The defense had been due to begin its case on Monday.
The trial is now scheduled to resume Tuesday if defense lawyer Jack McMahon is back to work.
The 72-year-old Gosnell is charged with killing a patient and seven babies.
The prosecution had been presenting its case for the past five weeks.
Former clinic workers have testified that Gosnell taught them to snip the spines of aborted babies to make sure they had died.
The defense denies that any babies were born alive. And lawyer Jack McMahon has suggested the 41-year-old woman died of unforeseen complications.
It's not clear if Gosnell will testify before the jury gets the case.
Eight clinic employees have pleaded guilty, some to third-degree murder.
The only co-defendant, unlicensed doctor Eileen O'Neill, is charged with racketeering and working without a license. Her lawyer says she worked under Gosnell's supervision.