Black and white image of pregnant person drinking coffeeShare on Pinterest
Experts say that some caffeine during pregnancy can be safe, but a recent study says that it may affect a child’s height by nearly an inch. Irina Efremova/Stocksy
  • Caffeine consumption during pregnancy is an area of ongoing research, but experts continue to say that some caffeine during pregnancy may be safe.
  • Data from a recent study found that pregnant people who consumed caffeine had children who were shorter than children conceived by those who did not have caffeine during pregnancy.
  • Pregnant people can follow the advice of medical professionals and work closely with their doctors throughout pregnancy, including asking about the safety of caffeine intake.

Recommendations and tips for a healthy pregnancy have changed throughout the years with the emergence of more data.

One area of interest is how caffeine intake can impact pregnancy outcomes and child development.

A​ recent study published in JAMA found that caffeine consumption during pregnancy may impact child growth.

The study found that pregnant people who consumed caffeine had children who were shorter in stature in early childhood.

The data on caffeine intake during pregnancy is mixed.

Some evidence suggests that caffeine may be harmful to certain aspects of pregnancy. However, some caffeine intake may be fine and not cause adverse health impacts.

In fact, the American College of Obstetricians and Gynecologists states that less than 200 milligrams of caffeine during pregnancy is considered safe.

Dr. Monte Swarup, a board certified OB-GYN and founder of the nutrition supplement company HPD Rx, not involved in the study, told Medical News Today:

“Current recommendations for intake of caffeine are based on research which suggests less than 200 mg or the equivalent of one 12-ounce cup of coffee per day. It’s important to note caffeine consumption can contribute to light-headedness, nausea, and interrupt sleep.”

Dr. Julia Arnold VanRooyen, a board certified gynecological surgeon, noted that pregnant people should generally limit their caffeine consumption to less than 200mg [per] day.

“Women should always discuss any questions and concerns they have with their doctor; their physician can inform them of existing general guidelines and make any specific recommendations for a given patient, based on their unique history,” she told MNT.

The new study looked at caffeine intake during pregnancy and its impact on child growth.

Researchers examined a historical cohort of mothers between 1959–1965 and children between 1960–1974. They then examined a more recent cohort of mothers and children between 2009–2013 and 2017–2019.

Researchers measured concentrations of caffeine and paraxanthine — a metabolite of caffeine — in the pregnant person’s blood during the first trimester of pregnancy. They then looked at children’s heights up to age 8.

The analysis indicated that caffeine consumption during pregnancy was associated with children being shorter later in life.

The difference was distinct, amounting to about a 2-centimeter height difference between children whose mothers had caffeine and children whose mothers did not.

Study author Jessica Gleason, Ph.D., MPH, explained key points of the research to MNT:

“The main takeaway is that even low exposure to caffeine during pregnancy was associated with shorter height in childhood. There have only been a handful of studies that are similar to ours, and none had really evaluated height separately from overall BMI. Considering prior research, I was a little surprised that we found no association between caffeine exposure during pregnancy and child weight but found such a consistent association between caffeine and child height even up until age 8.”

The full impact of the study’s recorded height differences on children’s overall health remains unclear.

“There are strong implications demonstrating maternal consumption of caffeine of even less than 200 mg per day is associated with smaller child growth,” Dr. Swarup said.

“This is beginning at age 4 and persists to age 8. The implications of the difference in height need further research.”

Dr. Gleason added that shorter height could lead to further health problems if they persist into adulthood.

“The clinical implications of this work are unclear because the height differences we observed are so small,” she said.

“It would be important to determine whether height differences persist beyond childhood, as shorter height in adulthood has been associated with a higher risk of diabetes and cardiovascular disease.”

Overall, the study’s results indicate that caffeine during pregnancy may influence children’s height — but the study had several limitations that need to be considered.

First, there is a risk of confounding factors that researchers did not consider, such as other aspects of maternal diet.

“While providing many insights, there needs to be more information and research around the diet of the mother, paternal height, and other confounding factors,” Dr. Swarup noted.

In addition, since some of the data is from the historical pregnancy cohort, researchers cannot fully account for historical and societal factors that may have impacted pregnancy.

The study also had limited data collection in some areas. For example, in the modern-day cohort, children’s height measurements were only taken at one point in time.

Dr. Gleason noted that looking at longer-term follow-up would be a helpful component of further research.

“It would be important to explore this association between maternal caffeine consumption and child growth in later childhood to see if kids eventually ‘catch up’ in height—ideally, following the children into their early 20s after growth has stabilized. Until we have this long-term follow-up data, we cannot determine the clinical implications of shorter height measures.”

– Jessica Gleason , Ph.D., MPH, study author

While waiting for long-term follow-up in this area, pregnant people can still take steps to ensure healthy pregnancy outcomes.

Anyone expecting a child may choose to regularly communicate with their doctors and other specialists as they decide how to handle caffeine intake during pregnancy, taking any potential risks into account.