Childless couples trying to start a family using in vitro fertilization are putting mothers and babies at risk by implanting multiple embryos, experts say. Limiting the number of embryos used in IVF would reduce the number of newborn deaths, prevent cases of severe eye and brain damage and cut the time babies spend in hospital, the team from the University of Montreal have found.
It comes as the Human Fertility and Embryology Authority (HFEA) in the UK announced a drop in the number of multiple births following IVF after a drive to cut twin and triplet births. The health push saw 22 per cent of births in the first six months of 2009 being two or more babies, down from 24 per cent in 2008. The HFEA launched the initiative in January 2009 with the overall aim of cutting the IVF multiple birth rate to 10 per cent in the coming years.
The United States and Canada currently allow multiple embryos to be transferred in each IVF cycle. The Canadian report found that in 2005, 29 percent of IVF pregnancies in Canada were twins and about one percent were triplets. Without fertility treatments, the rate of twins is about one per cent, while triplets occur in just one of every 8,100 births, according to the advocacy organization Multiple Births Canada.
The study said that if IVF were limited to one embryo for each attempt to become pregnant, there would be just three pairs of twins for every 100 deliveries, and no triplets. This drop in multiple births would greatly reduce the rate of premature births and the complications that often result.
During IVF, eggs are fertilized by sperm outside the body and then transferred to the womb. Implanting more than one embryo is thought to increase a woman's chances of pregnancy, but it also increases the odds of a multiple birth. All IVF clinics must now have a strategy for reducing their number of multiple births. And researchers at the University of Montreal said Canada and the U.S. should consider following Britain's lead.
Twins and triplets, whether conceived through IVF or naturally, have a higher risk of health problems than single babies. Half of all twins are born prematurely and have a low birth weight of under 5.5lbs. And triplets have a 90 per cent chance of being born prematurely and of low birth weight, and the risk of premature babies dying in the first week is around five times higher for twins and nine times higher for triplets than single babies. Twins are also four times more likely to have cerebral palsy than single babies, while triplets have a risk that is 18 times higher.
Women who are carrying twins or triplets have higher chances of miscarriage, anaemia, haemorrhage, early labour and needing a Caesarean section. And up to a quarter of multiple pregnancies will lead to high blood pressure in pregnancy.
Around 80 per cent of IVF treatment is carried out in the private sector and the HFEA has been urging private clinics to drive down their rates. Women under 35 have a higher chance of success through IVF and therefore a higher chance of multiple pregnancy if two or more embryos are transferred.
The data from the HFEA showed that pregnancy and live birth rates from IVF have broadly been maintained despite the target to reduce multiple births. Professor Lisa Jardine, chair of the HFEA, said: 'It's excellent news that the number of multiple births is coming down whilst overall success rates for patients are still being maintained.
'This shows that the policy is proving successful.' Susan Seenan, from Infertility Network UK, said the NHS must fund three full cycles of IVF, as laid down in 2004 guidelines from the National Institute for Health and Clinical Excellence. 'With full funding on the NHS - if patients could access three cycles - a lot more women would be willing and able to go for single embryo transfer. 'This would lead to better outcomes for patients and cut the number of multiple births. Some women who are only getting one cycle feel they are limiting their chances of success. "Without full funding, patients are always going to struggle with single embryo transfer. Implementing the Nice guidelines would have a big impact.
'We are big supporters of single embryo transfer but it needs to come with full funding.' But the author of the Canadian study considers the British approach to be the way forward for the U.S. and Canada. Keith Barrington said in the Journal of Pediatrics: 'If you by chance have a premature baby and are unlucky enough to have that child suffer with complications, that's one thing. 'But to actually have a procedure that increases the chance of that happening is something that should be changed.'
The United States and Canada currently allow multiple embryos to be transferred in each IVF cycle. The Canadian report found that in 2005, 29 percent of IVF pregnancies in Canada were twins and about one percent were triplets. Without fertility treatments, the rate of twins is about one per cent, while triplets occur in just one of every 8,100 births, according to the advocacy organization Multiple Births Canada.
The study said that if IVF were limited to one embryo for each attempt to become pregnant, there would be just three pairs of twins for every 100 deliveries, and no triplets. This drop in multiple births would greatly reduce the rate of premature births and the complications that often result.
Article: 13th May 2010 www.dailymail.co.uk
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