More New York women are waiting until later to have their first child, according to government data released Friday.
New York was second in the nation, behind Washington, D.C., for the number of women having their first child between the ages of 40 and 44. For women who first give birth between age 35 and 39, New York is third, behind Massachusetts and D.C.
The Centers for Disease Control data show the same trend nationwide, with the average age of women when they first give birth rising over the past 40 years.
The rate of women having their first child after 40 more than doubled from 1990 to 2012, the CDC said. And in 2012, there were more than 9 times as many first births to women 35 and older than 40 years ago.
In New York, the rate has gone up 57 percent between 2000 and 2012, the CDC said.
Elizabeth Gregory, director of Women's, Gender & Sexuality Studies at the University of Houston, and author of "Ready. Why Women Are Embracing The New Later Motherhood," told NBC News there are a number of factors contributing to the change. Those include women getting married later and spending more years on their education and careers.
"Many of these women took time to finish their educations and establish themselves at work," she said. "Women figured out early on there is a financial return to delay, and they could provide for their families better."
The CDC says older mothers are generally better educated and have higher incomes, but there are also higher health risks to moms giving birth over 40.