Field Epidemiololgy
Associations between season of birth and age both at menarche and at menopause
Jiahui Si, Ruogu Meng, Jun Lyu, Yu Guo, Zheng Bian, Canqing Yu, Ling Yang, Yunlong Tan, Pei Pei, Junshi Chen, Zhengming Chen, Liming Li, for the China Kadoorie Biobank (CKB) Collaborative Group
Published 2017-07-10
Cite as Chin J Epidemiol, 2017, 38(7): 877-882. DOI: 10.3760/cma.j.issn.0254-6450.2017.07.006
Abstract
ObjectiveTo examine the associations between season of birth and factors as age at menarche, age at menopause and reproductive span.
MethodsA 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.
ResultsCompared with the Spring-born (March, April, and May), participants who were born in Summer (June, July, and August), Autumn (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.
Conclusionsfemale 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.
Key words:
Birth season; Early life; Age at menarche; Age at menopause; Reproductive span
Contributor Information
Jiahui Si
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China
Ruogu Meng
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China
Jun Lyu
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China
Yu Guo
Chinese Academy of Medical Sciences, Beijing 100010, China
Zheng Bian
Chinese Academy of Medical Sciences, Beijing 100010, China
Canqing Yu
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China
Ling Yang
Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford OX1 3QR, UK
Yunlong Tan
Chinese Academy of Medical Sciences, Beijing 100010, China
Pei Pei
Chinese Academy of Medical Sciences, Beijing 100010, China
Junshi Chen
China National Center for Food Safety Risk Assessment, Beijing 100020, China
Zhengming Chen
Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford OX1 3QR, UK
Liming Li
Chinese Academy of Medical Sciences, Beijing 100010, China
Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China
for the China Kadoorie Biobank (CKB) Collaborative Group
