Given that cohabiting before marriage correlates with divorce, and that many cohabiting couples express “ambivalence” about having a child, this trend seem ominous to me, both for the potential marriage and for the actual child.

The report found that about 37% of births in the USA were unintended at the time of conception, a percentage that hasn’t changed since 1982. The proportion of unintended births declined among married white women, but those accounted for a smaller proportion of births. Meanwhile, births to single or cohabiting women rose.

The report also reveals more details about contraception. In 2008, for example, 19% of births were unintended; 36% of women who had an unintended birth said they didn’t use contraception because they thought they couldn’t get pregnant. But 23% of those women said they “didn’t really mind if I got pregnant.”

“A lot seems to have to do with the fact people are increasingly ambivalent about whether or not to have a child,” says Karen Guzzo, a sociologist at Bowling Green (Ohio) State University. “They’re in this committed relationship and are often cohabiting and not trying hard to avoid having a child, but they’re not trying to have one, either.”