Maternal Caffeine Consumption Linked to Low Birth Weight Babies

GOTHENBURG, SwedenWomen who consume caffeine during pregnancy may increase their risk of giving birth to low birth weight baby, according to a new study published in the British Medical Journal (BMJ). The findings also suggest caffeine consumption may prolong the length of pregnancy

The World Health Organization (WHO) currently recommends a limit of 300 mg per day during pregnancy but some countries recommend a limit of 200 mg, which can be less than a single cup of coffee from some high street cafes.

To investigate the impact of maternal caffeine during pregnancy on babies, a research team from the Norwegian Institute for Public Health used information about mothers diet and birth details collected over 10 years. After excluding women with medical and pregnancy-related conditions almost 60,000 pregnancies were included in the study. All sources of caffeine were monitored in the study, including coffee, tea, carbonated beverages, as well as food including cocoa-containing cakes, desserts and chocolate.

Although caffeine consumption is strongly correlated with smoking, which is known to increase the risk for both preterm delivery and the baby being small for gestational age at birth (SGA). In this study we found no association between either total caffeine or coffee caffeine and preterm delivery, but we did find an association between caffeine and SGA. This association remained even when we looked only at non-smoking mothers which implies that the caffeine itself is also having an effect on birth weight," the researchers said.

The researchers found caffeine from all sources reduced birth weight. For a child of expected average weight (3.6 kg) this equates to 21-28 g lost per 100 mg caffeine per day. The source of caffeine also affected pregnancy outcomes. Caffeine from all sources increased the length of the pregnancy by five hours per 100 mg caffeine per day, but caffeine intake from coffee was associated with an extra eight hours of gestational length for every 100 mg caffeine per day.

According to the researchers, the association means it is not just the caffeine in coffee that increases gestational length, but there either must be a substance in coffee responsible for the extra time or a behavior associated with coffee drinking not present in women who drink only tea.

A 2011 study published in the journal Brain Research found infants with low birth weights are more likely to struggle with obesity problems later in life. The findings suggested overeating is programmed at the level of stem cells before birth when the mother has poor or inadequate nutrition.