Age really is just a number.

More and more, women are planning to have children later in life. That's not just a casual observation, it's a fact: Data shows that the number of women having babies after age 35 is continuing to grow. And celebrities are certainly no strangers to this concept. From Halle Berry and Mariah Carey to Celine Dion and Molly Ringwald, plenty of popular artists, actresses and entertainers decided to become a mom later in life.

With Janet Jackson's "family planning" announcement earlier this morning (April 6), we went back to highlight other celebrities who have given birth after their 39th birthdays.

Scroll through the gallery of 25 stars above who had kids at 40.