The National Center for Health Statistics released preliminary data for 2012 on births in the United States. While the overall birthrate did not change from the year before, the report found that the rates are stabilizing after years of decline. The report has a lot of other good news: Teen births are down to yet another historic low, births to women in their early 20s also fell to an all-time low, the rate of cesarean sections is stabilizing after years of increasing, and fewer babies were born preterm or at low birth weight. Specifically, the report, which is based on birth certificates filed in 2012, found:

Overall Births

• There were 3,952,937 babies born in the United States in 2012. This is similar to the number of births in 2011, but marks a change from previous years, as the number of births declined steadily between 2007 and 2010.
• The number of births to non-Hispanic Black women as well as American-Indian or Alaska Native women was unchanged, while births to non-Hispanic white and Hispanic women were down slightly at 1 percent. In contrast, births to Asian or Pacific Islander women rose by 7 percent.
• The general fertility rate was down slightly (1 percent) from the previous year, dropping to a record low of 63 births per 1,000 women ages 15 to 44.

Births to Teenagers

• The birthrate to teenagers fell 6 percent from 2011, reaching a new historic low of 29.4 births per 1,000 teenage women ages 15 to 19. Overall, the rate has dropped more than half since its high of 61.8 per 1,000 teenage women in 1991 and by a third since 2007 when it was at 41.5 per 1,000 teenage women.
• In 2012, there were 305,420 births to teenage women ages 15 to 19; this is the fewest births to this age group since the end of World War II.
• Births to younger teens fell 8 percent to just 14.1 births per 1,000 teen women ages 15 to 17. This represents a 63 percent decline since 1991. Rates for older teens fell by 5 percent to 51.4 births per 1,000 teen women ages 18 and 19. This represents a 45 percent decline since 1991.
• Birthrates fell among teenage women ages 15 to 19 in all ethnic and racial groups between 2011 and 2012.
• The birthrate among Hispanic teenagers has dropped the most since 2007 (39 percent), to 46.3 births per 1,000 in 2012.
• The birthrate for women ages 20 to 24 has been falling by about 5 percent each year since 2007. Between 2011 and 2012, the birthrate to women in their early 20s dropped 3 percent, to 83.1 births per 1,000 young women, which represents another historic low for the nation.

Health Outcomes

• In 2012, 32.8 percent of newborns were delivered via c-section. This rate is unchanged since 2010, but follows more than a decade of steady increase—the c-section rate rose nearly 60 percent between 1996 and 2009.
• The rate of cesarean delivery, however, was not the same across racial and ethnic groups. While it declined for the third consecutive year among non-Hispanic white women, the rates among non-Hispanic Black and Hispanic women were at the highest levels reported since 1989 (the first year for which data on this was collected).
• In 2012, 11.54 percent of births were considered preterm, meaning that the infant was delivered at less than 37 weeks’ gestation. This represents a 2 percent decline from 2011 and a 10 percent decline form 2006. Before that—between 1981 and 2006—the percent of babies born preterm rose by more than a third.
• Though the preterm birthrates differs by ethnic and racial groups, no groups experienced a rise between 2011 and 2012. Rates were “essentially stable” for Hispanic and American-Indian/Alaska Native infants and fell for non-Hispanic white, non-Hispanic Black, Black, and Asian or Pacific Islander infants.
• The rate of preterm births among Black infants is higher than in other ethnic groups, at 16.53 percent in 2012, but still represents an all-time low since this data began being collected in 1981.
• In 2002, 7.99 percent of babies were considered low birthweight (born at less than 5 pounds, 8 ounces). This represents a 1 percent decline from 2011 and 3 percent decline from the 2006 peak of 8.26 percent.

The data cannot explain why birthrates are dropping in general or among particular groups, but public health experts, demographers, and economists have suggested numerous possible reasons. Public health experts point to increased use of birth control and, in particular, increased use of better methods of contraception such as intrauterine devices (IUDs) and contraceptive implants, which have very low failure rates. Economists add that financial struggles and joblessness have also played a role in individual’s decisions about starting or increasing the size of their families.

John Santelli, a professor at Columbia University‘s school of public health told NBC News that a combination of factors likely affected these numbers. “People are starting families later and later, and these are historical changes and happening worldwide,” he said. “The last downturn in the economy has accelerated the trend.”

Some demographers, however, think that the birthrates have bottomed out and will climb again soon. Sam Sturgeon, president of Demographic Intelligence, said in a statement, “We think that this fertility decline is now over. As the economy rebounds and women have the children they postponed immediately after the Great Recession, we are seeing an uptick in U.S fertility.” And, Kenneth Johnson, a demographer at the University of New Hampshire, told CNN Money, “In the 2012 data, you’re seeing what women were thinking about in 2011. If the economy were to be picking up now, you’re not seeing that in the birth patterns yet. It will be another year until you’ll see the effect of that.”