Caton Alissa R
University at Albany, Department of Epidemiology and Biostatistics, Rensselaer, New York 12144-3456, USA.
Birth Defects Res A Clin Mol Teratol. 2012 Jun;94(6):424-37. doi: 10.1002/bdra.23006. Epub 2012 Apr 4.
Examining seasonal patterns of birth defects may help to identify environmental risk factors. Because the teratogenic window for most birth defects is during gestational weeks 3 to 8, investigating exposures closer to the timing of conception is important. However, studies are usually based on month of birth, which is not the biologically relevant exposure period and does not account for differences in gestational length. We aimed to determine whether the occurrence of birth defects varied by month of conception using the population-based New York State Congenital Malformations Registry (CMR).
We merged live birth certificates (n = 2,044,091) with CMR records for mothers residing in New York State, excluding New York City, for the years 1992 through 2006. We categorized birth defects according to the National Birth Defects Prevention Network guidelines and performed Cochran-Armitage trend, Hewitt-Rogerson, and Walter-Elwood tests on month of conception and chi-square tests on season of conception. We graphed seasonal distributions and seasonality test results. We performed stratified analyses by maternal and infant characteristics.
Of 42 groups examined in the 15-year period, 24 (57%) had at least one statistically significant test result, suggesting a trend or seasonal variation: Cochran-Armitage (18), Hewitt-Rogerson (17), Walter-Elwood (4), and chi-square (5). Ventricular septal defect showed the most consistent results: Cochran-Armitage (p = 0.0006), Hewitt-Rogerson (December to May; p = 0.0130), Walter-Elwood (March 14; p = 0.0027), and chi-square (winter; p = 0.0046). Congenital cataract, pulmonary valve atresia/stenosis, coarctation of aorta, biliary atresia, and renal agenesis or hypoplasia had at least three significant tests.
These results may help to generate hypotheses about environmental factors that vary by season for further studies.
研究出生缺陷的季节性模式可能有助于识别环境风险因素。由于大多数出生缺陷的致畸窗口期在妊娠第3至8周，因此调查更接近受孕时间的暴露情况很重要。然而，研究通常基于出生月份，这并非生物学上相关的暴露期，且未考虑妊娠期长度的差异。我们旨在利用基于人群的纽约州先天性畸形登记处（CMR）来确定出生缺陷的发生是否因受孕月份而异。
我们将1992年至2006年居住在纽约州（不包括纽约市）的母亲的出生证明（n = 2,044,091）与CMR记录进行合并。我们根据国家出生缺陷预防网络指南对出生缺陷进行分类，并对受孕月份进行 Cochr an - Armitage趋势检验、Hewitt - Rogerson检验和Walter - Elwood检验，对受孕季节进行卡方检验。我们绘制了季节性分布和季节性检验结果。我们按母亲和婴儿特征进行了分层分析。
在15年期间检查的42组中，24组（57%）至少有一项具有统计学意义的检验结果，表明存在趋势或季节性变化： Cochr an - Armitage检验（18组）、Hewitt - Rogerson检验（17组）、Walter - Elwood检验（4组）和卡方检验（5组）。室间隔缺损显示出最一致的结果： Cochr an - Armitage检验（p = 0.0006）、Hewitt - Rogerson检验（12月至5月；p = 0.0130）、Walter - Elwood检验（3月14日；p = 0.0027）和卡方检验（冬季；p = 0.0046）。先天性白内障、肺动脉瓣闭锁/狭窄、主动脉缩窄、胆道闭锁以及肾缺如或发育不全至少有三项显著检验结果。
这些结果可能有助于生成关于随季节变化的环境因素的假设，以供进一步研究。
