BEIJING, Nov. 4 (Xinhuanet) --  Pregnant women should keep consumption of coffee, tea and cola to a minimum, said a study published on Monday that sees a link between caffeine intake and low birth weight among babies.

    Researchers of Britain's Food Standards Agency (FSA) recruited 2,635 women at between eight and 12 weeks of pregnancy, asked them about their dietary habits and monitored them for caffeine in their saliva at checkups.

    Women who took between 100 and 199 milligrams of caffeine per day faced a 20 percent increased risk of having a baby with a relatively lower birth weight compared with counterparts whose intake was less than 100 mg per day. For those who had an intake of 200-299 mg per day, the risk rose to 40 percent, and for those over 300 mg per day, it was 50 percent. 

    Birth weight is a widely used benchmark of health, especially for diabetes and heart disease.

    An average cup of coffee contains about 100 mg of caffeine and tea about half this amount, although the concentration varies according to the strength of brew and the brand of the product.

    Caffeine is also present in cola, chocolate, coca and some drugs. The so-called CARE study, published online by the British Medical Journal, said "sensible advice" would be for women to reduce caffeine intake before conception and throughout pregnancy.

    "This new advice doesn't mean that pregnant women have to cut out caffeine completely, simply that they should be careful and make sure they don't have too much. We would emphasize that the risks are likely to be very small," said the FSA's chief scientist Andrew Wadge.

    (Agencies)