Brigitte Nielsen posted images with the news on Instagram.
Actress Brigitte Nielsen, 54, is pregnant.
The Red Sonja actress, once married to Sylvester Stallone, shared the news to Instagram on Wednesday morning, with a photograph of herself dressed in a white dress as she placed her hands on her large baby bump, the Daily Mail reported.
The '80s icon wrote in her caption, "Family getting larger." Nielson has been married to Italian TV producer Mattia Dessì, 39, since 2006.
Soon after she posted a second photo, this time with the caption, "Happy time. Positive vibes." She wore sunglasses and a scarf with a tight T-shirt dress.
This is the fifth child for the movie star who is best known for 1985's Rocky IV, 1986's Cobra and 1987's Beverly Hills Cop II. She already has sons Julian, 34, Killian, 28, Douglas, 25, and Raoul, 23.
Nielsen was previously married to Raoul Meyer from 1993 to 2003, Sebastian Copeland from 1990 until 1992, Sylvester Stallone from 1985 until 1987 and Kasper Winding from 1983 until 1984.
Mattia is her fifth husband.
She has also dated Flavor Flav (2003 - 2005), Mark Gastineau (1988 - 1990), Tony Scott (1987), Kelly Sahnger (1987 - 1988) and Arnold Schwarzenegger (1984 - 1985). And she has been linked to Vanilla Ice, Mick Hucknall and Sean Penn.
She and current husband Mattia never shy away from public displays of affection, and are often seen cosying up to each other at events.
The pregnancy comes as a shock to fans that have not seen a hint of a baby bump in the past. She has been skillful at hiding her midsection in the past several months.
In the new images, she appears to be more than eight months along.
Nielsen is not along in her choice to have a child later in life. In 2013, 13 babies were born each week to mothers aged 50 and older, according to parenting.com.
The Centres for Disease Control and Prevention says births by women between the ages of 50 and 54 increased by more than 165 per cent from 2000 to 2013.
Most women who get pregnant at age 50 do so with the help of in vitro fertilization (IVF).
And given the average age for menopause is 51, older mothers typically use donor eggs of younger women in order to conceive.
Nielsen came to fame in the early 1980s as a fashion model who posed for such photographers as Helmut Newton. She also posed for Playboy magazine.
Her profile skyrocketed when she wed Stallone in 1985 and then went on to appear with him in Rocky IV and Cobra.
They divorced in 1987, the same year she starred in Beverly Hills Cop II opposite Eddie Murphy.
Her next few films - 976-Evil II (1992), The Double 0 Kid (1992), Chained Heat II (1993), Galaxis (1995), and Snowboard Academy (1996) - didn't pack as much punch.
But then a decade later she found fame again with reality TV.
Nielsen was a hit on 2004's The Mole which led to the third season of the VH1 reality show The Surreal Life.
Next came a romance with Flavor Flav and a stint on his show Flavor Of Love before starring on Britain's Celebrity Big Brother with her former mother-in-law Jackie Stallone.
She earned a following from VH1's The Surreal Life: Fame Games then Celebrity Rehab with Dr Drew.
In 2008 she had plastic surgery for Celebrity Makeover: Brigitte Nielsen before appearing on Let's Dance, the German version of Dancing with the Stars, in 2010.