There are numerous conditions that fall under the general category of congenital disorders. These include:
- Birth defect – significant structural malformation of a body part
- Congenital physical anomaly – difference or abnormality of a body part that is not considered a problem condition. Most of us have minor physical abnormalities
- Congenital malformation – injurious physical anomalies that include dysmelias, which is when the malformation affects a single limb, or malformation syndromes, when multiple body parts are affected
- Genetic disorder – although considered congenital, some may not become recognized until later in life. Genetic disorders include:
- Single-gene defect: results from abnormalities in both copies of an autosomal gene (recess disorder) or in only one of the copies (dominant disorder)
- Multiple-gene disorder: arises out of abnormalities or deletionsof a few genes located contiguously in a chromosome
- Chromosomal defect: loss or duplication of an entire or larger portions of a chromosome
- Congenital metabolic disease – gene defect, usually inherited, which may affect the structure of body parts or their function
- Sporadic birth defect – unknown cause which cannot be attributed to environmental exposures or genetic abnormalities
There is some overlap between these distinctions. And while most congenital disorders are hereditary, they can also be acquired, as when defects or disorders are caused by physical injuries during delivery or through the use of certain medications during pregnancy.
Birth injuries occur in about 2.7% of births in the US and can affect the life of a newborn over the long term. They include Cerebral Palsy, Erb’s Palsy, Klumpke’s Palsy, Brachial Plexus Palsy, Temporary Paralysis, Brain Damage (most often caused by oxygen deprivation), and Fractured Collar Bone.
Birth injuries may occur when the umbilical chord becomes compressed or twisted, causing oxygen deprivation; due to mechanical trauma, such as when the baby assumes a position other than “head first” or if the baby is too large to pass easily through the birth canal; or due to delivery mistakes, such as when excessive force is applied during delivery or when a needed C-section is delayed.
The Food and Drug Administration (FDA) keeps track of possible problems with medications used by women who are pregnant or breast-feeding. Some perscription drugs that can cause birth defects include Accutane, Crestor, Cytotec, Lexapro, Paxil, Phenytoin, Soriatane, and Terbutaline. But research in this area is limited by ethical dilemmas involved with including pregnant and breast-feeding women in studies.
The use of medications during pregnancy and other intrauterine influences that may cause birth defects are referred to as teratogenic. In some cases, women may have been taking medications before realizing they were pregnant. But in addition to medications, teratogenic incidents may be caused by dietary deficiencies, the use of illegal drugs or alcohol, the ingestion of mercury or other toxins, and infections. Some of the infections that can affect the baby when contracted during pregnancy include syphilis and rubella.
Any damage to the embryo before the third week of gestation is likely to result in its death. The type of birth defect after this is often related to when the embryo is exposed to the damaging influence. For instance, an infection in the mother in the third week may damage the embryo’s heart, whereas an infection in the eleventh week is likelier to cause the baby to be born deaf. After the eleventh week, the fetus’ organs are more developed and less susceptible to teratogenic incidents.
More information on birth defects may be found at the Centers for Disease Control and Prevention’s (CDC) website. Since early 1998, Congress authorized the CDC to collect, analyze, and distribute data on birth defects and to operate regional centers for applied epidemiologic research on their prevention.