Association between the number of live births and estimated life
expectancy
We estimated the lower or higher survival time (years) due to the
different parities, as shown in Figure 1. At age 40, childless women had
an average 1.41 (95% CI: 0.78–2.01) lower years of life expectancy,
and women with two, three, or four had an average 1.10 (95% CI:
0.63–1.74), 1.00 (95% CI: 0.54–1.74), and 1.00 (95% CI: 0.05–1.84)
higher years of life expectancy, respectively, as compared with women
who had one child. The corresponding lower years of life expectancy at
the age of 60 years were 1.20 (95% CI: 0.66–1.71) years in unproduced
women, and the corresponding higher years of life expectancy at the age
of 60 years were 0.97 (95% CI: 0.56–1.52), 0.88 (95% CI: 0.48–1.52),
and 0.79 (95% CI: 0.05–1.61) years in women who gave two, three, or
four births, respectively.