Frozen eggs aid wannabe Irish parents
A technique that flash-freezes embryos has resulted in 13 pregnancies here this year
The first Irish babies conceived from embryos flash-frozen at IVF clinics will be born at the start of next year, after their parents were treated with an improved fertility method.
The technique, which involves freezing embryos in liquid nitrogen at -196C within seconds, may eventually allow single Irish women to store their eggs until they reach their early thirties. At present, Irish women who want to preserve their eggs have to go abroad.
Using embryos thawed from flash-frozen embryos, a process known as vitrification, 13 women in Ireland are now pregnant. The couples were treated at three Irish clinics licensed for the procedure by the Irish Medicines Board earlier this year. They are the Waterstone Clinic; the Hari unit at Dublin’s Rotunda hospital; and the Merrion Fertility Centre at the National Maternity Hospital on Holles Street.
As many as 98% of vitrified embryos survive thawing, compared with 75% of those frozen using the slower method traditionally used by Irish clinics. This makes it easier to transfer them to the womb intact. The process was first successfully used in Japan in 2001, and the first baby in the UK conceived with this technique was born in 2008.
While it has been possible to freeze sperm for decades, eggs and embryos contain more fluid. With the older method of freezing there was a greater chance that ice crystals would form and reduce the likelihood of an embryo or egg surviving the thawing process. To improve conception rates, some Irish clinics had been implanting patients with two or three embryos. This can lead to pregnancies with twins or triplets, which carry greater medical risks.
Fifty-three couples had embryos flash-frozen at the Waterstone Clinic this year, according to Dr John Waterstone, its medical director. Two women subsequently became pregnant. “The numbers are small, but it’s a 100% survival rate so far from embryos vitrified and thawed, compared with 75% before”, he said.
Fertility problems affect about one in six couples, prompting up to 3,000 to turn to IVF every year. The freezing of embryos, an integral part of most fertility treatments, has prompted ethical debates over when life begins and whether unused embryos should be discarded.
Irish clinics now allow unused frozen embryos to “thaw and perish”, according to Waterstone, after the Supreme Court ruled in 2009 that they did not qualify for the constitutional protection of the unborn. The court case involved Mary Roche, a Dublin woman, who wanted three frozen embryos fathered by her estranged husband to be implanted in her womb, against his wishes.
“Some pro-lifers still get hot and bothered and equate a three-day-old embryo with human life”, Waterstone said. “But the law says that they are not protected unless they are implanted”.
The Hari Clinic has had five successful pregnancies since introducing embryo vitrification in February. Edgar Mocanu, its consultant in charge, said it is the only clinic licensed in Ireland to freeze eggs, but offers the service only to women who are about to undergo cancer treatment, which can erode fertility.
As Irish women choose to have children later in life (the average age in 2010 was 31.7 compared with 28 in 1990), demand for egg freezing has increased. “Women’s fertility does diminish after the age of 37,” said Waterstone, who has declined requests from women wanting their eggs frozen.
“Some women have babies at 45, but they are the exception. Women know when they get older, their eggs can deteriorate and they are less like to become pregnant.”