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. . . Is it a Teratogen?
Terato-what?
A teratogen (defined on Dictionary.com) is
There are many teratogens that have been discovered and are still being discovered by scientists. Some examples of these dangerous agents include thalidomide, lead, cocaine, alcohol, x-rays, prozac, antibiotics and tobacco.
Recently, research is being done to determine how harmful caffeine is to an expectant mother's fetus.
Is caffeine something that pregnant women should refrain from completely?
Or is it something that is okay to have in moderation, if not whenever it is desired?
Don't Create a Monster...
Think of the story of Wicked. Because the mother drank a green elixir (an alcoholic drink) while she was pregnant, her daughter Elphaba was born with a green complexion and people came to think of her as an “unnaturally green” monster.
But where is this talk of creating a monster coming from?
When we split the word teratogen into its Greek origins,
“teras” means monster, and “gen” means create.
However, it is not as if someone consumes a teratogen and out pops a baby monster. Basically, this just causes abnormal development of the fetus to take place. The extent of the birth defects or abnormalities relate directly to what and how much of the teratogen was taken in. In terms of caffeine, scientists have not fully deduced how harmful of a teratogen it really is and the exact amounts that lead to certain deformities or malformations in a fetus.
Why Caffeine? It seems so harmless.
Why caffeine? Why not talk about an obvious teratogen like street drugs or alcohol?It is a normal drug just like Tylenol or Aspirin, but it is potentially harmful.
We are not all heroin or marijuana users, but almost every person will consume some form of caffeine in their lifetime. It is a social drug with many beneficial effects. Whenever caffeine is mention, most people think of a freshly brewed cup of coffee. The advantageous effect is clear here: it gives someone the energy they are going to need for the day.
The negative effects that caffeine has on babies are not extreme, but studies do show that there is room for defects to develop.
Unfortunately, research is still very ambiguous and not much has been done in recent years to be able to definitively conclude how dangerous of a teratogen caffeine is.
It never hurt to take caffeine before I was pregnant, though.
Actually....
There are many physiological effects of caffeine that are not exactly healthy for the average person. They are not harmful, but it is a stimulant to many of the body's processes.
Physiological Effects of Caffeine:
-Accelerates heartbeat
-Dilates vessels
-Speeds up breathing rate
-Increases general rate of metabolism
-Postpones fatigue
-Increases production of stomach acid and urine (it is a diuretic)
-Relaxes smooth muscles; notably the bronchial muscle.
-Can aggravate any present conditions (i.e. diarrhea)
In general, caffeine is simply psychologically and physically stimulating
By the way, caffeine is not only found in coffee! It can be contained in other beverages and foods, such as teas, certain types of aspirins (Excedrin) and over-the-counter drugs, soft drinks, and chocolate. Although they are trace amounts, it is important to know of its presence.
The following image shows the approximate amounts of caffeine that can be found in each of these forms:
Academic Research
Prenatal Development
There has been no evidence to suggest that coffee has an effect on women's fertility. Due to ethics, little to no research has been done to human fetuses. However, some studies have found conclusive evidence in experiments done with animals, such as rats and chicken embryos. One such example was done by a student at Michigan when he injected 16 different chicken embryos with different dilutions of caffeine and Vitamin A, a known teratogen. Those that received 100% caffeine died by the second day, but those that had diluted solutions of caffeine (only .009%-6% of the solution was caffeine) seemed to develop normally by the third day. Thus, this student proved that higher amounts of caffeine led to more adverse effects in the fetus.
A different study was done at the University of Wisconsin Medical School that focused more on the cardiovascular (heart/blood vessel) development of four chicken embryos. For this study they injected two of the embryos with caffeine after 3-3 1/2 days of incubation. For the purposes of comparison, two additional embryos were left untouched and treated as normally developing embryo. The results "produced a dose-dependent decrease in end diastolic volume, stroke volume, cardiac output, and ejection fraction." (Bruyere, 1987) This means that the caffeine negatively affected any of the systems that related to the heart. Blood pressure declined, made for inadequate oxygen supply to pass through the vessels, and decreased the amount of blood that was being pumped out of the heart. In addition to all of these adverse effects, the heart rate increased by 30% (in ONE hour) regardless of the caffiene dose.
Similar results were found in rodents, including a higher rate of deformity in the body. However, the amount of caffeine given to the rats would be at toxic levels to humans, approximately 50-70 cups per day. Hence, this greatly decreases the chances for malformities in human fetuses because it is quite unlikely that any woman is going to drink this much coffee in one day. But it is important to keep in mind that the number of spontaneous abortions and stillbirths increased with an increase in the amount of caffiene consumed. Across five studies, researchers found that 2% of all previously mentioned abnormalities were related to coffee. (Nehlig, 1994)
In the same study done by Dr. Astrid Nehlig in 1994, he found there is a "correction factor" when finding the difference between human and animal consumption: metabolic body weight. What this means for us is that although 20 mg of caffeine given to a rat proportionately equals 17 cups for the average man, it is actually comparable to 3-4 cups of coffee when a person's metabolicbody weight is taken into account (Nehlig, 1994).
