Maternal severe stressful life events and risk of neural tube defects among rural Chinese.

BACKGROUND

Several human studies suggested an association between maternal stressful life events and increased risk of neural tube defects (NTDs). All of these studies, however, are from the United States; little was known among populations in developing countries that have different social and economic status.

METHODS

We examined the association between occurrence of maternal severe stressful life events during the periconceptional period and risk of NTDs in a population-based case-control study in Shanxi Province, China. Participants included 631 NTD cases (285 with anencephaly, 297 with spina bifida, and 49 with encephalocele) and 862 normal controls born between 2002 and 2007. Exposure information was collected within 1 week after delivery. The multivariable logistic regression model was used to estimate the adjusted odds ratio (OR) and its 95% confidence interval (95% CI) controlling for potential confounding variables.

RESULTS

Occurrence of maternal severe stressful life events was associated with a crude OR of 6.3 (95% CI, 2.8-14.4) for NTDs. After adjustment for all potential variables, the adjusted OR for NTDs remain significant (adjusted OR, 4.2; 95% CI, 1.4-12.6), and stronger for anencephaly (adjusted OR, 4.4; 95% CI, 1.2-15.9) than for spina bifida (adjusted OR, 3.4; 95% CI, 0.9-12.7). Adjustment for lifestyle variables greatly reduced the risk by 32%. A significant difference was found for some lifestyle characteristics between women with and without severe life events.

CONCLUSIONS

This study confirmed the association between maternal stress and risk of NTDs that has been consistently reported in the United States. The effect may be the combined results of maternal physiologic changes and lifestyle changes.