Pregnant women are free to consume moderate amounts of caffeine without worrying about affecting their child's IQ, according to a new study.
The study comes from researchers at Nationwide Children's Hospital in Columbus, OH, and is published in the American Journal of Epidemiology.
Pregnant women are typically advised to consume no more than 200 mg of caffeine per day, as caffeine crosses the placenta. Although pregnant women's bodies can handle higher amounts of caffeine, the baby's metabolism is still maturing and, therefore, cannot fully metabolize caffeine.
Furthermore, caffeine increases the mother's blood pressure and heart rate, which is not recommended during pregnancy.
The usual suspects containing caffeine are beverages such as teas and coffees, but chocolate, soda and some over-the-counter headache medications also include the substance.
To further investigate how caffeine consumption during pregnancy might interfere with child cognition or behavior later on, the researchers, led by Dr. Mark A. Klebanoff from Nationwide Children's Hospital, analyzed a marker of caffeine in the blood of 2,197 expectant mothers.
The women were all part of the Collaborative Perinatal Project, which was conducted at multiple locations in the US between 1959-74 - a time when the researchers say coffee consumption during pregnancy was higher than today, given that there was little concern regarding caffeine safety.
Study is first to examine in utero caffeine exposure and child IQ
Because the study took place during a time of higher maternal caffeine intake, the researchers say they were able to assess a broader range of caffeine intakes than they would in pregnant women today.
The chemical that the researchers investigated was paraxanthine, which is caffeine's main metabolite. They looked at this chemical at two points in pregnancy and compared the levels with the child's intelligence (IQ) and behavior at 4 and 7 years of age.
"We did not find evidence of an adverse association of maternal pregnancy caffeine consumption with child cognition or behavior at 4 or 7 years of age," says Dr. Klebanoff, who adds that their study is one of the first to focus on how exposure to caffeine in utero affects a child's IQ and behavior.
He and his colleagues previously conducted a study - involving the same group of women - that found increased caffeine consumption during pregnancy did not increase the child's risk of obesity.
Although 11% of the children in the study were obese at 4 years, and 7% were obese at 7 years, the researchers said they did not find any links between the mother's caffeine intake and these cases of obesity.
Commenting on their findings, study coauthor Sarah Keim, PhD, says:
"Taken as a whole, we consider our results to be reassuring for pregnant women who consume moderate amounts of caffeine or the equivalent to one or two cups of coffee per day."
To get an idea of what 200 mg of caffeine looks like, one 8 oz cup of coffee contains about 95 mg, while one cup of black tea contains nearly 50 mg. Green tea, meanwhile, contains between 24-45 mg.
Caffeine intake through chocolate, however, can surprisingly add up; in 100 g of dark chocolate, there is approximately 45 mg of caffeine.
Medical News Today recently investigated how caffeine affects our health.