Kelly Osbourne reveals she is pregnant with her first baby boy

Kelly Osbourne has revealed she's expecting a baby boy.

The 37-year-old television personality has confirmed the gender of her unborn tot - whose father is Slipknot's Sid Wilson - as her music legend dad Ozzy Osbourne has struggled to keep the news that he's set to welcome a grandson a secret.

She said: "I mean, he’s told everyone … the gender of my baby before I ever got the chance to."

Her Black Sabbath rocker dad - who, with his wife Sharon Osbourne, is already a grandparent to son Jack's daughters Andy, seven, Pearl, 10, Minnie, four, and newborn Maple, born in July - has been doing a "little song and dance" about his incoming grandchild and has lots of plans for when he's here.

She told 'Entertainment Tonight': “I’m just like, ‘Aww Dad, come on.

Like, come on,’ but I will say, every single day he does this little song and this little dance about how excited he is, and he is so excited that it’s a boy. It’s the first — out of me and my brother, it’s the first boy, so, he’s like planning all these things.”

Ozzy is also grandfather to Isabelle, Kitty and Harry Hobbs, his and first wife Thelma Riley's daughter Jessica's children, and Elijah and Maia Osbourne, their son Louis' two kids.

Ozzy, 73, and Sharon, 69, have been a rock for Kelly during her pregnancy as Sid has been on tour a lot.

She added how her parents “have been incredible and been with me every step of the way on this journey, because my boyfriend is in a band, they tour, so, he’s hardly been here, so, every milestone I’ve kinda gone through with my dad, and he’s been great, even though he sometimes says the wrong thing. I’ll walk into the room and he’ll go, ‘Wow, you’re big.’ And I’m like, ‘Thanks, Dad.’”

The gender reveal comes after Kelly revealed last week she has been diagnosed with gestational diabetes.

The soon-to-be-mum has experienced the symptoms of weight gain, fatigue and ankle swelling.

She said: "First of all, gestational diabetes is not your fault.

"At first I thought it was something that I had done. I only got diagnosed with it well into my third trimester, so it wasn't like I developed it as some people get it from the get-go when they're pregnant.

"I got it in my third trimester and, basically, I thought it was something that I had done wrong."

Gestational diabetes is high blood sugar that occurs during pregnancy.

Kelly has recently cut out sugar and started watching her carbohydrate intake.

The 'One Word' singer said: "This whole pregnancy, I've had no cravings except for sugar, which is something I've never had before.

"The number one thing for me that I realised was taking me down was sugary drinks and it was juice. Because even though I was drinking fresh pressed juice, it still had a lot more sugar than I needed."

Kelly's lifestyle changes have already had a visible impact on her health.

She said: "Overall, my skin cleared up. I don't have to wear any make-up.

"My friends that haven't seen me since I started my third trimester, now that they see me, they're like, 'Whoa. What changed? Your skin is perfect,' and I know that sometimes that has to do with pregnancy, but I had pregnancy acne. I cut the sugar out and it completely went away. I think clearer."

- Bang! Showbiz