Regular consumption of low levels of caffeine during pregnancy has been linked to slightly shorter children. This is based on a new study from the National Institutes of Health (NIH) that evaluated data from two prior studies.

The study found that children of women with low caffeine intake (including below the current recommendation of 200 milligrams [mg] per day) during pregnancy were slightly shorter than children born to women who consumed no caffeine while pregnant. The gaps in height widened to 2 centimeters (cm) between ages 4 and 8 years old.

The researchers believe that caffeine may restrict the flow of blood to the placenta, which can reduce fetal growth. They also noted that caffeine can cross the placenta and enter the fetal bloodstream, which could directly affect fetal growth.

It is important to note that the study did not find a causal relationship between caffeine consumption and shorter children. More research is needed to confirm the findings and to determine the exact mechanisms by which caffeine may affect fetal growth.

However, the study does suggest that pregnant women may want to limit their caffeine intake, even if it is below the current recommendation. The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women consume less than 200 mg of caffeine per day. This is about the amount of caffeine in a cup of coffee or tea.

If you are pregnant and concerned about your caffeine intake, talk to your doctor. They can help you develop a plan to reduce your intake safely.