Women who stop taking the pill take longer to conceive than those using other contraceptive methods, a Yorkshire scientist has found.
More than 2,000 women took part in the study
Professor Stephen Killick from Hull Royal Infirmary led a research team
that studied 2,200 women at antenatal clinics in Sheffield and Hull.
Women using oral contraceptives took "significantly longer" to conceive than those who relied on condoms.
But Professor Killick said women should not worry about delays of weeks not months.
"It's hardly surprising when you think about it, because these women have taken contraceptive steroids to suppress their ovaries," he said.
"We've known for some time that injectible contraceptives can reduce fertility for several months after they've been used.
"We showed a similar effect from the combined oral contraceptive pill."
Professor Killick said the average time it took women who stopped using condoms to conceive was three and a half months.
For those who stopped using a combined oral contraceptive pill, it was just over five and a half months.
But 70% of the former pill users became pregnant within six months.
The research is published in the February edition of the Human Reproduction journal.