Send to

Choose Destination
J Epidemiol Community Health. 2018 Apr;72(4):337-341. doi: 10.1136/jech-2017-209809. Epub 2018 Jan 9.

U-shaped association between fertility and mortality in a community-based sample of Japanese women.

Author information

Department of Human Ecology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Department of Anthropology, University of Washington, Seattle, Washington, USA.
Department of Pediatric Infectious Diseases, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
National Institute of Environmental Sciences, Tsukuba, Japan.



Prospective cohort studies of contemporary populations in both Western and Asian settings have reported a U-shaped association between fertility and mortality. We examined whether an association exists between fertility and all-cause and cause-specific mortality in a sample of Japanese women.


A prospective cohort study was conducted in one rural and one urban community in Gunma Prefecture, Japan, in 1993. A follow-up survey was conducted in the year 2000 in 4858 women aged 47-77 years, and information on demographic and lifestyle characteristics was collected. Mortality and migration data through December 2008 were obtained. A Cox proportional hazard model was used to examine the relationship between parity and mortality.


Compared with women with 2-4 children (reference group), higher total mortality was observed among women with 0-1 or 5+ children. Low (HR 1.7, 95% CI 1.2 to 2.3) and high (HR 2.1, 95% CI 1.0 to 4.7) parities were both associated with higher all-cause mortality even after adjusting for potential confounders. Mortality due to ischaemic heart disease exhibited a significant association with parity; the HRs were 3.2 (95% CI 1.1 to 9.2) for women with 0-1 child and 8.7 (95% CI 1.7 to 45.5) for women with 5 or more children. No significant association was observed for mortality from malignancies, cancer of the digestive system, cardiovascular disease or cerebrovascular disease.


There exists a U-shaped association between parity and all-cause mortality and cause-specific mortality due to ischaemic heart disease among Japanese women.


cohort studies; fertility; ischaemic heart disease; mortality


Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center