England centre Will Greenwood will arrive back in Britain on Monday after returning on a week's compassionate leave from the World Cup.
Greenwood, who scored the only try in Saturday's 25-6 win over South Africa, flew home to be with his pregnant wife who is is hospital after experiencing complications.
Last September the couple lost their first son Freddie, who lived for only an hour after being born prematurely.
Greenwood is likely to rejoin the England squad in Brisbane ahead of the final group game against Uruguay on 2 November.
"Will is flying home for a week in order that he can be with his wife Caro, who is experiencing difficulties during her second pregnancy," said England coach Clive Woodward.
"On behalf of the squad we would appreciate it if Will and Caro could be given complete privacy during this time.
"I will not be flying out a direct replacement for Will or bringing out anyone on standby as we have sufficient cover in the squad.
"Will is expected to return on Saturday 25 October in time to prepare for the Uruguay fixture."
The Harlequins star will consequently not be available for next Sunday's Pool C clash against Samoa in Melbourne.
Woodward revealed Greenwood had kept the news from his team-mates all week as they focused on the South Africa match.
"I have to pay great tribute to Will," said Woodward. "I have known about this all week and my wife Jayne went to visit Caro earlier this week.
"They tragically lost their first baby after 21 weeks of the pregnancy and obviously there are a few problems with this second pregnancy. "(Caro) is in hospital and will be in hospital for the next month or the remainder of the pregnancy.
"It has been a tough week for Will and he has handled it brilliantly and I have to say that Caro has been fantastic too.
"She wanted him to stay (in Australia) but it is critical now that we get him back on a plane so he can be with her. And all our wishes are with both of them and I hope that it all goes well."
Woodward added: "Will wanted to keep it quiet this week and not worry the players.
"He's been outstanding and considering what happened to his first child it's unbelievable.
"I've been speaking to him daily, hourly almost, and he wanted to play."