Updated

The teen pregnancy rate is up for the first time since 1991, while the percentage of teens who smoke has hit a 10-year low, according to a report released Friday by the National Institutes of Health.

Between 2005 and 2006, the number of teenage girls between the ages 15 to 17 having babies rose by more than 5,700 to 138,920, from a record low of 133,138, according to an annual report on the health and well-being of children and teens published by the Federal Interagency Forum on Child and Family Statistics.

The 4 percent increase in the teen pregnancy rate is cause for concern among health professionals.

“This is one of the key indicators for the health of the teen population,” said Edward Sondik, director of the National Center for Health Statistics, during a conference call with the media. “Not only does this affect teen health at this point, but their health and well-being for the next 20 to 40 years, and the health and well-being of their children.”

About 22 out of every 1,000 girls ages 15 to 17 became pregnant in 2006, compared to 21 out of every 1,000 in 2005. The pregnancy rate hit an all-time high of 39 births per 1,000 teens in 1991 and then steadily declined until 2006.

Teen pregnancy has been a hotly debated subject in recent weeks with the birth of 17-year-old Jamie Lynn Spears’ daughter and reports that a pact among Gloucester, Mass., teens may have resulted in the pregnancies of 17 high school students.

Dr. Keith Ablow, a psychiatrist and FOX News contributor, said the recent reversal in the trend of declining teen pregnancy is a grave concern. He said young people, especially girls, are looking for ways to connect with themselves and others in an “increasingly technology-driven world.” One way to do that is to have a baby.

“It’s not pretty and we really need a public health response that’s very vigorous to counteract this,” he said. “Ultimately, the gravest long-term consequence is that we have babies being nurtured by mothers who really can’t provide them with what they need.

"And that’s really a self-centered act. You’ve basically declared that it’s all about you. Those people who are [acting] in this way may be the worst role models.”

While teen pregnancy is up, the percentage of teens having sex has remained stable for the past few years at 46 percent, according to the report.

The annual study also pointed to declines in teen smoking over a 10-year period.

In 2007, 3 percent of eighth-grade students reported smoking cigarettes daily over the past 30 days — down from 4 percent in 2006 and significantly below the 1996 high of 10 percent. Last year, 7 percent of 10th-graders and 12 percent of 12th-graders reported smoking cigarettes daily, unchanged from 2006 but down from the groups’ respective highs of 18 percent and 25 percent in 1996 and 1997.

Sondik attributed the decline in smoking to increased education, widespread smoking bans and legislative increases in cigarette taxes.

“Teens are making the right choices in their early lives and we certainly hope that’s a trend that will remain,” said Sondik, adding that he is concerned that smoking among 10th- and 12th-graders isn’t declining as quickly as it is with eighth-graders.

“I’ve always been struck by the fact that efforts to reduce smoking applied to the adult population have lasting effects, but when it comes to kids, the time to influence them is very short,” he said. “We have to continue with our education and incentives if we want to continue to see change.”

Other highlights of the study include:

— The number of babies born to unwed mothers continues to increase. In 2006, 38 percent of all births were to unmarried women, up from 37 percent in 2005. The percentage of children under age 18 living with two married parents fell from 77 percent in 1980 to 68 percent in 2007. The percentage of unmarried births to women in their 20s tripled, from 19 to 58 percent for women ages 20 to 24 and from 9 to 31 percent for women ages 25 to 29. The percentage of births to unmarried women in their 30s more than doubled from 8 to 18 percent

— The percentage of low birth-weight babies has increased for more than two decades. In 2006, 8.3 percent of infants were born low birth weight, up from 8.2 percent in 2005, 8.1 in 2004, and a low of 7.0 in 1990. An increase in multiple births, maternal birth age and changing obstetric interventions have contributed to this trend, Sondick said.

— In 2005, injury deaths among adolescents ages 15 to 19 were 50 deaths per 100,000 adolescents, a decrease from 51 deaths per 100,000 in 2004, mostly due to a decrease in motor vehicle deaths, Sondik said.

Click here to see the full study.

The Federal Interagency Forum on Child and Family Statistics compiles the report from statistics and studies at 22 federal agencies. The report covers 38 key indicators of “child well-being,” including infant mortality, health, behavior, academic achievement and the number of children living in poverty.