Even small amounts of daily caffeine consumption by pregnant women -- the equivalent of about two daily cups of coffee -- may shorten their kids' height throughout early childhood, a new study suggests. Photo by stokpic/Pixabay
Oct. 31 (UPI) -- Even small amounts of daily caffeine consumption by pregnant women -- the equivalent of about two daily cups of coffee -- may lead to shorter offspring throughout early childhood, compared with the growth of children whose mothers avoided caffeine while pregnant, a new study suggests.
Higher maternal caffeine intake during pregnancy was associated with offspring's shorter stature lasting to age 8, according to the research led by the National Institute of Child Health and Human Development, a part of the National Institutes of Health.
"Though the clinical implications of an approximately 2-centimeter [roughly 8/10 inch] height difference are unclear, our findings for height are similar in magnitude to those of children whose mothers smoked during pregnancy," the researchers said in their original investigation.
However, the study found no strong associations between maternal caffeine consumption during pregnancy and children becoming overweight or obese.
The findings were published Monday in JAMA Network Open.
The researchers said that, given that roughly 8 in 10 U.S. pregnant women consume caffeine, it is important to determine whether in utero caffeine exposure has long-term growth implications in offspring.
"Caffeine has a short half-life and is primarily metabolized to paraxanthine in as little as three hours in pregnant women in their first trimester," and both caffeine and this metabolite cross the placenta, the research paper said.
Researchers looked at concentrations of caffeine and its primary metabolite, paraxanthine, from maternal plasma and serum collected in the first trimester of pregnancy.
"By using biomarker data, we overcame many ... limitations and recorded caffeine exposure from consuming certain foods, such as chocolate and decaffeinated beverages, which may contain small amounts of caffeine," the research paper said.
Next, the scientists evaluated body mass index, weight and height among the women's offspring ages 4 to 8, conducting in-person exams, analyzing two study populations involving about 800 and 1,600 children, respectively.
The researchers suggested future research in caffeine consumption during pregnancy should follow children's growth "into puberty and beyond to determine whether height gaps continue to widen into adulthood, and whether shorter height associated with maternal caffeine consumption confers greater risk for cardiometabolic dysfunction."
The study's lead author is Jessica Gleason, a perinatal epidemiologist at the National Institute of Child Health and Human Development who analyzes how various exposures during pregnancy and early life influence health trajectories over a person's lifetime.
In March 2021, Gleason led a separate study of 2,000-plus women that found higher levels of caffeine consumption were "significantly associated" with babies' lower birth weight, shorter length, and smaller head, arm and thigh circumference.
