McGrath John J, Keeping Douglas, Saha Sukanta, Chant David C, Lieberman Daniel E, O'Callaghan Michael J
Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, QLD 4076, Australia.
Early Hum Dev. 2005 Jul;81(7):609-18. doi: 10.1016/j.earlhumdev.2005.03.013.
Birth weight is known to fluctuate with season of birth, however, there is little information about seasonal variation in neonatal anthropometric measures.
The aim of this study was to examine seasonal fluctuations in birth weight and selected anthropometric measures.
The birth weight of singletons born after at least 37 weeks gestation was extracted from a perinatal register in south-east Queensland (n=350,171). Mean monthly birth weights for this period were examined. Based on a separate birth cohort, principal component analysis was undertaken on neonatal anthropometric measures (n=1233). Seasonality was assessed by (a) spectral analysis of time series data, (b) monthly and seasonal comparison of outcomes.
Based on register data, birth weight displayed clear annual periodicity. Birth weight differed significantly when compared by month and season. Infants born in October were the heaviest (3484 g), while May-born infants were the lightest (3459 g; P=0.001). Based on the cohort anthropometric data, three components were identified related to (a) overall size, (b) limb length, and (c) head size and skin-fold thickness. Each of these components displayed significant seasonal variation. In particular, prominent seasonal fluctuations in limb length were identified, with peak limb length associated with winter/spring birth.
Environmental factors that have regular seasonal fluctuation influence both the size and shape of neonates. Animal experiments suggest that prenatal hypovitaminosis D may underlie greater limb length. Because birth weight and limb length are associated with a broad range of important health outcomes, the seasonal exposures underlying these effects warrant further scrutiny from a public health perspective.
已知出生体重会随出生季节波动，然而，关于新生儿人体测量指标的季节性变化信息较少。
本研究的目的是检查出生体重和选定人体测量指标的季节性波动。
从昆士兰东南部的围产期登记册中提取至少妊娠37周后出生的单胎婴儿的出生体重（n = 350,171）。检查了该时期的平均每月出生体重。基于一个单独的出生队列，对新生儿人体测量指标（n = 1233）进行了主成分分析。通过（a）时间序列数据的频谱分析，（b）结果的月度和季节比较来评估季节性。
根据登记数据，出生体重呈现明显的年度周期性。按月和季节比较时，出生体重有显著差异。10月出生的婴儿最重（3484克），而5月出生的婴儿最轻（3459克；P = 0.001）。基于队列人体测量数据，确定了三个与（a）总体大小、（b）肢体长度和（c）头部大小及皮褶厚度相关的成分。这些成分中的每一个都显示出显著的季节性变化。特别是，发现肢体长度有明显的季节性波动，肢体长度峰值与冬季/春季出生相关。
具有定期季节性波动的环境因素会影响新生儿的大小和形状。动物实验表明，产前维生素D缺乏可能是肢体长度增加的基础。由于出生体重和肢体长度与一系列重要的健康结果相关，从公共卫生角度来看，这些影响背后的季节性暴露值得进一步审查。
