The parents of a brain-damaged invalid raped in a convalescent home five months ago prepared yesterday to move their daughter to a hospital in hopes that a doctor there would perform an abortion, their attorney said.

Helen and Tom Stegmoyer, the mother and stepfather of Laura Eldridge, 35, have been searching for a doctor to perform the risky operation since a judge granted them guardianship over their daughter and authorized an abortion.

Eldridge had been scheduled to undergo the procedure Friday night, but the doctor appointed to perform the operation failed to show up, apparently because he feared possible liability charges.

Attorney Dick Runels said Eldridge, who lies in a fetal position and cannot communicate, is to be admitted today to the University of California, Irvine, Medical Center for the "limited purpose of investigation, examination and determination as to the possibility of terminating the pregnancy, with no guarantees given in advance."

The Stegmoyers have said Eldridge, who suffers from Huntington's chorea, a rare nervous disorder, was raped while restrained in her bed at Mirada Hills Convalescent Center. Stunned doctors discovered last week while inserting a feeding tube into Eldridge's stomach that the woman was 20 weeks pregnant.