Comparison of fresh and frozen-thawed embryo transfer cycles in patients with low oocyte retrieval

To explore the choice of embryo transfer schemes for patients with low oocyte retrieval (≤ 3 oocytes).

A retrospective analysis was conducted on patients with oocyte yields ≤ 3 undergoing in vitro fertilization and embryo transfer (IVF-ET) and frozen embryo transfer (FET) at the Maternity & Child Care Center of Qinhuangdao Reproductive Medicine Department from January 2018 to December 2022. The data included 202 fresh cycles, with 104 cycles in Group-A and 98 cycles in Group-B. Additionally, 87 cycles involved the transfer of frozen embryos from fresh cycles that could not be transplanted for various reasons, with 31 cycles in Group-C and 56 cycles in Group-D. General patient information, embryo transfer details, and clinical pregnancy outcomes in both fresh and frozen cycles were statistically analyzed.

No significant differences were observed between Groups A and C in age, anti-Müllerian hormone (AMH), basal follicle-stimulating hormone (bFSH), body mass index (BMI), duration of infertility, the proportion of patients with diminished ovarian reserve (DOR), oocyte retrieval count, usable embryo count, or the number of transplanted embryos (all p> 0.05). Advanced age was a risk factor for a decreased pregnancy rate, and FET significantly increased the pregnancy rate (p< 0.05, respectively).

For patients under 35 years old with low oocyte retrieval, it is recommended to freeze all embryos when available and then proceed with FET. For patients aged 35 and above, without reducing the pregnancy rate, fresh embryo transfer is recommended to minimize treatment cycle frequency and economic expenses.