Aug 2 2005
Researchers have found, after carrying out a 17-year study following 25,370 women, that women who have their baby by caesarean section, are less likely to have another pregnancy.
They also found that the average amount of time between births was greater for those who had undergone caesareans than those who gave birth naturally.
Apparently more than one in five women in England have caesareans and the rate is rising, which has provoked concern over the risks to women and babies.
This latest study, based on the Aberdeen maternity hospital between 1980 and 1997, was unable to determine whether the women's fertility was being compromised by having a caesarean, by suffering tubal damage for instance, or whether women who had undergone the experience just did not want to do so again.
Lead researcher Jill Mollison, of Aberdeen University's medical school, however highlights the importance of the findings against the background of rising caesarean rates.
She says future studies should focus on exploring whether failure to conceive is due to voluntary or involuntary factors and compare this across different modes of delivery.
Peter Bowen-Simpson, from the Royal College of Obstetricians and Gynaecologists, says those involved in the delivery of obstetric care should be aware of the association and consider its implications when making the decision whether to perform a caesarean section.
In the study it was found that 66.9% of women who had a caesarean went on to have another pregnancy, against 71.6% who had instrumental vaginal delivery and 73.9% who had a spontaneous vaginal birth.
The average length of time between pregnancies in the three groups was 36.3 months, 31.8 months and 30.4 months.
The researchers also found that the women who had a caesarean were also more likely to have an ectopic pregnancy the next time, a dangerous complication where the fertilised egg becomes implanted outside the womb.
The study is published in the British Journal of Obstetrics and Gynaecology.