by Michele Brown,
There is no question that many of us love our morning cups of coffee, or tea. Caffeine wakes us from our slumber and helps us become alert for the challenging day ahead. The true question, which is very important for a pregnant woman to understand is why, and how, caffeine affects the mother's body -- and the subsequent influence of that cup of coffee, tea or hot chocolate on her unborn child.
Products that contain caffeine, such as coffee, tea, and chocolate are amongst the most popular and widespread products consumed in the world. Its usage may date as far back as 3000 BC, in China. While caffeine is known to be a natural pesticide that paralyzes and kills insects feeding on certain plants, its sustained popularity stems from several unique physiologic and pharmacologic properties.
In other words, caffeine contains chemicals that have a profound stimulating influence on the nervous system, as well as many other human bodily functions.
Caffeine's stimulant properties may:
What happens to the baby when a product containing caffeine is consumed?
Caffeine is absorbed by the stomach and small intestine within 45 minutes of ingestion. It crosses readily to the placenta, accumulating in both the fetus and amniotic fluid. It is metabolized three times more slowly in pregnant women compared to non-pregnant women, allowing for greater, and longer lasting, accumulation in the fetus.
Caffeine also significantly decreases blood flow in the placental villi, (small projections which help increase absorption of nutrients) through constriction of the vessels. Keep in mind that the fetus gets everything it needs from blood flow including nutrition, oxygenation, etc. and, if these vessels become constricted, the fetus gets less of everything needed for growth and development. Consequently, it is thought that maybe this constriction can possibly lead to reduced growth and can be associated with impaired development later on in life—or even stillbirth.
Considering the quantity of caffeine consumed, knowing whether caffeine is harmful in pregnancy is a major public health concern. Many studies have been written about the safety of caffeine in pregnancy most concluding that no malformations have been attributed to caffeine consumption and that most scientists believe that caffeine is not a teratogen (an agent or factor that causes malformations in an embryo) in humans.
However, concerns regarding harmful effects have stemmed from animal and human studies that have shown decreased intrauterine fetal growth, lower birth weights (less than 2500 grams), and skeletal abnormalities. (Vlajinac,1997;Caan, 1989). Other studies have shown no association between caffeine use and adverse outcomes in pregnancy. (Linn, 1982;Bech 2007, Clausson, 2000) Results of these kinds of studies are always questionable because many have been retrospective studies; those being studies that depend upon patient recollection, vary in the amounts of caffeine consumed, have differing sources of caffeine (coffee, tea, chocolate, medication), and have different methods of preparation and serving sizes.
Other studies have correlated specific quantities of caffeine consumed as being the determining factor of risk. (Fenster,1991)
It is known, however, that caffeine is readily transferred into human milk and therefore breast feeding mothers, who consume caffeine, may cause stimulatory effects in younger children.
In 1980, the United States Food and Drug Administration advised pregnant women to avoid caffeine containing foods and drugs, or use them sparingly.