Nearly 4.1 million babies were born in the U.S. last year, boosting the nation’s birth rate by 4 percent from 2003.

The numbers come from the CDC. The CDC also reports that birth rates dropped for younger women and rose for older and unmarried women.

Here’s a quick look at the latest trends noted by the CDC.

Myths, Dos and Don'ts for a Healthy Pregnancy

Teenage Birth Rate Hits Record Low

The birth rate for teens has never been lower. It’s been dropping for a while, but the pace is cooling off, the CDC reports.

Consider the CDC’s numbers:

—Birth rate: 41.2 babies per 1,000 women age 15-19 years

—1 percent lower than the 2003 rate for that age group

—33 percent lower than the 1991 birth rate for that age group

Birth rates for women age 15-17 years and 18-19 years “declined modestly,” says the CDC.

The birth rate for those age 10-14 years rose “slightly,” says the CDC. Still, births were rare for that age group. They had less than one baby per 1,000 females.

Who Had the Highest Birth Rate?

Women in their late 20s still have the highest birth rate of any age group.

Their birth rate didn’t change in the past year. In 2004, about 115 babies were born per 1,000 women age 25-29 years.

Slightly younger women — those in their early 20s — had a small (1 percent) drop in their birth rate. In 2004, nearly 102 babies were born per 1,000 women age 20-24 years.

More Older Moms

Births to older women continued to increase. The biggest jump was among women in their late 30s, followed by women in their early 40s.

Here’s the breakdown:

—Women age 30-34: birth rate up less than 1 percent (95.5 births per 1,000 women)

—Women age 35-39: birth rate up 4 percent (45.4 babies per 1,000 women)

—Women age 40-44: birth rate up 3 percent (9 babies per 1,000 women)

Births were much more rare for women in their mid-40s to mid-50s. They had less than one baby per 1,000 women.

Late Motherhood Emerges

Birth Rate Rises for Unmarried Women

The birth rate for unmarried women hit an all-time high last year.

In 2004, nearly 1.5 million babies were born to unmarried women. That’s nearly 36 percent of all babies born last year — a 4 percent increase from last year.

Those numbers don’t show if the women were in a committed relationship (without being married).

Births to unmarried women have generally risen since at least the 1980s, according to the CDC’s report.

By Miranda Hitti, reviewed by Louise Chang, MD

SOURCES: CDC, “Preliminary Births for 2004.” News release, CDC.