RESUMO
BACKGROUND: Neural tube defects (NTDs) are common and serious birth defects all over the world. Prenatal screening for NTDs using maternal serum alpha-fetoprotein (MSAFP) during the second trimester of pregnancy has been widely used, but its effectiveness remains unclear. METHODS: We evaluated the studies published in the English and Chinese on MSAFP screening for NTDs. The homogeneity of the studies was evaluated by the forest graph. Meta-analysis was applied to calculate the combined effect values and their 95% confidence intervals. RESULTS: As many as 22 articles were selected according to the criteria and were included in the meta-analysis, for a total of 684,140 pregnant women screened during the second trimester. All the studies selected were homogenous according to the forest graph (chi(2) = 25.17, P > 0.10). The combined relative risk estimate was 0.25 and its 95% confidence interval was 0.21 to 0.29. The combined protective rate was 75%. The sensitivity and specificity of MSAFP screening were 75.1 and 97.7%, respectively. CONCLUSION: Use of MSAFP during the second trimester in pregnant women is an effective measure for the screening of NTDs.