Dr. Ariel Revel: “We believe the embryos are inactive during cryopreservation, they have no metabolism during that time, so the years that pass have no bearing.A startling birth of two healthy babies from 12-year-old frozen embryos in Israel recently provides …
Fertility experts at Jerusalem’s Hadassah-University Hospital in Ein Kerem have produced the babies for a couple from Jerusalem who had the embryos frozen in 1990. The embryos are considered to be the world’s oldest to have been implanted successfully in a womb and proves frozen embryos can remain viable for much longer than previously believed. Until now, the longest human eggs have been frozen and then defrosted to produce an in vitro fertilization (IVF) baby was seven years.
A report in the February edition of the prestigious journal, Human Reproduction, details how Dr. Ariel Revel of the In Vitro Fertilization Unit of Hadassah’s Department of Obstetrics and Gynecology and a team of Hadassah physicians handled the embryos, the in vitro process and pregnancy. Other members of the Hadassah team included Prof. Neri Laufer, head of the Department of Obstetrics and Gynecology; Prof. Alex Simon; Prof. Abe Levin; Prof. Benjamin Reubinoff all from the IVF Unit; and Dr. Anat Safran, Director of the Hadassah’s IVF laboratory at Ein Kerem. Their report confirms the finding that the duration of the storage does not appear to adversely affect the survival of frozen embryos
“I’ve read that there are rule in England that embryos are destroyed after five years, but the family can request a short extension. In Israel, we have no such regulations – the policy is to keep them as long as the family requests, Revel told ISRAEL21c. “We believe the embryos are inactive during cryopreservation, they have no metabolism during that time, so the years that pass have no bearing. The length of time that embryos are frozen is not crucial and probably there is no more damage happening during the many years they are frozen.”
In 1990, a Jerusalem resident, aged 27, and her husband, who were experiencing unexplained infertility problems, underwent in vitro fertilization producing 12 embryos.
Four of the embryos were transferred back to her womb immediately, while the other eight were frozen within 72 hours. The woman became pregnant from three of the initial four embryos and subsequently gave birth to healthy twin girls. A few years later, she became pregnant without assistance and delivered a healthy baby girl.
Two years ago, the couple decided they would like to have more children and again turned to Hadassah. Four of the eight remaining frozen embryos were transferred back and the woman became pregnant. When the fetuses were 36 weeks old, healthy twins each weighing five pounds (2,500 grams) were born
The twins – a boy and a girl – are now nine months old and developing normally, according to Revel.
“It was a normal pregnancy. At first there were triplets, but we recommended a fetal reduction to twins at 13 weeks to increase the chances that the pregnancy would stay normal until the end,” said Revel.
As the babies were effectively the children of a 27-year-old, the tests for Down’s syndrome and other genetic disorders that are normally carried out on older mothers in Israel were not performed.
According to the London Times, the previous record for long-term embryo storage is believed to have been held by a 44-year-old Californian woman who gave birth to a boy in 1998, using an embryo that had been frozen for more than seven years.
Dr Michael Vermesh, the infertility specialist who supervised the birth of that child, told the Times: “He is now a healthy five-year-old boy who I see for checks once a year. He was subjected to more than the usual follow-ups by paediatricians because of the time lag – and all his cognitive functions are perfectly fine.”
According to Revel, medical teams may be posed with ethical questions in the future if much older women asked to be impregnated with embryos frozen decades before.
“If it’s 13 years, it could be more and maybe we could see patients coming back to us at an older age, and then it raises all sorts of ethical and social questions,” he said.
Embryos are destroyed in other countries for practical reasons such as the intense maintenance needed and storage costs, Revel said. “It’s unusual for a couple to come back after such a long time.”
But Revel said his team, and Israeli researchers in general, will continue to explore the scope of questions, limitations and possibilities of vitro fertilization.
“Israel has always been at the forefront of the whole issue of fertility treatment, because the scientific community here is dedicated to the subject,” Revel said. “Many of the breakthroughs in this field have come from Israel and at international conferences on the subject, you’ll always find Israelis in the front row.