Objective: To explore the periconceptional factors affecting the risk of neural tube defects (NTDs), we carried out a hospital-based case-control study in China.
Methods: A 1:1 matched case-control study was conducted. With self-designed questionnaires, we solicited relevant information from 459 case mothers and 459 control mothers selected in two provinces of China through face-to-face interviews. Univariate and multivariate conditional logistic regression analyses were conducted to evaluate the effect values by odds ratios (ORs) and 95% confidence intervals (95%CIs) with SAS9.1.3.software.
Results: Daily passive tobacco smoke exposure was a risk factor for total NTDs (OR = 8.688, 95%CI = 2.329-32.404). Diet adjustment in the first trimester (OR = 0.061, 95%CI = 0.014-0.274), periconceptional folic acid intake (OR = 0.059, 95%CI = 0.011-0.321) and health education (OR = 0.251, 95%CI = 0.081-0.781) were protective factors for total NTDs. Differences in factors and their effects on NTDs were found for the three subtypes of NTDs: anencephaly, spina bifida and encephalocele.
Conclusions: Daily passive tobacco smoke exposure, diet adjustment in the first trimester, periconceptional folic acid intake and health education were associated with NTDs.