The mother of Baby Fae, the infant who survived longer than any previous human recipient of an animal heart, 21 days, has told People magazine that it took five days for doctors at Loma Linda University Medical Center to tell her about a surgical procedure used to help babies with similar heart defects.

A medical center spokesman today contradicted the mother, saying she was told of the procedure immediately but may have forgotten.

The procedure has given at least a temporary respite to up to 40 percent of babies with hypoplastic left-heart syndrome but requires surgery soon after birth.

In a lengthy interview with People, the mother said an unidentified doctor who examined the baby the day she was born, Oct. 14, told her the next day that nothing could be done to save the baby. According to the mother, identified only as Teresa, she did not hear of the operation, called the Norwood procedure, until Oct. 19, when it was described to her by Dr. Leonard L. Bailey, who later tried to save the baby by replacing her heart with that of a 7-month-old baboon. Baby Fae died Nov. 15.

Dick Schaefer, a spokesman for the medical center, said today that the infant's mother was told about the Norwood procedure on Oct. 15 but that doctors at Loma Linda "have not been recommending it. They don't consider it to be real promising."

The mother said she initially was told that "there was nothing they could do for her [Baby Fae] . . . . 'Are you sure?' I asked him. 'There's nothing that can be done, with all the new medical technology?' He said no. He said I could leave her there until she died or take her home with me."