Teratogenetics: Caffeine as a Teratogen

The purpose of this paper is to identify the teratogenetic affects of caffeine in unborn children and breast feeding children. The following topics will be discussed: Risk of congenital anomalies, risk of spontaneous abortion, risk of low birth weight and preterm labor as well as, the critical period of the teratogen, short term and long term affects, and the changing danger of the teratogen relating to technological advances. The necessary dosage for teratogenetic impediment of the healthy development of unborn children, as well as the steps that can be taken to prevent this will also be included. Furthermore, and quite possibly most relevant to the topic of the teratogenetic effect of caffeine, is its ability to potentiate the teratogenetic effects of other substances. Keywords: Coteratogen, critical period, threshold

I chose caffeine as my teratogen because it is considered the most widely used drug in the world. As the most widely used drug in the world I thought it would be interesting to see its teratogenetic affects on the children of mothers ingesting it while pregnant. The typical eight ounce cup of coffee contains 150 mg of caffeine. The average American consumes at least three times that much per day in one form or another.

The critical period of caffeine as a teratogen depends on whether or not it acts alone or if it is a coteratogen with another substance. If it is a coteratogen then the critical period becomes that of the second teratogen. If it is acting alone then the most significant affects during gestation happen generally around the third trimester. This period is most closely related with the defect of Low Birth Weight in newborns. Also a non-significant trend was noted in the third trimester between increased caffeine consumption and preterm birth.

The threshold for caffeine is relatively high and that is a main contributor to caffeine being generally regarded as a safe drug and having little to no teratogenic affect. The threshold varies between individuals and different races but the average is the equivalent of about twelve cups of coffee in one day. This is roughly equal to 1800 mg of caffeine. This threshold however, generally only applies to defects from caffeine alone. When combined with a coteratogen the threshold lowers significantly.

Other teratogens that frequently act as coteratogens to caffeine are alcohol and cigarettes. One common defect relating to these teratogens is the prevalence of Neural Tube Defects in newborns. NTDs are also the second most common defect in newborns in the United States. This however cannot be attributed solely to the affects of the aforementioned teratogenic substances. Caffeine has been proven to potentiate the effects of alcohol and cigarettes rather than induce its own chromosomal aberrations, and also transforms sub lethal damage of mutagenic agents into lethal damage. Caffeine also inhibits DNA repair, so any damage to DNA by other teratogens can be exacerbated by combining the exposure with caffeine.

The effects of caffeine inhibition of healthy development are comparatively mild. There are few severe affects in the social and cognitive fields. The affects that did surface would be due to the physical effects of the teratogen. These include but are not limited to: low birth weight, preterm labor and in the cases of those that did not survive long enough to be born, spontaneous abortion. Exposure to significant levels of caffeine in utero has been associated with vasoconstriction and cardiac arrhythmias.

While the developing child can undoubtedly be affected by excess caffeine we must also recognize the affect on the mother. This includes the effect of caffeine on the ability of a woman to become pregnant in the first place. High caffeine drinkers are half as likely to conceive per menstrual cycle. The effects of caffeine consumption also continue to affect the mother and child during pregnancy and after birth. Caffeine normally has a half life of three hours. During the first trimester of pregnancy, however, the half life of caffeine increases to 5.6 hours, and continues to increase to a high of 18 hours by the 35th week of pregnancy. This is attributed to the changing hormone levels during pregnancy.

As for the child, the half life of caffeine in newborns can be as long as 40-130 hours because of the immature metabolic pathways utilized in caffeine excretion. But no one would give caffeine to a newborn; so how do they come into contact with it? Newborns receive caffeine because it is excreted in breast milk. The peak of caffeine excretion is one hour after its consumption by the mother. So a mother who drinks a cup of coffee will then pass on the caffeine to her newborn through breast milk. Additionally if the rate of caffeine consumption by the mother is too high the caffeine will begin to replace iron in the breast milk. As the rate of caffeine consumption increases so does the possibility of the teratogenic affect of it. Caffeine is become more and more prevalent in our daily lives and is readily available to anyone wishing to consume. This could have increasingly dangerous side effects in regard to the healthy development of babies. The teratogenic affects of caffeine can be avoided however, as long as the parents assume responsibility for their actions and limit their consumption of caffeine during pregnancy and after while still breastfeeding. Caffeine though ever prevalent in the lives of nearly everyone can be consumed in a responsible manner with regard to its coteratogenic affect with other substances.

Reference:

http://www.fetal-exposure.org/resources/index.php/1997/10/01/caffeine-and-pregnancy/ Maternal Caffeine Intake, Select Metabolic Gene Variants, and Neural Tube Defects (NTDS). (print) http://www.nvp-volumes.org/p2_4.htm