中文摘要：

目的分析出生季节与初潮年龄、绝经年龄及生育年限间的关联。方法研究对象来自中国慢性病前瞻性研究的基线调查数据，剔除初潮年龄在生理范围外（〈9岁或〉18岁）的个体后，纳入285186名女性进行初潮年龄相关分析；在已绝经的女性中排除因施行子宫切除术或卵巢摘除术绝经者，纳入132373人进行绝经年龄及生育年限相关分析。统计分析采用多元线性回归模型。结果在调整了可能的混杂因素后，与春季出生的女性相比，出生于夏、秋及冬季的女性初潮年龄平均晚0．14（95％CI：0．13～0．16）、0．26（95％CI：0．24～0．27）及0．10（95％CI：0．08—0．12）岁，绝经年龄依次晚0．14（95％C1：0.08～0．20）、0．18（95％C1：0．12～0．24）及0．09（95％CI：0．03～0．16）岁。生育年限与出生季节无关。上述关联在城市和农村地区、不同出生年代的女性中均是一致的。结论出生于春季的女性初潮年龄及绝经年龄均更早。本研究结果提示生命早期某些与季节相关的因素可能会影响女性生殖系统的发育。

英文摘要：

Objective To examine the associations between season of birth and factors as age at menarche, age at menopause and reproductive span. Methods A total of 285 186 female from the China Kadoorie Biobank, with complete data on critical variables and had menarche at 9-18 years old, were included. A total of 132 373 female with natural menopause were included for the analysis on age at menopause and reproductive span. Multiple linear regression models were used to assess the associations of birth season and the age at menarche, menopause, and reproductive span. Subgroup analyses were performed on birth cohorts and urban/rural residence. Results Compared with the Spring-born （March, April, and May）, participants who were born in Summer （June, July, and August）, Autunm （September, October, and November）, and Winter （December, January, and February） appeared late on both age at menarche and menopause. Multivariable-adjusted coefficients （95% CI） appeared as 0.14 （95%CI： 0.13-0.16）, 0.26（95%CI： 0.24-0.27）, 0.10 （95%CI： 0.08-0.12） for age at menarche respectively and 0.14 （95%CI： 0.08-0.20）, 0.18 （95%CI： 0.12-0.24）, 0.09 （95%CI： 0.03-0.16） for age at menopause respectively. No statistically significant association was found between the season of birth and reproductive span. The association was consistent between urban and rural residents and across the birth cohorts. Conclusions female born in spring showed both earlier age on both menarche and menopause, compared to the ones born in other seasons. Our findings suggested that exposures in early life with some degree of seasonal variation might influence the development of female reproductive system.