Women who become single mothers between the ages of 16 and 49 are more likely to have poorer health later in life, according to a recent study.

Research published in the the Journal of Epidemiology & Community Health collected and "analyzed data from 15 different countries and found that the health risks appeared to be greatest for single mothers in the United States, England, Denmark and Sweden," Medical News Today reported.

In the study, single motherhood was classified as having a child under the age of 18 and not being married rather than living with a partner.

The researchers base their findings on the responses of more than 25,000 women aged 50 years and older to questions about childbearing and marital status; any limitations on their capacity for routine daily activities (ADL), such as personal hygiene and getting dressed, and instrumental daily activities (IADL), such as driving and shopping. They were also asked to rate their own health.

One in three of the U.S. mums surveyed had been a single mother before the age of 50, compared with around one in five in England and Western European countries, around four out of 10 in Denmark and Sweden, and one in 10 in Southern Europe.

Based on their analysis, any period of single motherhood was linked to a greater risk of some level of physical disability and poor health in later life than dual parenthood. But the associations were stronger for single mums in England, the US, Denmark and Sweden. Single motherhood was less consistently associated with health in Western, Eastern, and Southern European countries.

Their findings indicated that women who became single mothers before the age of 20, or as the result of divorce, or who parented alone for 8 or more years, or who had two or more children, were at particular risk of disability and poor health in later life.

"The findings add to the growing recognition that single motherhood may have long term health effects on mothers. As lone motherhood is on the rise in many countries, policies addressing health disadvantages of lone mothers may be essential to improving women's health and reducing disparities," they write.

Researchers believe that adequate access to contraception and policies that help single mothers to stay in the workforce and help them balance the demands of work and family may be very helpful.