Unwed motherhood is way up, primarily because women in their 20s and 30s don’t see marriage as essential or because single women nearing 40 prefer a sperm donor to a marriage of convenience. Nearly four of 10 babies are born out of wedlock, up from one third in 2002 and double the 1980 rate.

“It’s been a huge increase — a dramatic increase,” said Stephanie J. Ventura of the National Center for Health Statistics, which documented the shift in detail.

. . . “I think this is the tipping point,” said Rosanna Hertz, a professor of sociology and women’s studies at Wellesley College. “This is becoming increasingly the norm. The old adage that ‘first comes love, then comes marriage, then comes baby in the baby carriage’ just no longer holds true.”

The unwed birth rate is highest for Hispanics at 106 births to per 1,000 unmarried women; the rate is 72 per 1,000 blacks, 32 per 1,000 whites and 26 per 1,000 Asians.

European rates are even higher: 66 percent in Iceland, 55 percent in Sweden, 50 percent in France and 44 percent in Britain.

About 40 percent of unwed mothers live with the baby daddy, at least at first, earlier research shows.

(Heidy) Gonzalez, the mother who lives with her children’s father in Mount Rainier, said marriage has not loomed as a necessity for them. “Time goes by and we think about other stuff — and we think about rent,” she said. This holds true, she said, for most of her friends. “Most of the people I know just live with their baby’s father or boyfriend and don’t get married,” she said.

When the going gets tough, unwed fathers often find it easy to leave the relationship — and the kids. Divorced dads have a much better record of involvement with their kids than never-married dads.

There’s little or no stigma in unwed motherhood. But it remains a bad deal for the mothers and a very bad deal for their children, who are much more likely to grow up in poverty and without a father’s love and care.

In New Carrollton, Natrice McKenzie, 25, a teller supervisor at a bank, said she did not set out to become a single mother but has no regrets.

“Getting married was something I had in mind, but that basically was not what happened,” said McKenzie, pregnant with her third child.

Something else didn’t happen either: birth control. I can understand one unplanned pregnancy. But three by the age of 25?