Prior was preparing for his 15th Test cap when the news arrived
England wicketkeeper Matt Prior will miss the fourth Test against West Indies after flying home to be with his wife, who gave birth on Sunday.
Prior received the news at 0430 GMT that wife Emily had the couple's first child, a boy.
Prior had said he would fly home if the baby arrived early and was due to leave the tour temporarily on 2 March.
Tim Ambrose will wear the gloves in Barbados, where the penultimate Test gets under way at 1400 GMT on Thursday.
Ambrose, 26, has played 10 Tests for England, scoring 55 on his debut against New Zealand in Hamilton and then 102 against the Kiwis in Wellington.
The Warwickshire wicketkeeper was dropped for the winter tour to India after a disappointing series against South Africa at home.
But he made an impressive 74 and took two catches on day one of England's two-day match against a Barbados Cricket Association President's XI.
Prior, who made an unbeaten 126 on his debut against West Indies at Lord's in 2007, has looked assured on this tour and should regain his place for the fifth Test in Trinidad, which starts on 6 March.
The 26-year-old's absence at the Kensington Oval will mean a second alteration for England following the news that Andrew Flintoff is to miss out with a hip injury.
Prior would have been a viable option to bat at number six given his average is in excess of 40, enabling England to retain a five-man bowling attack.
But the selectors are less likely to consider Ambrose for that position, meaning they might be forced into playing four bowlers.
Ravi Bopara, who hit a hundred in the tour match on Sunday, and Ian Bell would be vying for the spare batting berth.
Worcestershire wicketkeeper Stephen Davies is part of the one-day squad but he is not scheduled to arrive in the Caribbean until later this week.
England are bidding to square the series at 1-1 following their defeat in Jamaica and draw in Antigua.