Women who stop taking the pill to have a baby may have to wait months for their fertility to recover, scientists said yesterday.

A study has found that women who had been using oral contraceptives took longer to conceive than those who had relied on condoms.

But Professor Stephen Killick, who led the research at Hull Royal Infirmary, said women should not be unduly concerned.

His team studied 2,200 women attending antenatal clinics. A difference in ability to conceive was found when those who had been taking combined oral contraceptives were compared with those who had used condoms.

"We [knew] that injectible contraceptives can reduce fertility for several months," said Prof Killick. "We showed a similar effect from the combined oral contraceptive pill. The average time to pregnancy for women who had stopped using a condom was just over three and a half months. After they stopped using a combined oral contraceptive pill, it was just over five and a half months."

The effect was stronger in women aged over 35. They took two and a half times as long to conceive as women of the same age who had used condoms. The research is published in the February issue of Human Reproduction. Press Association