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

Objective: 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.

Design: A retrospective cohort study.

Setting: An academic medical center.

Intervention(s): Determination of oocyte maturity immediately after the retrieval and 6 hours later if intracytoplasmic sperm injection was performed.

Main Outcome Measure(s): The primary outcome was live birth rate after the first embryo transfer. Secondary outcomes included clinical pregnancy, miscarriage, and fertilization rates.

Result(s): 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.

Conclusion(s): Low oocyte maturity ratio is an important factor related to poor in vitro fertilization outcomes, including decreased pregnancy and live birth rates.