Pregnancy and abortion rates in the United States have hit record lows, according to new data released on Friday.

Births and abortions were both down over the same time in 2010, based on the latest research conducted by the National Center for Health Statistics (NCHS) and the Guttmacher Institute, NBC News reported.

"The pregnancy rate for women in the United States continued to decline in 2010, to 98.7 per 1,000 women aged 15-44, a record low for the 1976-2010 period. This level was 15 percent below the 1990 peak," wrote researchers Sally Curtin and Joyce Abma of the NCHS and Kathryn Kost of the Guttmacher Institute.

They added, "The estimated number of pregnancies dropped to 6.155 million in 2010, the lowest number since 1986."

The study said the decline in the overall pregnancy rate during 1990–2010 included reductions in birth and abortion rates, with the percent decline greater for abortions (35 percent) than births (10 percent) over this period.

The researchers calculated that the 2010 abortion rate (17.7) was a record low and foetal loss rates fluctuated over the period and were 3 percent lower in 2010 than in 1990.

"The estimated number of pregnancies dropped to 6.155 million in 2010, the lowest number since 1986. Pregnancies in 2010 included 3.999 million (65.0 percent) live births, 1.103 million (17.9 percent) induced abortions, and 1.053 million (17.1 percent) foetal losses," they said.

The survey used 2010 data as it's the latest available for the kind of analysis the researchers did. Another study by the Centers for Disease Control and Prevention showed that birth rate rose by 1 percent in 2014, the first increase in seven years, mainly because of older mothers giving birth, NBC News added.

According to the new research, compared with 1990, pregnancy rates were lower in 2010 for women under age 30, with the largest percent decline occurring among teenage subgroups, including a 67 percent decline for teenagers aged 14 and under, and a 50 percent reduction for teenagers aged 15-19.

Pregnancy rates in 2010 were highest for women aged 25–29 (157.1 per 1,000 women) followed by women aged 20–24 (144.6), with declines of 12 percent and 27 percent, respectively, since 1990. Rates for women aged 30 and over increased over the 20-year period, with women aged 40 and over having the largest percent increase (70 percent). However, rates for women in their 30s have declined since 2006–2007.

Other studies showed that more teens use contraceptives and fewer teens are having sex, which contribute to having record low rates for teen births.

Guttmacher researchers in other studies have found that half of the pregnancies in the U.S. are unintended and that teens do not use the most effective methods of birth control and use condoms instead of implantable birth control drugs.

U.S. teenage birth rate is still seven times higher than in other rich countries, according to federal data.