The experts considered the increase in birth rate in older mothers are also important.
"That teen births declined 9 percent in one year is incredible", said Dr. Elise Berlan, who runs the Young Women's Contraceptive Services Program at Nationwide Children's Hospital in Columbus, better known as BC4Teens.
According to the Centres for Disease Control and Prevention's provisional 2016 population data, the number of births this year, in comparison to last year, fell about 1 percent, which brought the fertility rate in the USA down to 62 births per 1,000 women between the age of 15 to 44.
Over the past two decades, birth rates among teens are down by almost 65%, while more than doubling for women over 40. There's also more births compared to deaths. The researchers have found 1 percent increase in birth rate for the females between the ages of 30 and 34 since 2015 which is considered ad the highest birth rate for women between ages of 30 and 34 since 1964 while the birth rate for women between 35 and 39 show over 2 percent increase from 2015 which is also the highest birth rate since 1962.
"The CDC has called (teen pregnancy) a 'winnable battle, '" Berlan said.
Jarris added that more teens are using long-lasting birth control, like implants and intrauterine devices (IUDs), which have helped to teen birthrates dropping and make unintended pregnancy less likely.
"For seven years, we had improvements in preterm births in this country, and now after years of improvement we are getting worsening conditions for moms and babies", said Jarris, according to CBS News.More news: Nobody is indispensable - Figo thinks Real Madrid could cope with Ronaldo exit
New data released Friday revealed the number of women giving birth in the United States has hit a historic low, causing some to fear that the country is heading toward a "national emergency".
Preterm birth and the conditions associated with it are the largest killers of children up to age 5 in the world, said Jarris.
"So not only are we getting worse as a nation, we are getting less equitable as a nation", Jarris said.
For women between ages of 40 and 44, births increase of 4% over 2015 - the highest rate for this group since 1966.
More than three-quarters of pregnant women started essential prenatal care in the first trimester.
For the fourth year in a row, the number of cesarean deliveries declined slightly, falling to just below 32 percent of births.
However, people should not be alarmed because of the low fertility rate in the US.