This research examines the phenomenon of teratogens, or factors external to the physical experience of pregnancy, during the period of gestation, which may affect pregnancy outcomes by fostering congenital birth defects in newborns. The research will set forth the clinical context in which teratogenic agents achieve relevance for the course of pregnancy in the modern period, and then discuss the impact that concern about teratogens may have on efficient and prudent pregnancy management.
On the face of things, the generally accepted definition of a teratogen would appear to be straightforwardly informative. Mosby's initially defines a teratogen as "any substance, agent, or process that interferes with normal prenatal development, causing the formation of one or more developmental abnormalities in the fetus" (Teratogen, 1998, p. 89). However, amplification of the definition demonstrates the complex functionality of teratogens: What a teratogen is cannot be definitively stated. How it will strike cannot be predicted absolutely, though embryos appear to be most vulnerable between weeks three through twelve of gestation, "when differentiation of the major organs and systems occurs" (p. 89).
The literature contains specific recommendations against use of certain otherwise beneficial pharmaceuticals based on their teratogenic effects on pregnancy outcomes. But repeatedly in studies that form the basis of such recommendations, problems with methodology emerge because of the difficulty of establishing human-subject experimental and control groups for administration and nonadminstration of suspected teratogens. One example comes from a study conducted in Sri Lanka (De Silva & Others, 1999), where hookworm infection, which has iron-deficiency anemia as a side effect, is common. Obviously maternal anemia can be harmful to a fetus, but the question researchers asked was whether the risk of anemia would be outweighed by the risk of congenital ...