Earlier this week, a source spotted Kayte, 35, at LAX airport in Los Angeles sporting a large baby bump. By the looks of it, she could potentially be around six months along.
For Kelsey, 61, this will be his third child with his wife, and his seventh child overall! The pair married in 2011, and are parents to four-year-old Faith Evangeline Elisa and two-year-old Kelsey Gabriel Elias.
The Cheers and Frasier star also has four children from his previous marriages, three daughters and a son: Spencer, 32, Greer, 24, Mason, 14, and Jude, 12.
Spencer is a successful actress, appearing in TV shows such as Greek. Her younger sister, Greer, has followed the family occupation of acting, starring in the teen MTV series Awkward and is also a beauty pageant star.
Spencer and Greer Grammer
Sadly, starting a family hasn't always been the most straightforward path for Kelsey and Kayte. Just two months after their announcement that they were expecting a child in 2010, Kayte sadly suffered a miscarriage.
Two years later, Kayte was pregnant with twins, but the couple's son did not survive his birth.
'A glorious birth with a lingering sadness is ours today. We choose to celebrate the life that has been given to us,' said the couple in a statement during which they announced the birth of Faith, his twin sister.
Kayte and her daughter Faith in 2013
Kayte, a fellow Brit, was previously a flight attendant, and began dating Kelsey in 2010. The pair announced their engagement in December of that year, and were married at the Plaza Hotel in New York City in 2011 - two weeks after Kelsey's divorce from former Playboy model Camille Donatacci.
We wish the couple a wonderful and joyful pregnancy!