogonadism (HH) undergoing ovarian stimulation for in vitro fertilization (IVF).

Design: A retrospective cohort study.

Setting: Tertiary-care academic medical centre.

Patient(s): Forty-six infertile patients with HH and seventy-one infertile patients with tubal factor (TF) infertility undergoing IVF.

Intervention(s): In the study group, all 46 HH patients were given low-dose hCG (50-300IU/d) in combination with HMG daily from cycle day 3. Meanwhile, a control group consisting of 71 patients with tubal factor infertility was set up, where the infertile women were given triptorelin 3.75 mg on cycle day 3 for desensitization and started stimulation with HMG only 5 weeks later. Transvaginal ultrasound and serum sex steroids were used for monitoring the development of follicles. Ovulation was triggered by hCG 5000IU when dominant follicles matured. Viable embryos were transferred on the third day after ovum pickup or cryopreserved for later transfer.

Main outcome measure(s): The primary outcome measure was the clinical pregnancy rate. Secondary outcomes included hCG day P4, ratio of E2/follicle count, number of oocytes retrieved, number of viable embryos, implantation rate, ongoing pregnancy rate and cumulative pregnancy rate.

Result(s): With lower basal FSH, LH and E2, HH patients showed longer HMG stimulation duration (13 (10-22) d vs 12 (8-18) d, P < .001) and higher HMG dose (2960 ± 560 IU vs 2663 ± 538 IU, P = .005). Whilst the antral follicle count (AFC), number of follicles with diameters greater than 10mm on trigger day and oocytes retrieved were less in the HH group, the number of follicles with diameters greater than 14 mm and viable embryos were comparable. The ratio of E2/follicle count (>10 mm) and E2/follicle count (>14 mm) were distinctively higher in the HH group (1056 ± 281 vs 830 ± 245, P < .001; 1545 ± 570 vs 1312 ± 594pmol/L, P = .037; respectively). The clinical pregnancy rate, implantation rate, ongoing pregnancy rate and cumulative pregnancy rate per woman were comparable between the two groups. Comparison among the subgroups with different hCG dosage showed that HMG duration shortened with the increase of daily hCG dose (14.84 ± 2.88 vs 13.96 ± 2.63 vs 12.96 ± 1.30 days, P = .037). No significant differences were detected in outcomes between fresh embryo transfer (ET) group and frozen-thawed embryo transfer (FET) group.

Conclusion(s): Low-dose hCG combined with HMG is a feasible protocol for HH women undergoing ovarian stimulation in IVF, providing favourable cycle characteristics and pregnancy rates. Low-dose hCG reduces HMG duration, whilst the hCG dose and embryo quality are not positively correlated. The outcomes of FET are comparable to ET, which provides a greater chance of success from IVF in the low responders with HH.

Keywords: human chorionic gonadotropin; hypogonadotropic hypogonadism; in vitro fertilization; ovarian stimulation.