Increased versus standard gonadotrophin dosing in predicted poor responders of IVF: an open-label randomized controlled trial

Abstract

Study question: Does an increased dosing of FSH improve the live birth rate as compared to standard FSH dosing in expected poor responders who undergo IVF?

Summary answer: In this trial, women with an expected poor response allocated to increased FSH dosing did not have a statistically significant increase in cumulative live births as compared to a standard FSH dose.

What is known already: Poor ovarian reserve leads to worse IVF outcomes owing to the low number and quality of oocytes. Clinicians often individualize the FSH dose using ovarian reserve tests, including antral follicle count (AFC), and basal plasma FSH or anti-Müllerian hormone level. However, the evidence that increased FSH dosing improves fertility outcomes in women with an expected poor response is lacking.

Study design, size, duration: We performed a parallel, open-label randomized controlled trial between March 2019 and October 2021 in an assisted reproduction centre.

Participants/materials, setting, methods: Women <43 years of age with AFC <10 referred for their first IVF cycle were randomized for increased or standard FSH dosing. In participants allocated to increased FSH dosing, women with AFC 1-6 started with 300 IU/day, while women with AFC 7-9 started with 225 IU/day. In participants allocated to the standard care, women started with 150 IU/day. The primary outcome was cumulative live birth attributable to the first IVF cycle including fresh and subsequent frozen-thawed cycles within 18 months of randomization. Live birth was defined as the delivery of one or more living infants ≥24 weeks' gestation. This trial was powered to detect an 11% difference in live birth attributable to the first IVF cycle. Outcomes were evaluated from an intention-to-treat perspective.

Main results and the role of chance: We randomized 661 women to start FSH at increased dosing (n = 328) or standard dosing (n = 333). The primary outcome cumulative live birth occurred in 162/328 (49.4%) women in the increased group versus 141/333 (42.3%) women in the standard group [risk ratio (RR) 1.17 (95% CI, 0.99-1.38), risk difference 0.07 (95% CI, -0.005, 0.15), P = 0.070]. The live birth rate after the first embryo transfer in the increased versus standard group was 125/328 (38.1%) versus 117/333 (35.1%), respectively [RR 1.08 (95% CI, 0.83-1.33), P = 0.428]. Cumulative clinical pregnancy rates were 59.1% versus 57.1% [RR 1.04 (95% CI, 0.91-1.18), P = 0.586] with miscarriage rates of 9.8% versus 14.4% [RR 0.68 (95% CI, 0.44-1.03), P = 0.069] in the increased versus standard group, respectively. Other secondary outcomes, including biochemical pregnancy, ongoing pregnancy, multiple pregnancy and ectopic pregnancy, were not significantly different between the two groups both from the first and cumulative embryo transfer.

Limitations, reasons for caution: As this study is open-label, potential selective cancelling and small dose adjustments could have influenced the results.

Wider implications of the findings: In women with predicted poor response, we did not find evidence that increased FSH dosing improves live birth rates. A standard dose of 150 IU/day is recommended at the start of IVF in these women to reduce potential adverse effects and costs.

Study funding/competing interest(s): This study was funded by the General Projects of Social Development in Shaanxi Province (No. 2022SF-565). B.W.M. is supported by NHMRC (GNT1176437). B.W.M. reports personal fees from ObsEva, and funding from Merck and Ferring outside the submitted work.

Trial registration number: Registered at Chinese clinical trial registry (www.chictr.org.cn). Registration number ChiCTR1900021944.

Trial registration date: 17 March 2019.

Date of first patient’s enrolment: 20 March 2019.

Keywords: FSH; IVF; increased dosing; individualized dose; live birth; poor response; standard dosing.