Department of Obstetrics and Gynecology, University of Milano Bicocca, Monza, Italy.
Prenat Diagn. 2013 Oct;33(10):1007-9. doi: 10.1002/pd.4175. Epub 2013 Jul 19.
To evaluate whether a relationship exists between season at conception and occurrence of isolated spina bifida (ISB).
All fetuses with prenatal diagnosis of ISB were analyzed according to date of conception. We compared the seasonal rates of conception between ISB fetuses and a control group consisting of a cohort of fetuses delivered during the same period from 1992 to 2009.
In the control group, conceptions were equally distributed among the four seasons. Chi-square analysis showed a significantly higher rate of ISB conceptions in the fall compared with the control group (16/36, 44% vs. 12467/50533, 25%, Odds Ratio (OR) 2.44, 95% confidence interval 1.21-4.92). Not a single woman with a fetus affected by ISB took preconceptional supplement of folic acid.
Seasonality affects the frequency of ISB. We hypothesize that the seasonal differences may reflect dietary and climate changes with reduced intake of folic acid in the fall.
评估受孕季节与单纯性脊柱裂（ISB）发生之间是否存在关系。
根据受孕日期分析所有产前诊断为 ISB 的胎儿。我们比较了 ISB 胎儿与同期（1992 年至 2009 年）分娩的胎儿队列组成的对照组之间的受孕季节率。
在对照组中，四个季节的受孕率相等。卡方分析显示，秋季 ISB 受孕率明显高于对照组（16/36，44% vs. 12467/50533，25%，优势比（OR）2.44，95%置信区间 1.21-4.92）。没有一位孕妇在受孕前补充过叶酸。
季节会影响 ISB 的发生频率。我们假设季节性差异可能反映了秋季叶酸摄入减少的饮食和气候变化。
