Abstract: OBJECTIVE to analyze the effects of omeprazole on neonatal safety during early pregnancy through systematic literature review. METHODS The scope of the literature was English literature, published from 1998 to date. The two researchers analyzed the literature and compared the results to discuss the differences. Document quality was evaluated by Downs-Black scoring method. Random effects models were used by meta-analysis. RESULTS A total of six literature met the analytical criteria. A total of 2 161 cases exposed to PPIs in treatment group and 125 723 cases in control groups were selected for meta-analysis. There was no significant difference in neonatal malignancy between treatment group and control group, OR=1.07, CI 95%:0.82-1.40, P=0.61. In addition, evaluated the safety of omeprazole, a total of 728 cases and 2 676 cases respectively were selected for meta-analysis. The results showed that there was no significant difference in neonatal malignancy between treatment group and control group, OR=0.98, CI 95%:0.61-1.59, P=0.94. CONCLUSION As the papers included, omeprazole in the treatment of severe gastrointestinal diseases during pregnancy is relatively safe for newborns.