Résumé
Objective To investigate the impact of pregnancy complications and gestational exposure to toxic chemical on birth defect,to provide scientific basis for effective intervention measures.Methods 11 studies were included,the quality evaluation and information extraction were carried out on the studies according to include and exclude standard.3 248 examples in case group and 5 722 examples in control group.Fixed or random effects model was used according to heterogeneity test results,and the combined result was analyzed by Chi -square test.The publi-cation bias of the studies was also evaluated.Results The combined results of single factor analysis of pregnancy complications was 1.074(0.926 -1.222),showed that pregnancy complications were risk factors of birth defects.The combined results of single factor and multiple factors analysis of gestational exposure to toxic chemical were 1.426 (1.147 -1.704),1.421(1.174 -1.668),also showed that gestational exposure to toxic chemical was a risk factor of birth defects.Conclusion Pregnancy complications and gestational exposure to toxic chemical are risk factors of birth defects,this targeted provides reference to birth defects prevention.