The time interval between hCG priming and oocyte retrieval in ART program: a meta-analysis

Abstract

To evaluate the relationship between different hCG priming-to-oocyte retrieval intervals and assisted reproductive technology (ART) outcome. We systematically searched PubMed, EMBASE, the Cochrane Library, Science Citation Index, Chinese biomedicine (CBM) literature database, and Chinese Journal Full-text Database for randomized controlled trials (RCTs) published up to November 2010. Data was extracted from the studies by two independent reviewers. Statistical analysis was performed with Cochrane Collaboration's Review Manager (RevMan) 5.0.2. From extracted data, Risk Ratio (RR) with 95% confidence interval (CI) was calculated. 5 RCTs totaling 895 participants were included. Oocyte maturation rate was higher in the long interval group compared with short interval group (RR, 0.67; 95% CI, 0.62-0.73). There were no significant difference between the two groups with regard to fertilization rate (RR, 0.99; 95% CI, 0.94-1.04), implantation rate (RR, 0.91; 95% CI, 0.40-2.04), and pregnancy rate (RR, 0.79; 95% CI, 0.58-1.08). The percentage of mature (MII) oocytes can be increased by prolonging the interval between hCG priming and oocyte retrieval. The prolonged interval could not increase the fertilization rate, implantation rate, and pregnancy rate. Although there was evidence to confirm the results, they still need to be confirmed by large-sample, multicenter, randomized controlled trials. The time interval dependent mechanisms responsible for ART performance need to be elucidated.