A congenital disorder is any disease or abnormality that is present either at birth or prior to birth. Types of congenital disorders range from genetic disorders like Down syndrome to physical abnormalities like microcephaly that result from alcohol exposure during pregnancy. Other commonly used terms include congenital anomalies, congenital malformations and birth defects. Congenital disorders affect an estimated 3 to 4 percent of babies in the United States each year. Worldwide, more than a quarter of a million infants die within a month of birth due to congenital disorders.
Definition & Facts
A wide variety of causes can contribute to the presence of a birth defect, though more is known about some types of congenital disorders than others. At this point, just half of all known birth defects have been studied sufficiently to understand their root causes.
Examples of well-known and heavily studied congenital disorders include Down Syndrome, cleft lip and cleft palate, congenital heart defects, cystic fibrosis, and neural tube defects. Congenital disorders occur more frequently in countries where health care resources are scarcer though detection, treatment, and prevention of congenital disorders worldwide have progressed due to global initiatives sponsored by international groups like UNICEF and the World Health Organization (WHO).
Symptoms & Complaints
- An internal abnormality (such as a heart murmur) that is observed during a physical examination
- If a baby has a congenital heart defect, he or she may appear blue due to cyanosis and breathe rapidly
- Visible physical abnormalities, as in the case of Down syndrome, club foot, or cleft palate/lip.
- Developmental difficulties are detected during exams or in early classes.
- Pain that requires further testing (such as with the blood disorder, sickle-cell disease).
There are many different causes of congenital disorders. If the mother is malnourished during pregnancy, the risk of certain birth defects rises greatly. If either parent abuses alcohol or drugs prior to conception or if the mother continues to use drugs, alcohol, tobacco products or certain medications during pregnancy, there is a greater risk of a congenital disorder for the fetus.
Exposure to potentially unsafe agents during pregnancy contributes to the onset of many congenital disorders. If the mother is exposed to environmental toxicants such as pesticides, chemicals, runoff or fumes from mines or smelters, and other such toxins, there is a greater risk to the infant.
Certain demographic characteristics of the parents can contribute to the onset of congenital disorders. When women become pregnant very early in life or, alternately, very late in life (advanced maternal age), there is an increased risk of certain birth defects. When blood relatives (consanguinity) conceive a child together, birth defects are more likely. Certain ethnic populations (such as Ashkenazi Jews) are more at risk for specific kinds of genetic disorders than others.
The genetic makeup of the parents and any genetic mutations one or both may possess cause inherited genetic disorders. Types of inherited disorders include autosomal recessive disorders, autosomal dominant disorders, X-linked recessive disorders, X-linked dominant disorders, among others.
Diagnosis & Tests
It is possible to test for the presence of a number of known birth defects. Diagnostic testing can be done at several points, including genetic testing that occurs prior to conception. These tests analyze any genetic mutations present in one or both parents and can help prospective parents determine the risk of their child having birth defects.
Prenatal tests occur following conception and can determine how the pregnancy is progressing and detect certain birth defects (such as Down syndrome) during particular periods during the pregnancy. There are a number of tests the physician may recommend, including these:
- Amniocentesis. An amniotic fluid sample from the uterus is analyzed.
- Ultrasound. Sound waves allow the baby's development to be viewed at different points during the pregnancy.
- Chorionic villus sampling (CVS). A small cluster of placental cells is analyzed for possible presence of congenital disorders.
- Maternal blood tests (cell-free fetal DNA testing). Since the baby's DNA enters the mother's bloodstream after conception, the mother's blood can also be analyzed for birth defects and there is less risk to the fetus since the procedure is non-invasive.
Finally, neonatal tests may be conducted on the newborn. Testing the newborn for the presence of hearing problems, cardiovascular disease, lung disease, blood disorders, and issues with the glands, and other possible congenital abnormalities can make it possible to provide prompt treatment and minimize the severity of birth defects that may be present.
Treatment & Therapy
Treating congenital disorders can take different forms. If the congenital disorder is discovered in utero, the couple may decide not to pursue pregnancy or not to permit a pregnancy that is in progress to continue to term. For some birth defects, it is possible to perform fetal surgery. This may be an option for fetuses that have congenital heart defects and spina bifida. Types of surgery include open fetal surgery and fetoscopy, the latter of which is minimally invasive.
Treatment may also address issues post-delivery during neonatal surgery (such as with cleft lip/palate or some forms of heart and lung abnormalities). Other issues can be treated with therapy such as providing physical therapy and prosthetic limbs for infants born with missing limbs. In some cases, such as fragile X syndrome and Down Syndrome, it is possible to address the intellectual and behavioral disabilities these congenital disorders cause through providing life-long speech therapy, special education, behavioral therapy, and in some cases, psychiatric medication.
Prevention & Prophylaxis
While not all birth defects can be prevented or even treated, many that are linked to malnutrition, drug use, and exposure to toxins are preventable. It is important for parents to keep themselves healthy before and throughout the pregnancy. This is particularly important for the mother, who can avoid some birth defects by eating well; avoiding drugs, alcohol, and environmental pollution; taking appropriate supplements; and practicing good self-care.