The Feasibility of Switching IVF to IVM in PCOS Patients with Unexpected Poor Ovarian Response Who Underwent Prolonged Protocol

Abstract Background With the expanding utilization of prolonged protocol, switching from in vitro fertilization to in vitro maturation (IVF/M) was a choice to prevent ovarian hyperstimulation syndrome and to avoid cycle cancellation. Our aim was to explore the feasibility of IVF/M in polycystic ovarian syndrome (PCOS) patients with unexpected poor ovarian response (UPOR) underwent prolonged protocol by comparing with IVF. Methods A retrospective analysis was performed on PCOS patients who were treated with prolonged protocol from June 2016 to December 2022. A total of 444 patients were diagnosed with unexpected poor ovarian response during ovarian stimulation. 156 patients performed IVF/M and 288 patients were treated with IVF. Laboratorial and clinical outcomes were analyzed and compared in two Groups. Results The Positive β-hCG rate (57.9%), clinical pregnancy rate (52.6%), live birth rate (38.9%) in fresh embryo transfer and cumulative live birth rate (35.3%) in IVF/M Group were lower than those in IVF Group (76.1%,66.8%,53.3%, 67.7%, respectively;all P < 0.05). The number of oocytes retrieved, mature oocytes, 2 pronuclear zygotes, embryos on day3, available blastocysts and high-quality blastocysts in IVF/M Group were less than those in IVF Group (P < 0.001). IVF/M Group gained no case of ovarian hyperstimulation syndrome (OHSS) while 59 (20.5%) patients cancelled fresh embryo transfer for OHSS and 23 (8.0%) of them were moderate to severe OHSS in IVF Group (P < 0.05). The pregnancy and neonatal complications were comparable between two groups. No dominant risk factor was found for non-live birth in fresh embryo transfer cycle. The only independent risk factor for non-live birth in cumulative cycles was IVF/M protocol. (4.58, 95%CI:2.94–7.13, P < 0.001). Conclusion IVF/M was a complement feasible choice for PCOS with UPOR who underwent prolonged protocol. Though with a lower live birth rate compared with IVF, almost one third couples still could achieve live birth and avoid neither cycle cancellation nor OHSS.