#56 : Pregnancy and Live Birth Rates in Minimal Stimulation IVF Cycles from Rescue In-Vitro Maturation of Oocytes

Abstract

Background and Aims: Rescue in-vitro maturation (IVM) of immature oocytes retrieved during oocyte pick up has been shown to be a promising treatment method for infertility. The objectives of this retrospective study were 1) to determine the rescue IVM rate of immature oocytes and 2) to determine pregnancy and live birth rates. Method: Immature oocytes were classified as germinal vesicle (GV) or meiosis I (MI) oocytes. They were matured to metaphase II (MII) in-vitro and were fertilized through intracytoplasmic sperm injection. Embryos were cultured to cleavage embryos or blastocyst. Results: A total of 6,060 immature oocytes in 3,030 cycles of patients undergoing minimal stimulation IVF treatment at a private fertility clinic in the Philippines were included. Average age of the women was 36.78 ± 4.383 S.D. (min. 21, max. 50). The maturation rates to MII were 39.08% from GV and 68.05% from MI. Cleavage formation rates were 15.03% from GV and 40.35% from MI. Blastocyst utilization rates were 3.79% from GV and 16.70% from MI. Pregnancy rates (PR) were as follows: Overall - 11.3%; GV - 5.6%, and MI - 15.5%. Live birth rates (LBR) were as follows: Overall - 9.3%, GV - 4.3%, and MI - 13.3%. Age was significantly negatively correlated with PR and LBR (P<0.001). Using logistic binary regression, the predicted numbers of GV needed to achieve pregnancy and live birth were 16 and 18 oocytes, respectively; for MI these were 8.8 and 10 oocytes, respectively. These numbers are comparable to those reported in literature regarding the number of mature oocytes needed for IVF success. Conclusion: We conclude that immature oocytes that undergo rescue IVM can be as effective as mature oocytes in producing desired results in minimal stimulation IVF.