The Effects of Preconception Examinations on Neural Tube Defects and the Primary Preventive Measures: Case-control Study.

Background: Preventive measures for neural tube defects (NTDs) have been recommended for many years in China, but the compliance with these measures is unsatisfactory. This study aims to analyze the effects of preconception examinations on NTDs and its primary preventive measures. Methods: A 1:1 hospital-based case-control study was conducted. Four hundred and fifty-nine women who delivered or gestate infants/fetuses with NTDs from January 2006 to December 2008 were randomly selected and matched with women who delivered babies without obvious birth defects as controls in Shandong and Shanxi province. Multivariate conditional logistic regression was adopted. Results: Significant associations were shown between preconception examinations (OR = 0.461), health education (OR = 0.336), periconceptional folic acid supplement (OR = 0.295), periconceptional rational diet adjustment (OR = 0.278) and NTDs. In the case group, the rates of periconceptional folic acid supplement and health education conduction by women who had preconception examinations were significantly higher than that of those who had not, OR being 3.04 and 4.55, respectively (p<0.05). Among the preventive effects on NTDs, preconception examinations and other NTDs primary preventive measures had significant combined effects and the combined effects with periconceptional folic acid supplement were the greatest, with OR of 0.04. Conclusion: Preconception examinations have preventive effects on NTDs and can significantly improve the compliance of other NTDs primary preventive measures. In addition, preconception examinations and these measures have synergetic prevention effects, indicating the critical role played by preconception examinations on NTDs prevention.