WEDNESDAY, Dec. 5, 2012 (HealthDay News) -- A new study of couples treated for infertility found a significantly higher death rate among couples who remained childless and lower odds of psychiatric illness among those who adopt.
Researchers in Denmark found death rates were two to four times higher among childless couples, even after taking age, education, income and other health problems into account. Adoption increased longevity and cut the rate of mental illness in half, they found.
"This study finds that men and particularly women who become parents have a decreased rate of death," the study's authors wrote. "Mindful that association is not [the same as] causation, our results suggest that the mortality rates are higher in the childless."
For the study, published online Dec. 6 in the Journal of Epidemiology and Community Health, the researchers examined information on more than 21,000 childless couples in Denmark who underwent assisted reproductive procedures, such as in-vitro fertilization (IVF).
Between 1994 and 2005, they found more than 15,000 children were born and nearly 1,600 couples adopted. During these years, 200 men and nearly 100 women died. And more than 700 women and about 550 men were diagnosed with a mental illness.
The early death rate from cancer, circulatory disease and accidents was four times higher among childless women than women who gave birth to a biological child, the study revealed. Death rates were twice as high for childless men as those who were biological fathers.
The study's authors said the positive effect that becoming parents had on life expectancy applied to adoptive parents as well. The study found that early death rates were cut in half among women who adopted a child. Death rates also were twice as high for childless men as for those who became fathers through adoption.
Although rates of mental illness were similar among biological parents and the childless, the researchers noted that mental illness was about half as common among couples that adopted a child. Their findings suggest the rate of substance use is also higher among the childless, they said in a journal news release.
Previous studies suggested unhealthy behaviors and health issues were to blame for reduced life expectancy among people without children, the researchers noted. They pointed out few other studies distinguished between voluntary and involuntary childlessness.
The authors acknowledge some limitations to their study and said the findings might not apply to others who are childless involuntarily.
The U.S. Centers for Disease Control and Prevention provides statistics on infertility and childlessness.