May Make Conceiving
Again More Difficult
VIENNA (Reuters Health) - Women who give birth by caesarean section
take longer on average to become pregnant again, according to
the results of a large British study released on Tuesday.
After analysing data from more than 14,500 women, Dr. Deirdre Murphy
from the University of Bristol and others found that about one in
eight women who have a C-section take more than a year to become
pregnant again, compared with 1 in 12 of those who deliver vaginally.
The study accounted for other factors that might have reduced
fertility, including the ages of both mother and father, how long
they had lived together, whether oral contraceptives had previously
been used, smoking and drinking and ethnic background.
It also eliminated women who decided not to have another child
after caesarean, by only looking at women who actually did become
The increased difficulty in conceiving remained significant
after taking these factors into consideration, the researchers
report in the July issue of Human Reproduction. The results were
announced here at the annual meeting of the European Society of
Human Reproduction & Embryology.
"For women who've had a normal delivery, the chances of taking
more than a year to get pregnant is about 7% and for those who've
had a caesarean it is about 12%," Murphy told Reuters Health.
"That may not sound huge but it's a 50% increase, which is quite
a large number of additional women."
The number of C-sections performed in the UK has increased threefold
over the last 25 years, Murphy said. One in five babies are now
delivered by C-section in Britain.
But research into the effects of caesareans on fertility is
scarce, depriving women of evidence needed to make informed decisions
about their mode of delivery, Murphy noted. Other studies have
shown that C-sections are associated with increased risk of miscarriage,
ectopic pregnancy and an abnormally sited placenta, she added.
"I think it makes logical sense that these difficulties might
well explain why these women take longer in getting pregnant,"
The findings of this study are particularly relevant for older
women who want more than one child with a close interval between
them, the researcher explained.
"That may not be possible, and they may find themselves taking
far longer to get pregnant than they'd anticipated," she said.
Professor James Walker of the Royal College of Obstetricians
and Gynaecologists said: "This is not the first study to indicate
that caesarean section may affect a woman's subsequent ability
"For some women, a caesarean is a necessity to deliver the baby
safely. On other occasions the decision may not be as clear cut.
We need more research into the long-term effects of all methods
of delivery, so that doctors and midwives are better equipped
to help women make informed decisions."
SOURCE: Human Reproduction 2002;17.
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