Hilary Swank announces she is pregnant with her third child at 52

Hilary Swank has surprised fans with a big announcement: She is pregnant with her third child at the age of 52, after having twins at 48.

The "Million Dollar Baby" star and her family shared the news on social media with a video showing them dancing with glowsticks taped to their bodies, which then revealed the mom's baby bump.

The caption reads, "A lot of people have been asking what project I'm doing next, this one releases in December."

Three years ago, the Oscar winner gave birth to twins, daughter Aya and son Ohm, with her husband Philip Schneider, who is also 52.

Dr. Kameelah Phillips, OB-GYN, said it's "extremely rare" to be pregnant at 52, and that it comes with serious medical considerations.

"Most women in this age group are entering menopause," she said. "But ... even if your ovaries have started to become quiet ... your uterus can actually be convinced to carry a pregnancy through the process of IVF."

"She's definitely probably being seen by a high-risk team," said Phillips. "For moms, they have the increased risk of gestational hypertension, preeclampsia, diabetes, increased risk of C-section."

Swank spoke to "CBS Sunday Morning" two years ago, after the birth of her twins.

"I think for me being a parent who is on the older side, the beauty in it for me has been that I had the opportunity to dive deep into this dream of being an actor and now I can dive deep into this dream of being a mom because I'm not pulled in any other direction," she said.