The study found a link to lower birth rates

The research was carried out on 25,371 women who attended Aberdeen Maternity Hospital between 1980 and 1997.

It found that after a surgical delivery 66.9% of women went on to have another baby compared with 73.9% who gave birth completely naturally.

The Royal College of Obstetricians and Gynaecologists has urged doctors to consider the impact of the procedure.

Rising rates of Caesareans in the UK have caused experts to recommend more action to boost the number of women giving birth naturally, with less risk of complications and a quicker recovery.

The study, published in the British Journal of Obstetrics and Gynaecology, found that the average amount of time between births was longer for those who had a Caesarean compared with other types of delivery.

CAESAREAN DELIVERY STUDY Having another baby - Caesarean birth: 66.9% Having another baby - instrumental birth: 71.6% Having another baby - spontaneous birth: 73.9% Average time before next pregnancy - Caesarean birth: 36.3 months Average time before next pregnancy - instrumental birth: 31.8 months Average time before next pregnancy - spontaneous birth: 30.4 months Risk of future ectopic pregnancy - Caesarean birth: 9.5 cases per 1,000 Risk of future ectopic pregnancy - spontaneous birth: 5.7 cases per 1,000

Caesarean mothers were also more likely to suffer other complications in future pregnancies, the 17-year study showed.

The researchers said whether the Caesarean was planned or performed as an emergency made no difference to the rate of future pregnancies.

Women who had their baby by Caesarean were also more likely to have an ectopic pregnancy - where the fertilised egg becomes implanted outside of the womb, such as in the Fallopian tube.

The researchers said further exploration was needed to help explain their findings.

'Important finding'

Lead researcher Jill Mollison said: "This study highlights an association between mode of delivery and subsequent pregnancy.

"This is an important finding against the background of rising Caesarean section rates.

"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-Simpkins, from the Royal College of Obstetricians and Gynaecologists, said: "Those involved in the delivery of obstetric care should be aware of the association and consider its implications when making a decision to perform a Caesarean section."