Possibly the most helpful result of Nehlig's study was the effects caffeine can have on the placenta. He found that the caffeine causes the blood vessels to contract, but not the umbilical cord. The study showed the blood flow coming from inside the placenta (in the intervillous space) is significantly restricted/diminished after only 2 cups of coffee.
Postnatal Development; Caffeine and Breastfeeding
When Nehlig studied rats, he found caffeine alters essential amino acids in the brain, such as catecholamines (epinephrine, noradrenaline, dopamine), tyrosine (which works with the catecholamines to create neurons), tryptophan, serotonin, and other "cyclic nucleotides". These changes can caused harm to the mental and social development of the rat. Some of the rats would not interact with other rats or do the assigned tasks. In humans, a low amount of serotonin and a low protein diet can result in many disorders such as clinical depression, IBS, hyperactivity, tinnitis, and in rare occasions, SIDS. (Nehlig, 1994).
A study done by Drs Watkinson and Fried at Carleton University observed the effects of caffeine on 286 pregnant women. For many, coffee made up more than half their caffeine intake, while the other half was from teas and medication. The results of the research were as follows:
"The most marked effect associated with heavy caffeine use (over 300 mg daily) in the present study was the reduced birth weight and the smaller head circumference that persisted after statistically controlling for other potentially contributing factors" (Watkinson, 1985). The babies born from the women that had a high intake of caffeine had a head circumference that was 1.1 centimeters smaller than that of a normal infant. Additionally, the babies that were exposed to a high intake of caffiene weighed less than normal infants by an average of 379 grams.
During the first trimester, most women refrain from drinking coffee because of the nausea it can induce, but the nausea associated with caffeine usually dissipates by the third trimester, so woment revert to drinking about 2-3 cups a day. However, This is not a good action beccause it is during the third trimester that the fetus has a growth spurt, and caffeine can stunt it.
Postnatal development can show effects of caffeine as well. Breastfeeding studies are still quite inconclusive, but the American Academy of Pediatrics has listed that it is acceptable for the mother to consume caffeine while breastfeeding. The half-life of caffeine for people is 2.5-6 hours; in other words, it does not take long for the caffiene to fade away in an adult person. For infants, though, the time it takes for the caffeine to perish can range from 40-130 hours since their bodies are less developed this early on. Consequently, if a mother who breastfeeds is drinking 2-3 cups of coffee per day and/or consuming other foods which have caffeine in them, she may have a baby that is abnormally restless or irritable (Watkinson, 1985).
Conclusions
There have been many separate studies done on the effects of caffeine on a fetus, but the results are still very inconclusive. While this is true, almost all researchers agree that a cup a day will not do any harm. It has the potential for harm, so caution must be used when taking this drug. We have classified caffeine as a weak teratogen, but it should not be combined with other social drugs such as alcohol and tobacco.
So...
Go ahead and have that cup of coffee and a chocolate bar!
Don't forget; it only hurts the ones you love the most. . .
References:
Bruyere Jr., Harold, Bernard J. Michaud, Enid F. Gilbert, and John D. Folts. (2006). The effects of cardioteratogenic doses of caffeine on cardiac function in the 3-day chick embryo. Journal of Applied Toxicology, 7, 197-203. Retrieved October 9, 2007, from http://www3.interscience.wiley.com/cgi-bin/abstract/112228034.
Caffeine. (2007). Retrieved October 15, 2007, from http://www.faqs.org/nutrition/Ca-De/Caffeine.html.
March of Dimes. (2007). Caffeine in Pregnancy. Retrieved October 1, from http://www.marchofdimes.com/professionals/14332_1148.asp.
Nehlig, Astrid, and Gérard Debry. (1995). Potential teratogenic and neurodevelopmental consequences of coffee and caffeine exposure: A review on human and animal data. Neurotoxicology and Teratology, 16, 531-543. Retrieved October 8, 2007, from http://findarticles.com/p/articles/mi_m0887/is_n2_v14/ai_16722420.
Saved by the Bell. (2006). Retrieved October 8, 2007, from http://www.youtube.com/watch?v=ljtuGoIIKGs.
Teratogen. (2002). Retrieved October 14, 2007, from http://dictionary.reference.com/browse/teratogen.
Watkinson, Drs. B., and P. A. Fried. (1985). Maternal Caffeine Use Before, During and After Pregnancy and Effects Upon Offspring. Neurobehavioral Toxicology and Teratology, 7, 9-17. Retrieved October 3, 2007 from http://www.chem-tox.com/pregnancy/coffee.htm.
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