Paris Hilton and husband Carter Reum have welcomed their first child together

Paris Hilton has shocked the world after revealing she and her husband, Carter Reum, are parents.

Despite not having even a hint of a baby bump, the A-lister posted to Instagram to show off her newborn bub.

An image shows her fingers carefully and beautifully wrapped around the baby's tiny hand.

She posted a blue heart emoji alongside a caption that read: "You are already loved beyond words."

Everyone has been wondering where this baby has come from and Hilton has since revealed she and Carter used a surrogate for their first baby together.

She explained to People: "It's always been my dream to be a mother and I'm so happy that Carter and I found each other.

"We are so excited to start our family together and our hearts are exploding with love for our baby boy."

The couple initially went through IVF when the coronavirus pandemic kicked off.

"We started going and doing it like a few months in because the world was shut down," she said to the entertainment outlet.

"We knew we wanted to start a family, and I was like, 'This is perfect timing. Usually, I'm on a plane 250 days out of the year, and let's just get all of the eggs stocked and ready,' and we have tons of them just waiting."

However, they eventually went down the surrogate route.

Paris nor Carter have revealed the name of their newborn, so we'll have to wait in the wings until that is revealed to the world.

They got married in late 2021, and have been discussing starting a family for ages.

The two have been friends for 15 years, according to News Corp, and started dating in 2019.

"We really wanted to enjoy our first year of marriage together as a couple, you know, before bringing kids into the mix," she said to People.

"So now that we just had our year anniversary, I can't wait for 2023."

Paris has described her husband as 'kind and so loyal and sweet and funny and brilliant'.

She said Carter makes her 'feel like a princess every single day'.

People have flocked to the comments section to congratulate the couple on their new arrival.

Chrissy Teigen wrote: "a BABY!!!!! congratulations so happy for you both!!"

Kim Kardashian added: "So happy for you guys!!!"

While Heidi Klum said: "I am Sooooooo happy for you . Sending lots and lots of love."