Living together before going to the altar increases the risk that the marriage will fail, says a U.S. study.
Their analysis of data from the National Survey of Family Growth in 2002 found that a marriage was 6 percent less likely to last 10 years if a couple lived together before they tied the knot, The New York Times reported.
The study by researchers at the National Center for Health Statistics also found that the proportion of women in their late 30s who had ever cohabited had doubled in 15 years, to 61 percent.
Among the other findings:
* Half of couples who cohabit marry within three years.
* If both partners are college graduates, it's more likely that they'll marry and that their marriage will last at least 10 years.
* Couples who marry after age 26 or have a baby eight months or more they get married are also more likely to stay married for more than 10 years.
* About 62 percent of women ages 25 to 44 were married and 8 percent were cohabiting. Among men, figures were 59 percent and 10 percent, respectively.
* Overall, one in five marriages will fail within five years. One in three will last less than 10 years.
"Cohabitation is increasingly becoming the first co-residential union formed among young adults," wrote the study authors, The Times reported... "As a result of the growing prevalence of cohabitation, the number of children born to unmarried cohabiting parents has also increased."