In The US, the average age of first-time mothers has reached all-time high, over 26. TJ Mathews of the Centers for Disease Control and Prevention said that the change has come mainly because of a big fall in teen moms. However, more first births to older women have been also tugging the number up.

TJ Mathews is the main author of a report released on Thursday that has placed the average age at 26 years, 4 months for women who delivered their first baby in 2014.

Around 1970, the government started tracking the age of new mothers, and that time the average was 21. Since then, the number has been climbing, and spiked in about previous five years.

Following a 1973 US Supreme Court ruling that legalized abortion, the number rocketed immediately. Abortion is mostly used by young unmarried women. Experts said that factors like improvements in birth control and greater opportunities for women also fueled the rise.

John Santelli, a Columbia University professor of population and family health, said, “Women are staying in school longer, they’re going into the workforce, they’re waiting to get married, and they’re waiting to have kids. It’s been going on in the US since the 1950s,” and in many other countries as well”.

As a whole, the average age of first-time moms has shown a rise in each and every racial and ethnic group, and in every state. Since 2000, black mothers living along the West Coast were accountable for some of the most dramatic increases.

But still, the Northeast has the highest average ages. On the top of the list are Massachusetts and the District of Columbia, both at about 29, and then Connecticut and New York, at or around 28.

Older moms are common in New York’s Park Slope neighborhood in Brooklyn, which is an enclave for families having young children.