Patrick Kielty and wife Cat Deeley are celebrating the birth of their first child, describing themselves as "beyond delighted".

So You Think You Can Dance host Deeley announced on Twitter that the couple's son was born last week.

"3 really is the magic number," she wrote.

Deeley, 39, married 44-year-old broadcaster and comedian Kielty in September 2012. They announced they were expecting their first child last September.

In a recent interview with Closer magazine, Deeley said they intend to bring their newborn home to see his family in Co Down and Birmingham as often as possible.

"For now, we're happy here in LA and are excited to bring up our child with an outdoors lifestyle," she said.

"They're going to experience the LA sunshine Patrick and I never got to experience."