Posted: 20:03, 31 October 2022 | Updated: 20:28, 31 October 2022
Drinking just half a cup of coffee a day during pregnancy can reduce a child’s height by almost a centimeter, according to an official study. Infants born to women who consumed 50mg of caffeine each day were 2cm shorter than their peers at age eight. The finding held even after adjusting for other factors that affect a child’s height — including the mother’s age, smoking status and income. Researchers say the results — based on an analysis of 2,500 boys and girls in the U.S. — show expectant mothers should avoid coffee altogether. Current US guidelines recommend that pregnant women limit their daily intake to about 200 mg. The average 8 oz cup of coffee contains about 100 mg of caffeine. Caffeine is thought to constrict blood vessels in the uterus and placenta, which could reduce blood supply to the fetus and hinder growth. The study is the first of its kind to use blood tests to measure pregnant women’s caffeine intake instead of surveys, which are less reliable. A new study finds that children born to mothers who consumed about half a cup of coffee each day were shorter than their peers on average (file photo)
The dangers of caffeine consumption during pregnancy
Doctors recommend that expectant mothers consume no more than 200 mg of caffeine per day. Studies have linked consumption of the substance during pregnancy to lower birth weight. Mothers who drink caffeine while pregnant may also increase their risk of miscarriage or premature birth. Children are also more likely to suffer from behavioral problems, as the substance can affect the brain’s neural pathways. A recent study also found that children born to mothers who used caffeine during pregnancy are shorter than their peers on average. The fetus cannot break down caffeine once it crosses the placental barrier, according to research, leading to a host of problems. The results were published in the journal Jama Network Open. Researchers from the National Institute of Child Health and Human Development in Maryland followed children born between 2009 and 2013 until they were eight years old. Mother-child pairs recruited for the study were divided into four groups based on the amount of caffeine the mother consumed during pregnancy. Plasma samples were collected from each mother during her first and third trimesters to measure how much caffeine the mother drank. Those with 25.4 nanograms per milliliter (ng/mL) or less of caffeine detected in plasma samples were placed in quartile one. Mothers in the highest quartile had levels of 575.3 ng/mL or more. The researchers note that it would only take about 50 mg of caffeine per day to get a person from the first to the fourth quartile. After following the children for more than eight years, the researchers found a clear correlation between caffeine consumption and height. The difference became apparent when the child was about 20 months old and only widened as they grew older. By the age of seven, the difference in height between those who consumed the least caffeine and those who drank the most was as great as 1.5cm on average. By age eight, there was a 2.3 difference. All of this was after controlling for race and maternal education, factors that could also affect a child’s height early in life. No similar association was found for body mass index, indicating that caffeine exposure in utero does not affect weight during life. Writing in the paper, the team said: “Children of women with low caffeine readings… during pregnancy were shorter than children of women who did not consume caffeine during pregnancy, with increasing height gaps in a historical cohort up to age eight. “These findings suggest that small amounts of daily maternal caffeine consumption are associated with shorter stature in their offspring that persist into childhood.” There is limited information about why caffeine exposure in utero and early in life may stunt growth. In a 2021 study, researchers found that caffeine causes blood vessels in the uterus and placenta to constrict, reducing blood supply to the fetus. This led to the babies having a lower birth weight, although they did not determine the long-term effects this could have on their development.
