The government reports four out of 10 babies born in the U.S. in 2007 were born to unwed mothers.
The rate has doubled since 1980, and that's raising some serious concerns.
Tiere England, 21, loves her baby girl -- and like many women her age she does not have a husband.
"If it happens it happens. I'm not planning on it.or excited about it," England said.
It is a trend among women in their early 20's -- having children without the benefit of marriage.
Since 2002, the number of unwed teen mothers has been steady or on the decline -- while the number of single women over 20 having babies is up 13 percent -- and the number of unwed mothers in their 30's is even higher -- 34 percent.
"These aren't women running to the sperm bank with an empty cup in their hand, these are woman who may be in relationships," said pediatrician Dr. Taisha Benjamin. "For the majority of them they are unplanned pregnancies."
Like England, many single moms are in no rush to tie the knot.
Christian leader Bishop T.D. Jakes says that's because marriage is no longer valued in today's culture.
"Marriage is going out of style in our country. We're losing the number. People are not getting married or they're getting out of marriage more quickly -- they're waiting later to get married and the whole idea of marriage is eroding," Jakes said.
Women who forego marriage don't necessarily raise their babies alone. One study shows about half of unwed mothers live with their children's father.
"So in many senses they look a lot like married parent families - two parents to share in the child care, two parents to share in expenses, two parents to share in housework," Kelly Musick said.
England says she and baby are all the family she needs.
Jakes says its attitudes like that which threaten the institution of marriage.
"People believed in marriage -- today, they're losing their ideology around marriage altogether, and I think that's going to be very detrimental in the long term."
Experts say the social stigma against out-of-wedlock births has subsided -- giving way to a greater emphasis on stable long-term relationships -- married or not.