Baby Fae, whose real name was Stephanie Fae Beauclair, died on November 15, 1984, about three weeks after receiving a transplanted baboon heart. Her death was caused by rejection of the xenotransplant (the baboon heart), which ultimately led to heart failure and organ collapse.

Who was Baby Fae?

  • Baby Fae was an infant born with hypoplastic left heart syndrome, a severe and usually fatal congenital heart defect if untreated.
  • She was treated at Loma Linda University Medical Center in California, where doctors considered her case desperate because there were no suitable human donor hearts available at the time.

The historic transplant

  • On October 26, 1984, pediatric heart surgeon Dr. Leonard Bailey transplanted a baboon heart into Baby Fae, making her the first infant to receive a cross‑species (xenotransplant) heart.
  • The operation itself was initially a technical success: the baboon heart began beating in her chest and she survived for 21 days, longer than any previous recipient of a non‑human heart.

What exactly happened to her?

  • In the first days after surgery, Baby Fae’s condition was reported as serious but stable: she was weaned off the respirator, gained weight, fed by formula, and appeared to be growing stronger.
  • About two weeks in, test results changed and doctors recognized signs of rejection, despite treatment with immunosuppressive drugs such as cyclosporine, steroids, and additional antibody-based therapies.

Why did she die?

  • The main medical cause was rejection of the baboon heart, believed to be driven largely by a humoral (antibody‑mediated) immune response against the graft.
  • A likely contributing factor was blood-type incompatibility: Baby Fae had type O blood, while the baboon donor heart was type AB, which meant her immune system could form antibodies against the donor organ.

Aftermath and legacy

  • Baby Fae died on November 15, 1984, when her kidneys failed, her transplanted heart became unstable, and resuscitation attempts were unsuccessful.
  • Her case became one of the most controversial moments in medical history, raising ethical questions about consent, animal use, and experimental surgery, but it also drew global attention to infant organ donation and helped spur the development and acceptance of human infant heart transplants.

Information gathered from public forums or data available on the internet and portrayed here.