A new study, published in the journal BMJ Open, suggests that high caffeine intake during pregnancy may be linked to childhood weight gain. Caffeine intake during pregnancy was associated with increased growth during the infant’s first year of life and an increased risk of the child being overweight at 8 years old. These are important findings to consider since being overweight in childhood puts people at risk of having obesity later in life.
The study looked at over 50,000 women in Norway, who took part in the Norwegian Mother and Child Cohort study from 2002 – 2008. The women’s caffeine intake was self-reported once during the 2nd trimester of pregnancy and the children’s growth was tracked from 6 weeks to 8 years old. Caffeine intake was characterized as low (0-49 milligrams/day), average (50 – 199 milligrams/day), high (200 – 299 milligrams/day), or very high (300 or more milligrams/day).
For reference, a typical 8-ounce cup of brewed coffee has approximately 130 mg of caffeine and an 8-ounce cup of tea or 12-ounce soda has approximately 50 mg of caffeine. Exact amounts vary based on the specific beverages and foods though.
The study found that women who consumed 300 or more milligrams of caffeine per day had a 66% increased risk of having a child with excess growth during the 1st year of life compared to women with low caffeine intake. In addition, the study found that women who consumed average, high, or very high levels of caffeine were more likely to have children that were overweight at 3 years and 5 years of age. By 8 years old, only the children who were exposed to very high levels of caffeine were still found to be at increased risk of being overweight though.
The findings of this study contraindicate the current recommendation from American College of Obstetricians and Gynecologists (ACOG) regarding caffeine intake in pregnancy. In 2010, ACOG reported that consuming less than 200 milligrams of caffeine per day was not associated with adverse health effects, so most obstetricians will tell patients that drinking 1-2 cups of coffee in pregnancy is considered safe.
Based on this new study, we may want to re-think our recommendations. Until additional studies are done, I would recommend consuming as little caffeine as possible and if you do need caffeine in your life, it’s still best to stay under 200 milligrams per day. Also, if you’re not yet pregnant, but are trying to conceive, this is a good time to start tapering down your caffeine intake. Decrease in fertility rates and adverse pregnancy outcomes have been associated with caffeine intake of more than 2-3 cups of coffee per day. For more information about lifestyle choices and fertility, visit our Lifestyle and Fertility page.