Abstract: Objective To explore the association between Mh infection and adverse pregnancy outcomes. Methods Some electronic databases including PubMed, Web of Science, EMBASE, CNKI, VIP, and Wanfang database were researched for mycoplasma and adverse pregnancy outcomes, including premature delivery, premature rupture of membranes, spontaneous abortion or low birth weight. Stata 12.0 software was used for the meta analysis.The NOS scale was used to evaluate the quality of the literature. Publication bias was evaluated by funnel figure, Begg Egger, and the fail-safe number was calculated to estimate the reliability of the meta analysis. Results 32 articles were included, the numbers of cases and controls were 3 236 and 4 310, respectively. The pooled OR value（pooled OR’s 95%CI） of Mh infection in pregnant women and adverse pregnancy outcomes was 3.13（95%CI 2.64~3.70）. And the differences among Mh infectionand different pregnancy outcomes were statistically significant, premature delivery: OR=3.43（95%CI 2.17~5.44）; premature rupture of membranes: OR=2.56（95%CI 1.33~4.90）; spontaneous abortion: OR=3.38（95%CI 2.62~4.35）; the differences between Mh infection and adverse pregnancy outcomeswere also statistically significant in different research types case control study: OR=2.98（95%CI 2.46~3.60; cohort study: RR=2.88（95%CI 2.16~3.83）. About regions, Chinese people: OR=3.32（95%CI 2.75~4.01）; non-Chinese people: OR=2.41（95%CI 1.65~3.52）. The funnel figure was fundamental symmetric. P values of Begg and Egger test were 0.05 and 0.13 respectively, the fail-safe number was 1 825. Conclusion Mh infection among pregnant women might contribute to adverse pregnancy outcomes.