Newshub host Samantha Hayes has announced the arrival of her baby boy, Marlow River Blaauw.

Marlow was born on September 19 but Hayes said on Instagram the news was "so good" they had to keep it to themselves for a while.

View this post on Instagram

News so good we had to keep it to ourselves for a while. Marlow River Blaauw was born at 8.38pm on 19.09.19 weighing 3.38kg (7.5 pounds). He’s a determined, snuffly, beautiful wee boy & we love him to pieces. Huge thanks to the team who got him here safely & who have looked after us since.

A post shared by Samantha Hayes (@samanthahayes) on Sep 22, 2019 at 9:09pm PDT

"News so good we had to keep it to ourselves for a while," she wrote on Instagram.

"Marlow River Blaauw was born at 8.38pm on 19.09.19 weighing 3.38kg (7.5 pounds). He's a determined, snuffly, beautiful wee boy & we love him to pieces.

"Huge thanks to the team who got him here safely & who have looked after us since."

View this post on Instagram

Tonight was my last night presenting the news for a while. I feel sad saying goodbye to my @newshubnz family, who I adore, but I’m also so excited about beginning my own little family of three. Not long now till the little one arrives!

A post shared by Samantha Hayes (@samanthahayes) on Sep 12, 2019 at 1:40am PDT

The Newshub presenter and Dancing With the Stars winner announced her pregnancy on Instagram back in May.

"Super excited to finally break the news that Jay & I are having a baby!" she wrote at the time.

"We've been keeping it under wraps but the bump has now well and truly popped. Can't wait to meet our little one in spring."