Despite previous warnings, the latest research suggests that pregnant women can maintain a moderate caffeine intake without raising the chances of low birth-weight.
Previous research from Denmark found that caffeine could increase the risk of stillbirths.
The latest research was carried out by a Swedish team from the Karolinska Institute and Uppsala University who assessed 873 women during their pregnancies between 1993 and 1998.
The researchers found that there was no association between caffeine consumption and birth weight, nor was there a link to how far the pregnancy has progressed before the baby is born. The study is published in the American Journal of Epidemiology.
Interviews were conducted to gauge caffeine exposures at 6-12 and 32-34 completed gestational weeks, and the mothers' blood was analysed for cotinine levels as an indicator of smoking.
Participants had to specify if they had had coffee, tea, cocoa, chocolate, soft drinks or caffeine-containing medication. Each of these had an estimated caffeine level, for example 150ml of brewed coffee was considered equal to 90mg of caffeine, and 150ml of a soft-cola drink to 15mg.
Caffeine intake was classed as under 100mcg per day, 100 to 299mg, 300 to 499mg and 500mg plus.
The report concluded: " There were no associations between caffeine consumption and birth weight, gestational age, and birth weight ratio, neither when caffeine exposure was averaged from conception to the 32nd to 34th gestational weeks, nor when caffeine exposure was stratified by trimesters of pregnancy."
The scientists concluded : "These results do not support an association between moderate caffeine consumption and reduced birth weight, gestational age, or foetal growth."