Clinical outcomes of long follicular-phase protocol in first-cycle patients with diminished ovarian reserve and AMH<1.2 ng/mL: A single-center study

This study aims to compare the outcomes of assisted reproductive treatment in women with low ovarian reserve (LOR), defined as an anti-Müllerian hormone level of ≤1.2 ng/mL, versus normal ovarian reserve (NOR; 1.2 ng/mL < anti-Müllerian hormone ≤3.0 ng/mL) using the long follicular-phase protocol. It further evaluates the efficacy of the long follicular-phase, antagonist, and progestin-primed ovarian stimulation (PPOS) protocols specifically within the LOR population. A retrospective analysis was conducted on 2309 patients treated between October 2022 and October 2024. Participants included 973 LOR patients and 1336 NOR patients. LOR patients were divided by protocol: Group A (long follicular-phase protocol, n = 95), Group C (antagonist, n = 200), and Group D (PPOS, n = 678). All NOR patients received the long follicular protocol (Group B, n = 1336). Groups were stratified by age (<35 and ≥35 years). Regarding the long follicular protocol: In women <35, Group A had significantly fewer retrieved oocytes and high-quality embryos than Group B (P <.05), yet clinical pregnancy and live birth rates (LBRs) were similar (P >.05). In women ≥35, Group A had fewer oocytes but a higher MII rate than Group B, with no significant difference in pregnancy or live birth rates. Comparing protocols within the LOR population: Group A exhibited significantly lower baseline hormone levels but higher numbers of punctured follicles, retrieved oocytes, and 2PN fertilized oocytes compared to Groups C and D (P <.05). Notably, among patients ≥35, Group A produced significantly more high-quality embryos. Generally, age negatively impacted outcomes across all groups. For individuals with LOR, the long follicular-phase protocol yields clinical pregnancy and live birth rates comparable to those with normal reserve, despite lower oocyte yield. Our research findings, while not conclusive in the LOR population, suggest a possible trend that long follicular-phase protocol may offer certain advantages over antagonist and PPOS protocols in key experimental parameters. Nevertheless, age remains a key factor affecting stimulation response.