Technique boosts IVF chance of pregnancy
The low success rate of
in vitro fertilisation (IVF) will be substantially improved by a new technique for counting the number of chromosomes in each cell of an early embryo, British scientists will announce today at a scientific conference.
The low success rate of in vitro fertilisation (IVF) will be substantially improved by a new technique for counting the number of chromosomes in each cell of an early embryo, British scientists will announce today at a scientific conference.
By ensuring that test-tube embryos have the correct number of chromosomes before implanting them into the womb, scientists hope to rectify the position in which even the best IVF treatment can still result in an abysmally low number of viable pregnancies.
Dagen Wells and Joy Delhanty of University College London Medical School developed the chromosome-counting technique to enable doctors to assess how many abnormal cells there are when an early embryo is at the 6-8 cell stage.
"We hope that the new technique will help embryologists to decide which embryos are the most likely to implant and develop normally. By preferentially transferring these embryos, considerably higher success rates may ultimately be achieved," Dr Wells said.
Humans have a naturally low fecundity with only a 25 per cent chance of achieving a pregnancy in each menstrual cycle even though successful fertilisation of an egg may occur in as many as 60 per cent of cycles. The difference between conception rate and birth rate is thought to be partly due to chromosomal abnormalities in early embryos, which hinder their ability to implant themselves into the wall of the womb.
By selecting those embryos with the correct number of chromosomes in each cell, embryologists hope to boost IVF success rates. Up to now, chromosome counting has been limited, with low numbers being counted in just a small proportion of the embryonic cells.
"Having a small number of abnormal cells does not automatically mean an embryo will fail to implant or that there will be a miscarriage: however, the chances of such an embryo forming a successful pregnancy are considerably less than those of a chromosomally normal embryo," Dr Wells said.
The technique, which will be given the conference prize at the American Society for Reproductive Medicine's annual meeting in San Diego this week, has been tested on 12 human embryos donated by parents having IVF treatment. Only three of the embryos were found to be completely "normal" with 46 chromosomes in all cells. Nine contained at least one abnormal cell and three contained no normal cells at all.
The findings, published in the journal Molecular Human Reproduction, demonstrate that the proportion of human embryos resulting from IVF that are completely normal is actually quite low.
Professor Delhanty said more work was necessary before the technique could be made widely available. "We are currently working on the next step - reducing the length of the procedure so that it can be applied in pre-implantation genetic diagnosis."
- 1 School playground evacuated over 'unusually aggressive' grey squirrel
- 2 Hollywood actor Mickey Rourke beats opponent 33 years his junior in exhibition boxing match
- 3 Jennifer Lawrence scores first UK top 40 single with Hunger Games track 'The Hanging Tree'
- 4 Today was a bad day for renters, landlords, and democracy
- 5 'You should come to my house and eat cheeses with me': 4-year-old sends adorable love letter to girl at school
At least 100 dead after Islamists launch attack on Nigerian mosque
Hollywood actor Mickey Rourke beats opponent 33 years his junior in exhibition boxing match
'You should come to my house and eat cheeses with me': 4-year-old sends adorable love letter to girl at school
Scientists predict green energy revolution after incredible new graphene discoveries
Russell Brand: 'Katy Perry? I don’t know who that is'
Obama: The only people with the right to object to immigration are Native Americans
Ukip says babies born to immigrants in the UK should be classed as migrants – which would include Nigel Farage’s own children
The young are the new poor: Sharp increase in number of under-25s living in poverty, while over-65s are better off than ever
David Cameron sets out immigration reforms: We should distrust Ukip and their 'snake-oil of simple solutions'
Ukip mocked after mistaking Westminster Cathedral – for a mosque
Tamir Rice: 12-year-old boy playing with fake gun dies after being shot by Ohio police
£30k - 38k per year + Benefits: Opilio Recruitment: An award-winning consume...
£40k - 45k per year + Benefits: Opilio Recruitment: A fantastic opportunity ...
£30k - 35k per year + Benefits: Opilio Recruitment: We’re currently re...
£35k - 45k per year + benefits: Opilio Recruitment: A fantastic opportunity ...