According to a new study, women entering their 40s who had their first child out of wedlock experience poorer health, on average, than women who were married when they first gave birth.

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By Carina Storrs
FRIDAY, June 3, 2011 ( — Motherhood can take a toll on any woman's health, but single moms may have an even harder go of it. According to a new study, women entering their 40s who had their first child out of wedlock experience poorer health, on average, than women who were married when they first gave birth—even if they marry in the interim.

Stress and money troubles associated with being a single mom are likely the main culprits, says the lead author of the study, Kristi Williams, PhD, an associate professor of sociology at the Ohio State University, in Columbus. "We know these are much more common among single mothers, and both are strongly implicated in a wide range of health outcomes," she explains.

Since 1979, when the study began, the percentage of U.S. babies born to unmarried women has shot up from 17% to about 40%. The increasing rate of out-of-wedlock births, combined with an aging population, could spell problems for public health, Williams says.

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To make matters worse, the health consequences of single motherhood appear to be surprisingly persistent. The study found that women who gave birth while unmarried reported poorer health later in life even if they eventually married or entered a stable relationship with someone other than the father of their child.

This finding suggests that government programs designed to promote marriage, such as the federal Healthy Marriage Initiative and others like it that emerged from the 1996 welfare-reform legislation, aren't likely to improve public health, the researchers say.

"This study could help us refocus our efforts and to say, 'Clearly, pushing marriage isn't a remedy,'" says Wendy Chavkin, MD, a professor of public health and ob-gyn in the Columbia University Mailman School of Public Health, in New York City, who was not involved in the research.

To promote health among low-income single mothers, Dr. Chavkin adds, the government should focus on providing subsidized child care, increased wages, and better health insurance for working moms—none of which, she says, is provided by "the current welfare apparatus."

In the study, which appears in the American Sociological Review, Williams and her colleagues analyzed data from more than 3,000 single and married mothers who are participating in an ongoing, nationally representative government survey. All of the women gave birth before the age of 36. At age 40, they were asked to rate their current health on a five-point scale from "poor" to "excellent."

Unmarried white and black mothers rated their health lower, on average, than their married counterparts. Hispanic women did not seem to suffer any health consequences from being single moms, possibly because they receive more family support than single mothers of other ethnicities, the study suggests.

Single mothers who went on to marry or live with a partner did not have better health compared with never-married moms, with the exception of white and Hispanic women who eventually married their child's biological father. Black women may not reap any health benefits from marrying their child's father because black men, as a demographic, are less likely to be able to provide the type of financial support that benefits a mother's health, Williams says.

Donna Strobino, PhD, a professor in the Johns Hopkins Bloomberg School of Public Health, in Baltimore, says it is a "no-brainer" that single mothers experience more health problems than paired-off mothers, but she questions how much direct impact single motherhood is having on their health.

Although the researchers controlled for demographic factors such as poverty, education level, and age of childbirth, it's possible that single mothers are more likely than married moms to engage in unhealthy behaviors such as smoking and excessive drinking that could lead to poorer long-term health, Strobino says.

In addition, cultural changes over the past few decades may have weakened the relationship between single motherhood and poorer health. "There has been a trend of both increasing age at childbirth, particularly among white women, and in nonmarital childbirth for all women," Strobino says, adding that women who choose to have children outside of marriage may represent a very different group than the study participants, most of whom likely had unplanned pregnancies.

Williams, however, is skeptical that changing norms regarding unwed mothers will have a significant impact on the link seen in the study. Although waning "social disapproval" of those mothers could potentially play a role, she says, "My guess is that financial strain and child-care responsibility are more important than stigma."

Laura Lindberg, PhD, a senior research associate at the Guttmacher Institute, a nonprofit research organization focused on sexual and reproductive health, says the study highlights the importance of understanding how marriage-promotion programs actually affect the various subgroups of people they aim to help, including low-income single moms.

Much of the research used to support programs like these was conducted in middle-class white couples, Lindberg says. "I think in all policy settings, you want your motivating evidence to be on the population for which you're going to implement the policy."