April 14, 2010
Environmental Sources of Birth Defects
Environmental agents that can cause deviations in normal development and can lead to serious abnormalities or death are called teratogens. It is usually something in the environment that the mother may be exposed to during her pregnancy. It could be a prescribed medication, a street drug, alcohol use, or a disease present in the mother which could increase the chance for the baby to be born with a birth defect. In this paper I will be exploring different types of teratogens, and their effects on the fetus.
There are many different factors surrounding the threat of certain teratogens and the time of exposure. Depending on an organisms developmental stage at the time of exposure the organisms susceptibility could be higher or lower. The most dangerous time for teratogenic exposure is during the first two weeks of pregnancy, many women are not even aware that they are pregnant, teratogenic exposure may destroy the organism at this time. Also each body system, or limb is most vulnerable at its initial time of growth spurt . Susceptibility to teratogens depends also on the mothers nutritional and physiological state. Teratogenic effects become intensified if the mother is unhealthy.
One of the biggest environmental sources of birth defects is prescription or illegal drugs.
Marijuana. Marijuana crosses the placenta to your baby. Marijuana, like cigarette smoke, contains toxins that keep your baby from getting the proper supply of oxygen that he or she needs to grow. Studies of marijuana in pregnancy are inconclusive because many women who smoke marijuana also use tobacco and alcohol. Smoking marijuana increases the levels of carbon monoxide and carbon dioxide in the blood, which reduces the oxygen supply to the baby. Smoking marijuana during pregnancy can increase the chance of miscarriage, low birth-weight, premature births, developmental delays, and behavioral and learning problems.
Cocaine. Cocaine enters the baby's blood circulation. The elimination of cocaine is slower in a fetus than in an adult. This means that cocaine remains in the baby's body much longer than it does in your body. during the early months of pregnancy, cocaine exposure may increase the risk of miscarriage. Later in pregnancy, cocaine use can cause placental abruption. Placental abruption can lead to severe bleeding, preterm birth, and fetal death. women who use cocaine during their pregnancy have a 25 % increased chance of premature labor. Babies born to mothers who use cocaine throughout their pregnancy may also have a smaller head and have their growth hindered. Babies who are exposed to cocaine later in pregnancy may be born dependent and suffer from withdrawal symptoms such as tremors, sleeplessness, muscle spasms, and feeding difficulties. Some experts believe that learning difficulties may result as the child gets older. Defects of the genitals, kidneys, and brain are also possible.
Heroin. Heroin is a very addictive drug that is passed to the baby during use. Because this drug is so addictive, the unborn baby can become dependent on the drug. Using heroin during pregnancy increases the chance of premature birth, low birth weight, breathing difficulties, low blood sugar (hypoglycemia), bleeding within the brain (intracranial hemorrhage), and infant death. Babies can also be born addicted to heroin and can suffer from withdrawal symptoms. Withdrawal symptoms include irritability, convulsions, diarrhea, fever, sleep abnormalities, and joint stiffness. Mothers who inject narcotics are more susceptible to HIV, which can be passed to their unborn children.
Hallucinogens. PCP and LSD are hallucinogens. Both PCP and LSD users can behave violently, which may harm to the baby if the mother hurts herself. PCP use during pregnancy can lead to low birth weight, poor muscle control, brain damage, and withdrawal syndrome if used frequently. Withdrawal symptoms include...