LOS ANGELES – After a miscarriage, the time a woman should wait before trying for another pregnancy is controversial. Some practitioners believe that there should be no wait time; the World Health Organization encourages women to wait at least six months.

A study published online Thursday in the British Medical Journal reports that women who conceive within six months of their miscarriage have the best chance of having a healthy, successful pregnancy.

The study looked at data for more than 30,000 women who attended Scottish hospitals between 1981 and 2000. All of the women had had a miscarriage in their first pregnancy before getting pregnant again. The women were divided into five categories based on the interval between the miscarriage and subsequent pregnancy: less than six months, 6-12 months, 12-18 months, 18-24 months, and more than 24 months.

The scientists found that women who conceived again within six months were less likely to have a Caesarean section, preterm delivery (defined as birth before 36 weeks) or an infant of low birth weight (less than 5.5 lbs), compared with women in the other categories.

They were 66 percent less likely to have a miscarriage than women who waited six to 12 months to conceive, 48 percent less likely to have an ectopic pregnancy (in which the pregnancy occurs outside of the womb), 43 percent less likely to terminate their pregnancy and 70 percent less likely to have a stillbirth.