Couples who choose to have their own children or adopt live longer than couples who don't have kids, an effect especially seen in women, a new study shows. Mental health status was also better for adoptive parents.

Researchers looked at data in Denmark on births and deaths from 1994 to 2008. Mothers with a biological child were four times less likely to die an early death than childless women. Fathers with a biological child were two times less likely to die an early death than childless men. Men who adopted were nearly half as likely to die early as men who had no children. For women, the effect of adoption on longevity was not significant.

Researchers said the link may show that when people have kids, they tend to live healthier.

Read more from WebMD.