Objective: The aim of this analysis was to demonstrate the association between melatonin levels and the development of preeclampsia. Methods: Standardized mean difference (SMD) with 95% confidence interval (CI) was calculated using a random effects model. Results: The pooled SMD between case and control was 1.40 (95% CI: 0.26, 2.55; P = 0.02). And the pooled SMD between mild PE and severe PE was 5.25 (95% CI: 1.5, 9.01; P = 0.006). Conclusion: The meta-analysis illustrated that melatonin concentration was significantly lower in women with preeclampsia, and correlated with the severity of the disease. |