Fewer unwed women in the United States are having children, excluding those over the age of 35. 

Nonmarital births have declined by even percent since peaking in the mid to late 2000s, a new report from the Centers for Disease Control and Prevention (CDC) reported. The rates for nonmarital births in women over 35 increased over this time period.

"It's still high compared with previous generations, but there has been a decline," report author Sally Curtin, a statistician at the CDC's National Center for Health Statistics, told HealthDay.

Childbearing in unwed mothers was on a steady incline since the 1980s, but spiked between 2002 and 2007, this new research shows a reverse in that trend, the CDC reported. 

"Since the 1940s, except for a few brief periods, there has been almost a continued increase in non-marital childbearing," Curtin said. "Of all unmarried births, only 15 percent are to teenagers. The majority of these births are in co-habiting unions." 

Births to unmarried women run a higher risk of adverse outcomes such as "low birth weight, preterm birth, and infant mortality," according to the CDC. 

"It's true that in two-parent families, regardless of the gender of the couple, kids tend to do better," Doctor Jill Rabin, co-chief of ambulatory care and women's health programs at North Shore-LIJ Health System told HealthDay. "It's easier when you have a partner raising your child in terms of psychosocial support in addition to the financial benefit," she said. "I do think it takes a village to raise a child."

Births in general have been on the decline in the U.S; they have decreased by 14 percent since the late 2000s. The pattern began during the economic recession in 2007, HealthDay reported. 

"The areas that had the worst economic downturn also had the largest drops in the fertility rate," Curtin said.