Hilaria Baldwin has shown off her weight loss, just over four months after giving birth to her fourth child.

Hilaria Baldwin via Instagram (c)

Hilaria Baldwin via Instagram (c)

The 34-year-old fitness expert gave birth to her son Romeo - whom she has with her husband Alec Baldwin - four and a half months ago, and has taken to Instagram to document her weight loss results as she works to regain her pre-pregnancy figure.

Posting a collage of images of herself from when she was nine months pregnant, 12 days after labour, and now at four and a half months after labour, Hilaria - who also has Carmen, five, Rafael, three, and Leonardo, two, with Alec - wrote: "The recovery from baby number 4 continues....I share my journey and posts here because I believe so strongly that smart exercise, good eating, and a calm mind= healthy body. And I want you to experience it too because life is so worth living to it's max...and you are so worth it. (sic)"

Hilaria is known for keeping her body fit, and recently credited her toned physique with helping to make her labours painless.

She said: "I'm fit before pregnancy, I stay as fit as I can during pregnancy, and that I think has allowed me to have pretty great labours, deliveries and recovery. This time was hard because I had pneumonia during my labor and delivery, so I was really sick. It wasn't as fast as the other times, but I made a comeback."

The health and wellness expert feels it is important to focus on her fitness, despite her busy schedule looking after her four kids.

She added: "I have to work out when it's convenient for my four little children and my husband and my two dogs. A lot of times, what I'll do is I'll get up, get the kids ready and then I'll go for a jog. Al gets the kids in the car and will meet me at the end of my jog. And then we go and we drop the kids off at camp.

"I'm really just so efficient with trying to find windows of time. I know that my jog is 30 minutes, and if I can make my 30-minute jog and then when nap time is I can do another 30 minutes of yoga or whatever it is, that's a really good day."