Pregnancy outcomes after oral and injectable ovulation induction in women with infertility with a low antimüllerian hormone level compared with those with a normal antimüllerian hormone level

Objective: To determine the ongoing pregnancy rate among patients with infertility with a low antimüllerian (AMH) level compared with those with a normal AMH level after oral and injectable ovulation induction (OI)/intrauterine insemination (IUI).

Design: Retrospective cohort.

Setting: Academic center.

Patient(s): Patients completing ≥1 medicated OI/IUI cycle at our center between 2015 and 2019 were included. The AMH levels were measured within 12 months of treatment initiation. The cohort was stratified into low AMH (AMH level, <1.0 ng/mL) and normal AMH (AMH level, ≥1.0 ng/mL) groups. All subsequent medicated OI/IUI cycles occurring within 1 year of initial cycle start date were included up to the third completed cycle or until an ongoing pregnancy was recorded. Patients were stratified by age (<35, 35-40, and >40 years), and the relationship between the low and normal AMH groups and each binary endpoint were quantified as risk ratios using the age-adjusted Poisson models.

Intervention(s): None.

Main outcome measure(s): Ongoing pregnancy.

Result(s): A total of 3,122 patients completed 5,539 oral antiestrogen cycles, and 1,060 completed 1,630 injectable gonadotropin cycles. For oral antiestrogen treatment, pregnancy outcomes, including ongoing pregnancy rate per cycle, for patients with a low AMH level were comparable with those for patients with a normal AMH level (<35 years, 15.4% vs. 14.9%; 35-40 years, 10.0% vs. 11.0%; and >40 years, 2.8% vs. 3.3%). For injectable gonadotropin treatment, the ongoing pregnancy rate was lower in the low AMH group than in the normal AMH group for the ages of <35 (12.1% vs. 23.5%; relative risk [RR], 0.52 [95% confidence interval {CI}, 0.28-0.97]) and 35-40 (12.5% vs. 18.5%; RR, 0.70 [95% CI, 0.49-0.99]) years but comparable with that for patients aged >40 years (3.0% vs. 4.0%; RR, 0.86 [95% CI, 0.31-2.35]). The proportion of multifetal gestations was similar between the low and normal AMH groups treated with oral antiestrogens (13.1% vs. 10.8%); however, for injectable gonadotropin treatment, patients with a normal AMH level had a higher proportion of multifetal gestations (18.6% vs. 31.1%).

Conclusion(s): Compared with normal ovarian reserve, treatment with oral antiestrogens for OI/IUI for patients with low ovarian reserve results in comparable follicular development and ongoing pregnancy rates for all age groups. When patients with low ovarian reserve are treated with gonadotropins for OI/IUI, multifollicular recruitment is less likely resulting in a significantly decreased ongoing pregnancy rate for patients aged <35 and 35-40 years but also a decrease in multifetal gestations. Overall, the ongoing pregnancy rates of 8.7% per oral antiestrogen cycle and 8.1% per injectable gonadotropin cycle in patients with low ovarian reserve are comparable with the expected rates in the general infertility population.