Clinical pregnancy outcome according to age of patients with high proportion of failed oocyte maturation in ICSI cases

Abstract

The purpose of this study was to compare the clinical pregnancy outcomes according to age of patients with high proportion of maturation arrest oocytes in ICSI cases. Retrospective cohort study. This study was conducted on patients with ICSI cases who had transferred embryos. Clinical outcomes were analyzed by dividing the maturation arrest rate (under 40%/over 40%) and the age of 38yrs (under 38yrs/over 38yrs). From June 2011 to December 2018, a total 2495 cycles were analyzed in this study. All the patients underwent ICSI cycle followed by fresh embryo transfer. Inclusion criteria: female age between 23 and 48yrs, use of fresh or cryopreserved sperm. Exclusion criteria: surgically retrieved sperm. These patients were divided into group A (maturation arrest rate <40%, Age <38yrs), group B (maturation arrest rate ≥40%, Age <38yrs), group C (maturation arrest rate <40%, Age ≥38yrs) and group D (maturation arrest rate ≥40%, Age ≥38yrs). The pregnancy outcomes were compared among these 4 groups. A total of 2495 cycles were included (group A (n) = 1355, group B (n) = 90, group C (n) =960 and group D (n) = 54). There was no significant differences in fertilization rate between groups (group A vs. B: 80.7% ± 20.0 vs 81.0% ± 24.1, P=0.958 and group C vs. D: 83.2% ± 20.1 vs. 88.5% ± 19.6, P=0.073). But there was a significant difference in embryo quality, pregnancy rate, and miscarriage rate. More than 40% of oocyte maturation failure group had lower levels of embryo quality. There was significant difference in at least one good quality embryo transfer cycle rate (group A vs. B: 69.4% vs. 46.7%, P<0.001 and group C vs. D: 63.1% vs. 55.6%, P<0.001). And more than 40% of oocyte maturation failure group had lower clinical pregnancy rate (group A vs. B: 41.6% vs. 20.0%, P<0.001 and group C vs. D: 25.7% vs. 7.4%, P<0.001) and ongoing pregnancy rate (group A vs. B: 35.9% vs. 14.4%, P<0.001 and group C vs. D: 17.0% vs. 1.9%, P<0.001). According to our study, high rate of oocyte maturation failure group had lower embryo quality, pregnancy rate and higher miscarriage rate. However, there was no effect on in fertilization rate. There was a similar tendency in analysis according to age. High clinical results can be maintained only by lowering the proportion of mature failed oocyte as much as possible.