Plasminogen Activator Inhibitor-1 Polymorphism Confers a Genetic Contribution to the Risk of Recurrent Spontaneous Abortion: An Updated Meta-Analysis.

Various studies have investigated the risk of recurrent spontaneous abortion (RSA) with plasminogen activator inhibitor-1 ( PAI-1) 4G/5G polymorphism. However, the results have been somewhat contradictory. Therefore, an updated meta-analysis based on 31 studies (5617 cases and 3952 controls) was undertaken to clarify this relationship. The degree of RSA risk was estimated using the odds ratio (OR) and the 95% confidence interval (CI). Overall, the random effects OR was 1.464 (95% CI: 1.269-1.690) for 4G versus 5G, 2.075 (95% CI: 1.563-2.754) for 4G/4G versus 5G/5G, 1.457 (95% CI: 1.211-1.753) for 4G/5G versus 5G/5G, 1.743 (95% CI: 1.358-2.236) for 4G/4G versus 4G/5G + 5G/5G, and 1.600 (95% CI: 1.327-1.930) for 4G/4G + 4G/5G versus 5G/5G, indicating that PAI-1 4G/5G polymorphism could confer an increased risk of RSA. Furthermore, a subgroup analysis showed a significantly elevated susceptibility to RSA in Asians, Caucasians, and Africans. Thus, this study demonstrated that PAI-1 4G/5G polymorphism likely confers a genetic contribution to the development of RSA. The results may aid in developing a theoretical basis for effective strategies to prevent and treat RSA.