Europe South Asia Asia Pacific Americas Middle East Africa BBC Homepage World Service Education

Front Page



UK Politics







Talking Point

In Depth

On Air

Low Graphics

Monday, June 28, 1999 Published at 11:00 GMT 12:00 UK


Older women's pregnancy chances boosted

Sceintists can analyse cells from an embryo

Older women undergoing IVF or other assisted conception techniques could now have the same chance of achieving a successful pregnancy as younger women thanks to a technique developed by scientists.

Researchers have perfected a way to allow doctors to screen a single cell from an embryo before the embryo is transferred to the woman's uterus.

As women get older the risk of an embryo containing the wrong number of chromosomes in its cells increases by up to 70-fold. This condition is called aneuploidy.

Chromosomes contain the genetic information, and aneuploid embryos are more likely to fail to implant in the womb, to miscarry or to lead to severe malformations such as Down's sydrome.

Aneuploidy is one of the major reasons behind the lower success rates for assisted conception in women aged over 37.

Italian researchers have now found a way to screen out aneuploid embryos, and to achieve the same pregnancy success rate in women aged 38 to 44 as in their younger patients.

They have achieved this using a technique called FISH (fluorescence in situ hybridization) which enables the analysis of specific genetic information from a single cell.

The technique worked for IVF and for ICSI (intracytoplasmic sperm injection) in which a sperm is injected directly into an egg.

'Age no longer a handicap'

[ image: Pregnancy is more likely to fail as women get older]
Pregnancy is more likely to fail as women get older
Dr Anna Ferraretti, clinical director of the SISMER Reproductive Unit in Bologna said: "Women planning IVF or ICSI in the final part of their reproductive life can now enter treatment feeling their age is not a handicap any more.

"Pre-implantation genetic screening (PSG) is able to overcome the natural reproductive failure that occurs due to their eggs aging."

Dr Ferraretti, speaking at the European Society of Human Reproduction and Embryology annual meeting in Tours, France, on Monday, said that since September 1996, women over 37 entering SISMER's clinic for several different infertility factors were asked to undergo PGS using the FISH technique to separate embryos carrying chromosomal abnormality from those evaluated as normal.

In total 128 patients aged 38-44 who agreed to undergo PGS of all their IVF-generated embryos had the same pregnancy rate (41%) as 700 younger patients who underwent conventional IVF/ICSI treatment without PGS.

The miscarriage rate in the older women was only four per cent.

In contrast 182 patients aged over 37 who declined PGS achieved only a 25% pregnancy rate and the miscarriage rate was 15%.

The scientists warn that because the FISH technique is limited by using a single embryonic cells, there has been a 5-7% error rate up to now.

Therefore the women were also strongly recommended to undergo conventional prenatal diagnosis to avoid the possibility of an affected baby.

Professor Ian Craft, director of the London Fertility Centre, said the technique would be particularly helpful to women over the age of 40 who suffered a miscarriage rate of one in two when they were helped to conceive artifically using their own eggs.

Mr Sam Abdalla, director of the IVF unit at Lister Hospital, said: "It would be a very notable thing if this allowed us only to transfer embryos that are chromosomally competent."

Advanced options | Search tips

Back to top | BBC News Home | BBC Homepage | ©

Health Contents

Background Briefings
Medical notes

Relevant Stories

28 Jun 99 | Health
Gene test cuts out cystic fibrosis

28 Jun 99 | Health
Fertility doctors can cut twin pregnancies

27 Apr 99 | Health
Aspirin 'doubles IVF pregnancy chances'

31 Mar 99 | Medical notes
IVF: The facts

30 Mar 99 | Health
Fertility technique 'may cause genetic defects'

17 Feb 99 | Health
IVF advances on the way

Internet Links

The Infertility Center

Reproductive Health Online

London Fertility Centre

The BBC is not responsible for the content of external internet sites.

In this section

Disability in depth

Spotlight: Bristol inquiry

Antibiotics: A fading wonder

Mental health: An overview

Alternative medicine: A growth industry

The meningitis files

Long-term care: A special report

Aids up close

From cradle to grave

NHS reforms: A guide

NHS Performance 1999

From Special Report
NHS in crisis: Special report

British Medical Association conference '99

Royal College of Nursing conference '99