Smoker's embryos took 62 hours
to reach the eight-cell stage, compared to 58 hours in non-smokers
Time-lapse photography has shown that
embryos of smoking women develop more slowly.
French academics in an IVF clinic took regular pictures of an egg from the
moment it was fertilised until it was ready to be implanted into the mother.
At all stages of development, embryos from smokers were consistently a couple
of hours behind, a study showed.
The lead researcher, from Nantes University Hospital, said: "You want a baby,
quit smoking".
Smoking is known to reduce the chances of having a child. It is why some
hospitals in the UK ask couples to give up smoking before they are given
fertility treatment.
As eggs fertilised through IVF initially develop in the laboratory before
being implanted, it gave doctors a unique opportunity to film the embryos as
they divide into more and more cells.
Slow
start
Researchers watched 868 embryos develop - 139 from smokers.
It allows scientists to watch in real time how embryos
develop without disturbing them”
End
Quote Dr Allan Pacey University of Sheffield
In the clinic the embryos of non-smokers reached the
five-cell stage after 49 hours. In the smokers it took 50 hours. The eight-cell
stage took 62 hours in smokers' embryos, while non-smokers' embryos reached that
point after 58 hours.
Senior embryologist and lead researcher, Dr Thomas Freour, told the BBC:
"Embryos from smoking women, they behave slower, there is a delay in their
development.
"On average it is about two hours, it is significant and nobody knew that
before."
This study cannot say what impact the slower development has, or if this
affected the chances of having a child.
Dr Freour speculated that "if they go slower, maybe something is starting to
go wrong and they wouldn't implant."
His advice was simple: "You should quit smoking, it couldn't be easier. What
else can I say? You want a baby, quit smoking."
Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield,
said it was an "interesting" study which pioneered the use of new
technology.
"It uses a fancy piece of equipment called an embryoscope which allows
scientists to watch in real time how embryos develop without disturbing them.
"It's early days for this machine but we need trials like this to test its
potential, we know our current methods of embryo selection are based on what
looks good down the microscope to a trained eye."
The findings were presented at the European Society for Human Reproduction
and Embryology (ESHRE) meeting in Turkey.
By James Gallagher Health and Science reporter, BBC News, Istanbul
