According to a new study, children born from mothers who drank around half a cup of coffee each day were shorter than their peers on average.
Researchers from the National Institute of Child Health and Human Development in Maryland in the US followed children born between 2009 and 2013 until they were eight.
And according to the results, published in Jama Network Public, after tracking the children for over eight years, researchers found a clear correlation between caffeine consumption and height.
Height difference
The difference became apparent when the child was around 20 months old and only widened as they got older.
By age seven, the difference in height between those that consumed the least caffeine and the heaviest drinkers was as large was 1.5cm on average.
By age eight, there was a 2.3cm difference.
This was all after controlling for race and maternal education, factors that could also influence a child's height early in life.
Increasing gaps
Writing in the paper, the team of researchers said: "Children of women with low measured caffeine during pregnancy were shorter than the children of women who consumed no caffeine during pregnancy, with increasing gaps in height in a historical cohort through age eight years.
"These findings suggest that small amounts of daily maternal caffeine consumption are associated with shorter stature in their offspring that persist into childhood."
Maternal caffeine consumption
It is also worth noting that no similar correlation was found when it came to body mass index, signaling that exposure to caffeine in the womb has no affect on weight during life.
But a 2020 study in the British Medical Journal found there was NO safe level of caffeine consumption for pregnant women.
The experts
The American College of Obstetricians and Gynecologists currently recommends limiting caffeine consumption to less than 200 milligrams per day while pregnant.
For context, a mug of caffeinated tea typically has about 75 milligrams of caffeine, a mug of instant coffee has about 100 milligrams and a mug of filtered coffee has about 140 milligrams.
And even chocolate has about 31 milligrams of caffeine.