Caffeine During Pregnancy: How Much is Safe?
Consuming caffeine during pregnancy has often been debated by medical professionals concerning the risks it imposes on the developing fetus.
Caffeine is a drug and it does have real physiological effects on those that consume it and these effects are passed on to the unborn child through the placenta.
However, the question that exists is to what extent does caffeine consumed during pregnancy become harmful?
There are several hypotheses related to the possible dangers caffeine may have on the fetus. Let’s take a look at those and the research that either supports the danger or refutes it.
Caffeine During Pregnancy Causes Miscarriage
Many OBGYNs tell mothers to abstain from all caffeine during pregnancy because it increases their risk of miscarriage.
There are several studies that have shown evidence for an increased risk of miscarriage or early stillbirth delivery among pregnant women who consumed more than moderate amounts of caffeine.
- A 2002 study showed that women who drank 8 or more coffees (>800 mg) were at greater risk for early stillbirth. src.
- Another study showed that expectant mothers consuming 600 mg of caffeine or more had a greater risk of miscarriage. src.
- A California study showed that pregnant women consuming greater than 300 mg of caffeine daily had a greater risk of miscarriage during the first trimester. src.
- A 2008 study showed that those consuming 200 mg of caffeine or more daily doubled their risk of miscarriage. src.
- A 2016 study showed that both women and men who consume at least two caffeinated beverages daily in the weeks prior to conception are at greater risk for potential miscarriage. src.
Caffeine Restricts the Growth of the Fetus
There is also a belief that caffeine stunts the growth of children and unborn babies. While there isn’t evidence that it stunts the growth of children, there are some studies that support this notion for developing fetuses.
- A 2008 study showed that pregnant women who consumed 100 mg or more of caffeine had an increased risk of fetal growth restriction. src.
- 2013 research showed that women who consumed caffeine had an increased risk of delivering babies with lower birth weight. src.
- A 2018 study of over 900 Irish mothers showed an association between caffeine intake (both coffee and tea) and adverse birth outcomes such as lower birth weight and smaller head circumference. src.
Caffeine During Pregnancy Produces Hyperactive Children
Some doctors may tell expectant mothers that caffeine during pregnancy leads to ADHD or hyperactivity disorder. However, the research conducted with this hypothesis doesn’t support this belief. Children that were exposed to caffeine in the womb were at no greater risk of developing ADHD or hyperactivity than children who weren’t. src.
However, a 2021 study analyzed brain scans of 9 and 10-year-olds and found that those exposed to caffeine in utero had marked changes in brain structure. Researchers believe this could lead to behavioral difficulties later in the child’s life. src.
Caffeine Causes Early Delivery
Some people believe that mothers who drink caffeine while pregnant will increase their chances of having a preterm delivery.
- A 2012 Norwegian study showed no link between caffeine consumption and early preterm birth. src.
- A 2010 American Society for Nutrition analysis of published research found no evidence that caffeine consumption leads to preterm delivery. src.
Coffee Linked to Childhood Leukemia
They found that pregnant women who drank…
- Some coffee resulted in a 20% increased risk for their child.
- More than 2 cups of coffee (about 300 mg of caffeine) resulted in a 60% increased risk for their child.
- 4 or more cups (about 600 mg of caffeine) resulted in a 72% increased risk of leukemia.
It is believed that caffeine alters the fetal DNA making the baby more prone to developing leukemia.
Caffeine Linked to Possible Liver Disease in Offspring
This study wasn’t a human study but a study conducted on rats. However, the study showed that when pregnant rats were given moderate to large doses of caffeine, their babies were more likely to develop liver disease later in their life cycle.
More research is needed but the study’s authors think that expectant mothers should avoid caffeine while pregnant. The full study is published in the Journal of Endocrinology.
Caffeine, Pregnancy, and Childhood Obesity
Another study linked caffeine consumption by pregnant mothers with an increased risk of childhood obesity.
The 15-year-long research study published in The International Journal of Obesity found that children born to mothers who did not give up their caffeine consumption during pregnancy were 89% more likely to become obese compared with children who were not exposed to caffeine in-utero.
The results were also dose-dependent, in that the more caffeine the expectant mother consumed the greater the risk of her child becoming obese.
The researchers believe this occurs because…
Brain functions have increasingly been shown to have an important role in regulating appetite and other metabolic processes. Caffeine, a neural stimulant, can alter fetal brain development impacting normal neural transmission vital to normal brain function, thus metabolic processes.
And, another study conducted in Norway also found that pregnant women who consumed caffeine amounts greater than 50 mg per day had an association with a higher risk of having a child with excess growth and obesity during the first 8 years of their child’s life. This study is published in the British Medical Journal.
How Much Caffeine While Pregnant is Safe?
The American College of Obstetricians and Gynecologists says that 200 mg or less a day is probably safe for the developing fetus and The World Health Organization recommends that expectant mothers consume no more than 300 mg per day.
The European Food Safety Authority released its research regarding caffeine safety. They concluded that there isn’t enough evidence that 200 mg of caffeine or less poses any risk to the unborn child.
Also, research from Nationwide Children’s Hospital also found that there was no evidence that moderate caffeine consumption during pregnancy had any negative implications for the baby’s long-term cognitive and behavioral development. In the study, they analyzed the caffeine levels of blood samples taken from pregnant mothers between 1959 and 1974 and then compared the data to the children’s IQ and behavioral records.
While most of the research above does point to increased risks associated with caffeine greater than 200-300 mg, there are some studies that show some risk with even lower daily amounts of caffeine. A 2020 study showed that no amount of caffeine is safe after reviewing all the available research to date. This study was published in the British Medical Journal.
When it comes to women consuming caffeine while pregnant, it may be wise to err on the side of caution and abstain from most or all caffeine.
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