A 30-year-old woman in Aichi Prefecture gave birth to a baby in August this year after in vitro fertilization using an egg that was frozen for 12 years, according to sources. The egg was taken just before she underwent cancer treatment as a high school student.
It is rare for a woman to have a successful pregnancy in cases where an egg has been preserved for more than 10 years, an expert said.
The woman developed malignant lymphoma, a type of blood cancer, when she was a first-year high school student, said Masashige Kuwayama, head of Repro-Support Medical Research Center in Shinjuku, Tokyo, who was involved in the freezing of the woman's eggs.
As it was feared that she could become sterile due to chemotherapy, two of her eggs were extracted at Kato Ladies Clinic, a fertility treatment clinic, also in Shinjuku Ward, in 2001 when she was a second-year high school student. The eggs were then frozen and preserved.
The woman, who overcame malignant lymphoma with the chemotherapy, got married last year.
She underwent in vitro fertilization using her husband's sperm and two eggs that were thawed. One of the fertilized eggs was implanted in her womb, and she gave birth to a 3.3-kilogram boy in August.
The woman commented through a patient support group that she hopes her case will encourage other cancer patients.