Women who have had a miscarriage do not need to wait before trying to get pregnant again, say doctors.
A study by the University of Aberdeen of 30,000 women found that conceiving within six months offered the best chance for a healthy pregnancy.
The findings, published in the British Medical Journal, counter international guidelines that women should wait at least six months before trying again.
Doctors said the study would help them reassure and advise patients.
The researchers looked at data between 1981 and 2000 relating to women who had a miscarriage in their first pregnancy before going on to becoming pregnant again.
Women who conceived within six months were less likely to have another miscarriage, termination or ectopic pregnancy, the figures showed.
Also, among those who went on to give birth, conceiving within six months was associated with reduced risk of Caesarean birth, a premature delivery or a low birthweight baby compared with those women who had conceived between six months and a year.
Around one in five pregnancies ends in miscarriage before 24 weeks, a risk that increases with age.
Study leader Dr Sohinee Bhattacharya, a lecturer in obstetric epidemiology, said current World Health Organization guidelines recommend that women delay by at least six months.
The NHS Choices website advises waiting three months to give women time to come to terms with the loss and for their menstrual cycle to re-establish itself.
But Dr Bhattacharya said that for older women, who are more at risk of miscarriage, a delay may actually hamper their chances of a successful pregnancy.
"Women wanting to become pregnant soon after a miscarriage should not be discouraged.
"If you're already over 35, I would definitely advise to try again within six months as age is more of a risk than the interval between pregnancies."
The only reason women may need to delay is if they have had a complication such as infection, she advised.
It is not clear why waiting longer than six months may be associated with more risk.
One theory is that underlying fertility problems may get worse with time.
Another possibility is that women trying for another baby shortly after a miscarriage may be highly motivated to stick to a healthy lifestyle.
Dr Tony Falconer, president-elect of the Royal College of Obstetricians and Gynaecologists, said the study showed women did not have to worry about trying again once they are physically and emotionally ready.
"It may be worth taking this opportunity to talk to your GP about anything you can do to prepare for a pregnancy," he said.
Professor Steve Field, chairman of the Royal College of GPs, said: "Miscarriages are a very traumatic event for prospective mums-to-be, and this new evidence will help health professionals reassure patients and enable them to give some good news and hope to patients at a time when they are often very anxious and under great stress."
Mary Newburn, head of research and information at parenting charity NCT, said: "It will be very reassuring to many women planning a pregnancy in their 30s or 40s to know that if they miscarry they do not need to wait before conceiving again."