A review of existing data confirmed that conceptions within six months of a miscarriage were less likely to result in a repeat miscarriage or preterm birth.

Rates of pre-eclampsia, or high blood pressure in pregnancy, as well as low birth weight and stillbirths were found to be no different in conceptions within half a year and those after six months.

"Contrary to WHO guidelines, recommending at least six months' wait after a miscarriage, our meta-analysis of all published studies on this subject to date shows definitively that less than six months is best,” said Dr Sohinee Bhattacharya, of the University of Aberdeen.

“One explanation might be that if somebody has had a miscarriage they might take particularly good care of themselves, be more motivated and may be more fertile, but that is just speculation at this point.”

The Miscarriage Association welcomed the review.

Its national director Ruth Bender Atik said: “It confirms that couples can choose to try again whenever they feel ready to do so.”