Low oocyte maturity ratio is associated with a reduced in vitro fertilization and intracytoplasmic sperm injection live birth rate

To determine whether a low oocyte maturity ratio in a cohort of oocytes from an in vitro fertilization cycle predicts outcomes and to examine clinical factors associated with oocyte maturity.A retrospective cohort study.An academic medical center.Determination of oocyte maturity immediately after the retrieval and 6 hours later if intracytoplasmic sperm injection was performed.The primary outcome was live birth rate after the first embryo transfer. Secondary outcomes included clinical pregnancy, miscarriage, and fertilization rates.After adjusting for age, preimplantation genetic testing, and number of embryos transferred, we found that a low oocyte maturity ratio was associated with a decreased live birth rate (adjusted odds ratio [AOR], 0.41; 95% confidence interval [CI], 0.22-0.77) and clinical pregnancy rate (AOR, 0.32; 95% CI, 0.17-0.61). We did not find a relationship between oocyte maturity and miscarriage rate (AOR, 0.25; 95% CI, 0.03-1.91) or fertilization rate (Welch test). The number of 2 pronuclei embryos per retrieved oocyte was found to be associated with the maturity ratio at retrieval. Patients with anovulation had slightly reduced oocyte maturity compared with other diagnostic groups.Low oocyte maturity ratio is an important factor related to poor in vitro fertilization outcomes, including decreased pregnancy and live birth rates.