Clinical outcomes of natural cycle IVF/M with the different sizes of dominant follicle at the time of hCG triggering.

PURPOSE: There is infertility treatment named natural cycle in vitro fertilization (IVF) combined with in vitro maturation (IVM) of immature oocytes (natural IVF/M). The objective of this study is to investigate the clinical outcomes of hCG triggering at the different sizes of dominant follicle during the treatment. METHODS: A total of 705 patients with 1,011 natural IVF/M treatment cycles were included in this study. Among these 64 patients had repeated cycles, while 641 patients had only a single cycle. The cycles were divided into 4 groups according to the size of dominant follicle on the day of hCG injection (Group1:≤11.9 mm; Group2:12.0–13.9 mm༛Group3:14.0–15.9 mm༛Group4:≥16.0 mm).Through multivariate logistic regression analysis, candidate factors of number of mature oocytes, available and good quality embryos as well as clinical pregnancy rates were explored. RESULTS: Oocytes maturation, fertilization, cleavage, available and good quality embryo rates (p > 0.05) were no difference among 4 groups. The rates for implantation, clinical pregnancy, miscarriage, premature delivery, and live birth were similar among the groups. CONCLUSION: The presence and different sizes of the dominant follicle in the ovaries during natural cycle IVF/M does not affect clinical outcomes.