Matsuda S, Hiroshige Y, Furuta M, Sone T, Doi T, Kahyo H
Department of Preventive Medicine and Community Health, School of Medicine, University of Occupational and Environmental Health, Fukuoka, Japan.
Nihon Eiseigaku Zasshi. 1994 Jun;49(2):588-97. doi: 10.1265/jjh.49.588.
Seasonal variations of the mean gestational period (MGP) and mean birth weight (MBW) are examined by the traditional method of time-series analysis during the period from 1979 to 1983 in Japan. The results of the present study support the existence of a seasonal rhythm of MGP. Generally MGP showed a deep trough in winter and a shallow one in summer to early autumn. This pattern was similar to that of MBW. The two time series showed a statistically significant coincidence in their monthly fluctuations, and a statistically significant correlation was also observed for their amplitude. According to these results, we concluded that the seasonality in MGP plays an important role in creating the seasonality in MBW. However, the seasonality in MGP can not be the only definitive factor that totally regulates the seasonal variations in MBW. The relationship between the two time series is considered to be different among different seasons as well as regions. For example, we observed a decrease of the seasonal index in winter in the same month for both MBW and MGP, but not necessarily in summer. This suggests that the etiology of the decrease in seasonal variations is different between summer and winter.
在1979年至1983年期间，采用传统的时间序列分析方法，对日本平均妊娠期（MGP）和平均出生体重（MBW）的季节性变化进行了研究。本研究结果支持MGP存在季节性节律。一般来说，MGP在冬季呈现深谷，在夏季至初秋呈现浅谷。这种模式与MBW的模式相似。这两个时间序列在月度波动上呈现出统计学上的显著一致性，并且在振幅方面也观察到了统计学上的显著相关性。根据这些结果，我们得出结论，MGP的季节性在MBW的季节性形成中起着重要作用。然而，MGP的季节性不可能是完全调节MBW季节性变化的唯一决定性因素。这两个时间序列之间的关系在不同季节和地区被认为是不同的。例如，我们观察到MBW和MGP在冬季同月的季节性指数下降，但在夏季不一定如此。这表明夏季和冬季季节性变化减少的病因是不同的。
