Baby Girl Playing Dress-up
Credit: Constance Bannister Corp/Getty Images

It used to be easy to look at a birth announcement and know that when the child was named Ezra, Max, or Jackson, the family had welcomed a baby boy. Nowadays, though, little baby Jackson or Ezra just might be a girl. As grandma used to say with a big shrug: Kids these days!

As Today reports, more and more parents are shaking up gender norms when it comes to naming their children. What even a few years ago were traditionally boys' names increasingly are being used for little girls. For example, in 2015, 237 baby girls were named Spencer, while there were 205 Ezras, 202 Tylers, and 137 Noahs. There were even a handful of girls named David and Oscar.

The trend isn't entirely new—don't forget that even amateur detective Nancy Drew's best friend was named George—but seems to be picking up speed. This could be in part because celebrities are helping to make names appear more unisex. One of the lead characters in the popular TV series, Pretty Little Liars, was a girl named Spencer and don't forget that Phoebe Cates's character in Shag was named Carson. In 2015, 177 other little girls were named Carson, too, perhaps by parents raised on Shag.

Of course, in the South the rise could be attributed to family names popping off the family tree and into birth certificates. Little girls have been given names like Lincoln, Jackson, Uriah, Barrett, Maddox, Paxton, and Lamar, which certainly sound like they could belong to great-grandparents.

Some names that used to be unisex became associated with only one gender. For proof, look no further than Gone with the Wind's Ashley Wilkes. Few boys are named Ashley these days despite having that illustrious role model.

WATCH: Vintage Baby Names

So far, the trend doesn't seem to work both ways, though, and no one has written about little boys being named Sarah or Lily—yet.

That said, the next time you receive a birth announcement, look for hints like "son" or "daughter" before sending a present—or skip the whole thing and buy everyone a copy of Goodnight Moon.