Weinstein, 74, has myriad health problems, including cancer and a history of heart trouble, and he uses a wheelchair.
He has been behind bars since 2020 and told a court in January that his health is deteriorating in New York's infamously troubled Rikers Island jail.
The ex-producer wasn't in the courtroom, but rather was waiting elsewhere in the courthouse when defence lawyer Marc Agnifilo said about 3pm on Wednesday, US time, that court officers had told him Weinstein was having chest pains.
Jurors weren't in the room at the time. They were about four hours into their closed-door discussions, and had just sent a note asking to rehear part of accuser Jessica Mann's testimony - a brief portion in which she said she was "spacing out" during cross-examination - and to review a lengthy prosecution timeline of emails and other evidence.
Judge Curtis Farber ultimately told jurors there were "unforeseen reasons" for sending them home a bit earlier than planned.
Prosecutors and Weinstein's lawyers had left the courtroom so jurors would be less likely to speculate about Weinstein's absence.
"He wants to be here, but he's having chest pains," Agnifilo told the judge before ducking out of the courtroom.
Jurors are due to get the requested information and resume deliberations on Thursday.
Weinstein has had health problems at court before. When he was sent to jail for the first time in 2020, he was taken from the courthouse in an ambulance to be checked out at a hospital for heart palpitations and high blood pressure.
In 2024, he was rushed from Rikers to a hospital and had emergency surgery to remove fluid on his heart and lungs.
Mann, 40, has testified she and Weinstein had a consensual relationship, but he subjected her to unwanted sex in a Manhattan hotel room in March 2013 after she repeatedly said no.
Lawyers for Weinstein have maintained the encounter was consensual, and have emphasised that Mann continued seeing Weinstein afterward and expressing warmth toward him.
Mann has said she was mired in complicated feelings about him, herself and what had happened, and was "normalising everything".
Her viewpoint changed in 2017, when a series of sexual misconduct allegations against the Oscar-winning Weinstein propelled the #MeToo campaign to hold people - especially powerful men - accountable for sexual misbehaviour.
Weinstein has said he "acted wrongly" but never assaulted anyone.
An appeals court overturned his 2020 New York conviction on charges that involved Mann and another accuser.
At a retrial in 2025, jurors failed to reach a verdict on Mann's portion of the case, leading to a second retrial in 2026. He is charged with one count of rape in the third degree.
