Having Kids Before Marriage Doesn't Raise Divorce Odds Anymore
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Unwed parents were once more likely to get divorced than couples who got married before having kids. Not anymore, a new study shows.

Family structure and societal taboos have changed over the years, and now couples who have kids before marriage have no higher chance of divorce than couples who have kids after marriage, the researchers said.

"There's less social pressure now to marry [before having children]," said study researcher Kelly Musick, an associate professor of policy analysis and management at Cornell University in New York. "Couples are establishing their relationships and maybe considering marriage, but not worrying so much about marriage before starting a family." [5 Facts About Couples Who Live Together]

The new research relied on data about couples who had children between 1985 and 1995 (the earlier period) and 1997 and 2010 (the later period), who were part of the National Survey of Family Growth run by the Centers for Disease Control and Prevention. Participants in the survey — women of childbearing age in the United States — answered questions about their relationships and family formation. (The researchers looked only at surveys from 1995 and from 2006 to 2010, and included women who had children within 10 years of each survey.)

The researchers examined survey responses from cohabitating or married couples with kids, giving them a sample of 2,656 couples from the earlier period and 3,046 from the later period.

In the earlier period, 17 percent of the couples had children before marrying. Of these, 21 percent married within a year, and 59 percent went on to marry within five years of having kids, the researchers said. In the later period, twice as many couples, or 35 percent, had kids out of wedlock. What's more, fewer of them married after having kids: 15 percent married within a year and 48 percent married within five years, the researchers found.

Divorce rates were high among the earlier group, they found. Couples who lived together, then had children and later married were more than 60 percent more likely to divorce than couples who got married and then had kids.

Surprisingly, this effect disappeared in the later group, even after the researchers controlled for socio-demographic factors that are tied to marital behaviors and risk of divorce, such as race, education levels and whether or not the participants lived with both biological parents until age 18, they said.

However, one group did not fare well in the later group. Cohabitating parents who never married were more likely to separate than married couples. About 30 percent of these couples separated within five years of having kids, a breakup rate twice as high as the married couple rate during that period, the researchers found.

"This is a disturbing finding in terms of child outcomes, because we know that family instability is a risk factor for children," the researchers wrote in the paper.

Why the change?

It is anyone's guess why divorce rates have dropped among couples who have kids before marriage, but the researchers have several ideas. For instance, more couples in the United States are living together before marriage, and some of these couples may have children before tying the knot, they said.

"The increasing stability of relationships involving cohabitation and the declining importance of marriage timing relative to parenthood is consistent with waning social pressure to marry and the blurring of boundaries between marriage and cohabitation," Musick told Live Science. [I Don't: 5 Myths About Marriage]

Moreover, people tend to have high standards for whom they marry, and may hold off on marriage until a number of other prerequisites fall into place, including being economically stable and having a decent job and place to live.

Even if they have children together, "some couples may hold off until those pieces are in place," Musick said. "They've got marriage on the back of their minds, but wait to take that step until they feel they've met these pretty high standards."

The findings were detailed Wednesday (Sept. 16) as a briefing paper for the Council on Contemporary Families. The full results will be published online Sept. 18 in the journal Demography.

Follow Laura Geggel on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.