Assessing the developmental competence of oocytes matured following rescue in vitro maturation: a systematic review and meta-analysis

To assess the developmental competence of oocytes matured following rescue in vitro maturation (IVM).

PubMed, EmBASE, and SCOPUS were systematically searched for peer-reviewed original papers using relevant keywords and Medical Subject Heading terms. Study quality was assessed using the Newcastle–Ottawa Scale. Odds ratios with a 95% confidence interval were calculated by applying a random effects model. The primary outcomes were fertilization and blastulation rates. Secondary outcomes included abnormal fertilization, cleavage, euploidy, clinical pregnancy, and live-birth rates.

Twenty-four studies were included in the meta-analysis. The oocytes matured following rescue IVM showed significantly reduced fertilization, cleavage, blastulation, and clinical pregnancy rates compared to sibling in vivo–matured oocytes. No significant differences were found for the euploidy and live-birth rates in euploid blastocyst transfer. In poor responders, a reduced fertilization rate was observed using in vitro–matured GV but not with in vitro–matured MI. A reduced cleavage rate in MI matured overnight compared to < 6 incubation hours was found.

Our results showed compromised developmental competence in oocytes matured following rescue IVM. However, in poor responders, rescue IVM could maximize the efficiency of the treatment. Notably, our data suggests using in vitro MI matured within 6 incubation hours.

Clinical trial registration number: CRD42023467232.