Wake-up call - the cost of caffeine in pregnancy

The link between the caffeine intake of expectant mothers and low birth-weight babies is being explored in a groundbreaking study which will, for the first time, link caffeine intake with individual variations in metabolism - or breakdown - of caffeine.

Research has suggested too much caffeine during pregnancy - over five cups of ordinary strength coffee a day - could increase the risk of having a low birth-weight baby. These babies are at greater risk from a range of problems in later life, including developmental delay in childhood and high blood pressure in adulthood, making this an important relationship to understand. Many previous studies have not, however, included an accurate measure of caffeine intake or taken into account other factors, such as a person's individual metabolism of caffeine.

The CARE study is looking for the first time at the relationship between caffeine intake from a variety of sources, caffeine metabolism during pregnancy and the risk of having a low birth-weight baby. Dr Sara Kirk from the Leeds University's Nutritional Epidemiology Group explains: "Caffeine is present in many products from chocolate to over-the-counter medications such as flu remedies. It's also hard to measure a person's caffeine intake as caffeine levels in drinks vary from one cup of coffee or tea to another."

Project leader Professor Janet Cade said: "The findings of this study will be of great importance in providing advice to pregnant women, based on the best available evidence. We hope it will clarify the role of caffeine in pregnancy and inform health professionals working with pregnant women."

The study in Leeds is in collaboration with the department of Obstetrics and Gynaecology at Leeds General Infirmary, and the University of Leicester and is funded by the Food Standards Agency.