The adult body is capable of processing and filtering many substances that may otherwise be harmful. On the other hand, a tiny, developing fetus is highly susceptible to environmental factors. While many causes of birth defects and fetal abnormalities remain unknown, there are several factors that have been scientifically proven to be problematic.
Smoking can cause miscarriage, premature birth, slow growth and stillbirth. It also increases the chance of developing placenta previa, a condition in which the placenta grows over the cervical opening. Smoking may harm the unborn baby's lungs and cause birth defects.
Fetal Alcohol Syndrome is a condition directly caused by the consumption of alcohol during pregnancy. It may cause slow and abnormal fetal growth, physical birth defects, nervous system and brain defects, deafness and hearing loss, and motor skill dysfunction.
As outlined in "Your Pregnancy, Week by Week" by Dr. Curtis and Judith Schuler, illegal drugs have many known effects on a fetus. The effects of cocaine include major birth defects, miscarriage, low birth weight, physical deformities, and heart and organ abnormalities. Cocaine use increases the risk of placental abruption, cocaine addiction in the fetus, and maternal death. Marijuana use can cause learning and behavioral problems. Ecstasy has been linked to learning and memory disabilities. Methamphetamine use may cause IUGR, a condition that impairs fetal growth and could result in stillbirth or the delivery of a low birth weight baby. Heroine use during pregnancy may cause premature birth and congenital abnormalities.
According to Dr. Curtis and Schuler, many legal drugs can be detrimental to an unborn child. The synthetic forms and derivatives of Vitamin A, such as retinoids, can cause birth defects and fetal death. Anti-thyroid drugs may cause goiters and hyperthyroidism in the unborn baby. ACE-inhibitors increase the risk of fetal death. In her book, "The Mother of All Pregnancy Books," Anne Douglas explains that morphine and Demerol may cause premature birth, abnormal growth during the third trimester, and congenital malformations. Acetaminophen increases the child's risk of kidney failure. Aspirin may cause clotting and cardiac problems, and low birth weight. Cough medicines containing dextromethorphan increase the risk of birth defects. Ephedrine may cause heart-rate problems and birth defects. Cardiac malfunction is an effect of ibuprofen. Accutane causes major birth defects. There are many over-the-counter and prescription drugs that may be harmful to an unborn baby. Talk to your doctor about all medications you are taking.
Maternal Disease and Illness
There are many fetal effects if the mother contracts Rubella during her pregnancy, including deafness, organ abnormalities, heart defects, and cataracts. The developing fetus is sensitive to temperature changes and can be negatively effected by a high maternal fever. Syphilis can cause skin problems and fetal death. Dehydration and fever from the flu are also concerns for the fetus. (Reference 3)
Curtis and Schuler also discuss the possible effects of other factors that may harm the fetus. High levels of caffeine can cause low birth weight, lung problems, mental disabilities, microcephaly and birth defects. Experts recommend no more than 200 mg of caffeine per day during pregnancy. Glues and solvents may cause low birth weight, facial and heart defects, joint issues and small head size. Participation in impact sports or high-danger activities may cause injury to the fetus or placenta. Examples include scuba diving, football, horseback riding, water skiing and basketball. Jet skiing, snowmobiling and motorcycle riding should be avoided during pregnancy.