Miura T, Shimura M
Arch Gynecol. 1980;229(2):115-22. doi: 10.1007/BF02109950.
Seasonal birth variation was investigated in relation to the season of the mother's birth by examining: (1) 21,517 case records of a maternity hospital in Tokyo, Japan, for the period between 1925 and 1960 and (2) 2,348 questionnaires on mothers and their offsprings. In general, the birth rate was the lowest in the May--July season but mothers born in May--July of 1896 through 1915 and February--April of 1916 through 1935 had their births more evenly distributed throughout the year. The less season-sensitive mothers were more fertile than the others. The existence of some epidemic and immunogenic "seasonal infertile factors" is put forward as an explanation for these phenomena.
（1）查阅了日本东京一家妇产医院1925年至1960年期间的21517份病例记录，以及（2）2348份关于母亲及其后代的调查问卷。总体而言，出生率在5月至7月期间最低，但1896年至1915年5月至7月出生以及1916年至1935年2月至4月出生的母亲，其生育在全年分布更为均匀。对季节不太敏感的母亲比其他母亲生育能力更强。文中提出存在一些流行和免疫源性的“季节性不孕因素”来解释这些现象。
