Ex-president George HW Bush in intensive care as wife remains in hospital
George HW Bush and his wife Barbara both remain in hospital in Houston, with the former president in intensive care as he is treated for pneumonia.
His wife is being watched after complaining of fatigue and coughing.
Mr Bush, 92, went into the intensive care unit on Wednesday and underwent a procedure "to protect and clear his airway that required sedation", said family spokesman Jim McGrath.
Mr Bush was stable and resting comfortably at Houston Methodist Hospital, Mr McGrath said.
The 41st president was placed in the ICU to address "an acute respiratory problem stemming from pneumonia," said Mr McGrath, adding that doctors were happy with how the procedure went.
Mr Bush was first admitted to the hospital on Saturday for shortness of breath.
"I don't think there's a whole lot of money to be gained betting against George Bush," Mr McGrath said. "We're just kind of in a wait-and-see mode."
Mr McGrath said Mrs Bush, who is 91, had not been feeling well for a couple of weeks and decided "to take it out of committee and have the experts check it out". He described the move as precautionary.
Doctors initially believed the former president would be released later this week following several days of treatment, but his stay has been extended, Mr McGrath said. There is no timetable for his release.
They want to see how the former first lady responds to treatment before allowing her to return home, he added.
The Bushes, who married on January 6 1945, have had the longest marriage of any presidential couple in American history. At the time of their wedding, he was a young naval aviator. She had been a student at Smith College.
After the Second World War, the pair moved to the Texas oil region to seek their fortune and raise a family. It was there that Mr Bush began his political career, representing Houston for two terms in Congress in the late 1960s and early 1970s.
Mr Bush, who served as president from 1989 to 1993, has a form of Parkinson's disease and uses a motorised scooter or a wheelchair for mobility.
He was taken to hospital in 2015 in Maine after falling at his summer home and breaking a bone in his neck. He was also in hospital in Houston the previous December for about a week for shortness of breath. He spent Christmas 2012 in intensive care for a bronchitis-related cough and other issues.
Despite his loss of mobility, Mr Bush celebrated his 90th birthday by making a tandem parachute jump in Maine. Last summer, Mr Bush led a group of 40 wounded warriors on a fishing trip at the helm of his speedboat, three days after his 92nd birthday celebration.
Mr Bush's office announced earlier this month that the couple would not attend Donald Trump's inauguration because of the former president's age and health.
"My doctor says if I sit outside in January, it likely will put me six feet under. Same for Barbara. So I guess we're stuck in Texas," Mr Bush wrote in a letter to Mr Trump.
His son George W Bush, the 43rd president, still expects to attend the inauguration and does not plan to travel to Houston, spokesman Freddy Ford said.