There is no need for women who have suffered a miscarriage to wait a few months before trying again, doctors said yesterday. Those who conceive again within six months of a miscarriage have the best chances of having a healthy pregnancy with the lowest complication rates. They are also far less likely to go on and have another miscarriage, a study has found.

Many NHS doctors advise women to wait at least three months, with the World Health Organisation saying they should wait six months before trying for another baby.

The latest study is especially important for women over the age of 35 because they are more likely to have trouble conceiving and have a higher risk of birth defects, according to the study, published online in the British Medical Journal.

A team led by experts at the University of Aberdeen analysed data for almost 31,000 women who had suffered a miscarriage and become pregnant again. Compared with those who had a six- to 12-month interval before conceiving again after a miscarriage, those who conceived within six months were 44 per cent less likely to have another miscarriage. They were also 52 per cent less likely to have an ectopic pregnancy or to have a termination. Furthermore, women who conceived within six months were 10 per cent less likely to need a Caesarean or to have a premature baby, and 16 per cent less likely to have a low birthweight baby. They were 8 per cent more likely to be induced.

Women with an interval of more than two years were almost twice as likely to have an ectopic second pregnancy and more than twice as likely to have a termination.

The authors concluded: "Women who conceive within six months of an initial miscarriage have the best reproductive outcomes and lowest complication rates in a subsequent pregnancy."

The researchers added: "This length of delay poses a particular problem for women in the Western world as they tend to delay childbearing for several social and economic reasons."

Dr Tony Falconer, president-elect of the Royal College of Obstetricians and Gynaecologists, said: "This paper suggests it is appropriate to conceive within six months of a miscarriage, which is at variant to WHO advice. If you wish to be pregnant, trying again soon, whenever you feel physically and emotionally ready, does not increase your risk of miscarrying next time."