Birth rates by teenage and young adult mothers in the United States fell to historic lows last year, while birth rates among women over 40 hit a 30-year high, according to data released Thursday.
The birth rate among teens age 15-19 dropped nine percent in 2010 compared to a year earlier, the largest single year dip since 1946-47, the US Department of Health and Human Services said in its National Vital Statistics Report.
At 34.3 births per 1,000 among teens, that marks "a record low for the nation," said the report.
Teenage birth rates have been falling steadily since 1991, and are now 44 percent lower than they were 20 years ago.
"I am aware of no other social problem that has improved so dramatically over so many years," said Sarah Brown, chief executive officer of The National Campaign to Prevent Teen and Unplanned Pregnancy.
"The magic formula of less sex and more contraception is responsible for this great good news."
Tough economic times, combined with some popular reality television shows that have spotlighted the lives of teenage mothers, have also helped bring down the birth rates.
"But at the end of the day, the thanks and admiration go to teens themselves," said Brown.
Women 20 to 24 years old also saw a drop of six percent in birth rate compared to 2009, with 2010's rate of 90 per births per 1,000 making it the "lowest level ever reported for the United States."
Meanwhile, the rate of births among women age 40-44 rose two percent from 2009 to 2010, reaching 10.2 births per 1,000 women, the highest since 1967.
That age group was the only one to see an increase, as part of a trend in which more women in the United States are postponing child-bearing until after they have built their careers.
"Women have more and more options later in life as in-vitro fertilization techniques get better and better," Mitchell Maiman, chairman of obstetrics and gynecology at Staten Island University Hospital, told AFP.
"And of course, more women work, and they delay child-bearing, but now we have the technology to give these women pregnancies well into their 40s, so it is being utilized."
Overall births among women of all races in the United States declined in 2010, and the total number of US births was just over four million last year, dropping three percent from 2009.
The number of Caesarean deliveries leveled off in 2010 (32.8 percent) after a steady rise seen from 1996 to 2009, when they reached 32.9 percent.
"While the C-section rate is still too high, that is a good sign that it is starting to stabilize, at least nationally," said Maiman.
"The rise had to do with a lot of factors -- malpractice in OB-GYN, and doctors practicing defensively, and inductions of labor and not committing to the woman delivering vaginally because of convenience," he added.
"Now there is more education and women are beginning to ask more questions and they realize that having multiple C-sections is not a safe thing for them."
The pre-term birth rate fell for the fourth year in a row to 11.99 percent in 2010, but still remains higher than any year in the span of 1981 to 2001.
