Association between the number of live births and hazard of cause-specific premature mortality
The results of the multivariate Cox proportional hazard regression models between the number of live births and hazard of cause-specific premature mortality are presented in Supplementary table 3. We documented 1552 incident cases of premature mortality of cardiovascular disease (CVD) and 6878 incident cases of cancer-specific premature mortality during follow-up. After adjustment for multiple covariates, compared with the reference group, we found that the women with two, three and four childern had lower risk of CVD-specific premature mortality (HR2=0.69, 95% CI: 0.60-0.80, HR3=0.71, 95% CI: 0.60-0.84, HR4=0.78, 95% CI: 0.62-0.99); the female who gave two or three births had lower risk of premature mortality of coronary heart disease (CHD) (HR2=0.71, 95% CI: 0.55-0.91, HR3=0.68, 95% CI: 0.51-0.91) and the female with three childern had lower risk of stroke-specific premature mortality (HR3=0.66, 95% CI: 0.48-0.91). Compared to the reference group, the childless women had higher risk of cancer-specific premature mortality (HR0=1.16, 95% CI: 1.07-1.27); the women with four childern had lower risk of premature mortality of breast cancer (HR4=0.55, 95% CI: 0.39-0.79); the female without childbirth history had higher risk of premature mortality of ovarian cancer (HR0=1.37, 95% CI: 1.02-1.83), and the female who gave three births had lower risk of premature mortality of ovarian cancer (HR3=0.71, 95% CI: 0.52-0.98); and the women with five or more children had higher risk of premature mortality of cervical cancer (HR5=8.01, 95% CI: 1.08-59.60).