Data from: Month of birth and risk of autism spectrum disorder, a retrospective cohort of male children born in Israel

Background: Increased incidence and prevalence of autism spectrum disorder (ASD) over the last two decades have prompted considerable efforts to investigate its etiological factors. We examined an association between month of birth and ASD incidence.
Methods: In a retrospective cohort of male children born from January 1999 to December 2008 in a large health organization in Israel (Maccabi Healthcare Services), ASD was followed from birth through December 2015.
Results: Of 108,548 boys, 975 cases of ASD were identified. The highest rates (10.3 and 10.2 per 1000 male live births) were recorded for children born in May and August, and the lowest rates for February (7.6 per 1000 male live births). Among lower socioeconomic status households, boys born in August were more likely (OR=1.71; 95% confidence interval: 1.06 – 2.74) of being diagnosed with ASD than children born in January. Significantly higher rates were not observed for other months.
Conclusions: In line with several previous studies, we found modestly higher likelihood of autism occurrence among male children of lower socioeconomic levels born in August.

背景：近二十年来，自闭症谱系障碍（Autism Spectrum Disorder, ASD）的发病率与患病率持续增长，推动学界开展了大量针对其病因学影响因素的研究。本研究旨在探讨出生月份与自闭症谱系障碍发病风险之间的关联。
方法：本研究针对以色列大型医疗保健服务机构——麦卡比医疗服务（Maccabi Healthcare Services）1999年1月至2008年12月出生的男性儿童开展回顾性队列研究，对受试者从出生至2015年12月期间的自闭症谱系障碍发病情况进行随访。
结果：在108548名男童中，共确诊975例自闭症谱系障碍病例。5月与8月出生的儿童发病率最高，分别为每1000名活产男婴10.3例和10.2例；2月出生的儿童发病率最低，为每1000名活产男婴7.6例。在社会经济地位较低的家庭中，8月出生的男童被诊断为自闭症谱系障碍的风险显著高于1月出生的男童（优势比OR=1.71；95%置信区间：1.06–2.74），其余月份未观察到显著的发病差异。
结论：与既往多项研究结果一致，本研究发现社会经济地位较低家庭中，8月出生的男童罹患自闭症谱系障碍的风险存在小幅升高。