Molly Sims has given birth to her third child.

Molly Sims and baby Grey (c) Twitter

Molly Sims and baby Grey (c) Twitter

The 43-year-old model and her husband Scott Stuber welcomed a baby boy called Grey Douglas into the world on Tuesday (10.01.17).

Captioning a picture of herself with her newborn son, Molly wrote: "Welcome to the world Grey Douglas Stuber 1.10.17 .... Words do not express how grateful and happy we are to have another piece of magic! (sic)"

Meanwhile, Molly - who also has Brooks, four, and Scarlett, 21 months, with Scott - previously opened up about how her third pregnancy has been "really, really stressful".

She explained: "Being 43 ... we wanted to tell everyone, but we were super nervous about, you know, the testing ... so it's just been really, really stressful, but everything so far is on track ...

"I've been crazy sick. I wake up in the morning, I feel like I wanna vomit. I have lunch and wanna vomit, and wanna vomit at dinner ... and then when I go to bed, I still want to vomit. I have vomited at grocery stores, I have vomited in my house, I have gagged on my toothpaste."

But Molly managed to settle her cravings by having a hot chocolate "every single night".

She added: "With Brooks, I literally ate, like, seven apples a day. With Scarlett, I ate, like, seven oranges a day. And with this one ... it's crazy, but it's chocolate.

"My girlfriends last night were here visiting me, and they were like, 'Are you drinking hot chocolate?' Oh, I was -- with the little mini marshmallows that are really not good for you. I have one every single night.

"It's much more tiring [this time around]. I don't get anything done. I think I'm much more hormonal. I'm like the crazy bitch sometimes - I'll be really nice one time, and really crazy the next. My husband loves me right now. He really loves me."