Accumulated Vitrified Embryos Could Be a Method for Increasing Pregnancy Rates in Patients with Poor Ovarian Response

We aimed to assess the efficacy of accumulated embryo transfer (ACC-ET) through several controlled ovarian hyperstimulation (COS) cycles to increase the rates of pregnancy in patients with poor ovarian response (POR). We retrospectively reviewed the medical records of 588 patients with POR under 43-years old who underwent embryo transfer from January 2010 to December 2015. We compared the pregnancy rate (PR), clinical pregnancy rate (CPR), and live birth rate (LBR) between ACC-ET (frozen-thawed: 47; fresh + frozen-thawed: 24) group (n = 71) and fresh ET groups (n = 517). Characteristics of ACC-ET patients were similar to those of fresh ET groups (Age: 38.1 +/- 3.5 vs. 38.2 +/- 3.7, p = 0.88; Anti Mullerian Hormone (AMH; ng/mL): 0.5 +/- 0.4 vs. 0.6 +/- 0.6, p = 0.38; follicle stimulating hormone (FSH: mIU/mL): 11.9 +/- 8.0 vs. 10.8 +/- 9.0, p = 0.35). The total number of transferred embryos (3.1 +/- 0.9 vs. 1.5 +/- 0.7, p = 0.00), PR (29.6% (21/71) vs. 18.8% (97/517), p = 0.040), and CPR (23.5% (16/68) vs. 14.0% (71/508) p = 0.047) were significantly higher in the ACC-ET group than in the fresh ET group. In addition, PR, CPR, and LBR increased with the number of ET in the fresh ET group. However, there were no significant differences observed in LBR between ACC-ET and fresh ET groups (14.9% (10/67) vs. 9.8% (50/508), p = 0.203). From our knowledge, there is no clinical evidence reported to prove that transfer of multiple embryos of adequate quality obtained through multiple cycles can compensate for the limited number of retrieved oocytes from POR patients. We concluded that ACC-ET from several COS cycles could be an alternative method to increase PR and CPR in <43-year-old patients with POR.