With a success rate of just one in three, IVF (in vitro fertilisation) isn’t the infertility cure-all we’d like it to be, so any new developments that might improve women’s chances of having that longed-for baby are more than welcome.
Major fertility breakthrough
A British woman is the first in the world to become pregnant using eggs that have been rapidly screened for chromosomal abnormalities. She wishes to remain anonymous, but the CARE Fertility clinic in Nottingham, which has treated her, say she is 41, and had 13 previous attempts at IVF and three miscarriages. She is expected to give birth in the next two months.
Looking for a 'healthy' egg
It is thought that the main reason for IVF failure is chromosomal abnormalities. A healthy egg carries 46 chromosomes – 23 pairs – but before it can be fertilised it needs to ditch 23 of these, which it packages into a structure called the polar body.
The new technique, polar body array comparative genomic hybridisation (array GCH), uses laser technology to remove the polar body without disturbing the actual egg. The chromosomes from the polar body should be a replica of those left in the egg, so by analysing these, scientists can work out what is left behind in the egg, eg, a missing chromosome means any subsequent embryo will fail, while an extra chromosome could lead to a miscarriage or a pregnancy with an inherited genetic disorder.
A form of GCH has been used successfully in the USA, but in these cases the results of analysis took five days so subsequent embryos had to be frozen and implanted at a later date. With array GCH the results can be given within 24 hours, enabling the ‘good’ eggs to be fertilised and implanted within the same cycle of treatment.
Why is this a breakthrough for so many women?
Up to half the eggs of younger women, and up to 75% in women over 39 years of age, have abnormal chromosomes. “This screening method has the potential to improve birth rates, and minimise the incidence of miscarriage and birth defects caused by chromosomal irregularity,” said Simon Fishel, director of the Care Fertility Group. “Ultimately we could reach the holy grail of one cycle of IVF, one egg, one embryo and one baby.”
Fishel's clinic has agreement from the government's fertility watchdog, the Human Fertilisation and Embryology Authority, to offer the technology to any of their patients. But because the procedure is experimental, it will not yet be offered on the NHS. The screening process costs £1,950 on top of standard IVF treatment, which can cost £3,500.
As with all such new developments, it could be many years before its true efficacy is evaluated and we know for certain that is the great leap forward, but as Stuart Lavery, a senior consultant gynaecologist at Hammersmith Hospital in London, said: “Although it is still at a very early stage, this technique may offer a new diagnostic and therapeutic hope to couples who suffer from repeated implantation failure in IVF.”