What are Congenital Abnormalities?
Congenital abnormalities are defined as functional or structural abnormalities that occur at or before birth. These defects occur while a baby is developing in the mother's body. An estimated 300,000 newborns die within a month of birth each year worldwide as a result of congenital abnormalities, which are also important causes of chronic illness and disability in children. Some of the common congenital abnormalities include clubfoot, hip dysplasia, spina bifida, cerebral palsy, leg length discrepancy, Perthes, scoliosis, gait abnormalities, heart defects, neural tube defects, and Down syndrome. Congenital abnormalities are also referred to as birth defects, congenital disorders, congenital anomalies, or congenital malformations.
Causes and Risk Factors of Congenital Abnormalities
Some of the causes and risk factors of congenital abnormalities include:
- Genetic factors: Genes play a crucial role in several congenital abnormalities. This occurs mostly through inherited genes that code for an abnormality or may result from sudden changes in genes known as genetic mutations.
- Infections: Maternal infections such as rubella and syphilis are important causes of congenital abnormalities in low- and middle-income countries.
- Environmental factors: Exposure of the mother to certain chemicals and pesticides, certain medications, tobacco, alcohol, and radiation at the time of pregnancy may increase the likelihood of having a foetus or newborn affected with congenital abnormalities.
- Maternal nutritional status: Folate insufficiency in the mother increases the likelihood of having a child with a neural tube defect, while increased vitamin A consumption may affect the normal growth of a foetus or embryo.
- Demographic and socioeconomic factors: An estimated 94 per cent of serious congenital abnormalities occur in low- and middle-income countries. This indicates a possible lack of access to adequate nutritious foods, excessive exposure to agents or factors such as alcohol and infection, or very poor access to screening and healthcare by pregnant women.
Detection of Congenital Abnormalities
Most congenital abnormalities can be identified prior to birth, during birth, or later in life through medical screening. These screenings include:
- Preconception screening: This screening can be employed to detect women who are at risk for particular disorders or of transmitting a disorder to their children. Preconception screening involves obtaining familial histories and conducting a genetic test called carrier screening that helps to determine if a healthy individual is a carrier of a recessive genetic disorder. Infection screening is also done to determine if a woman has a urinary or sexually transmitted infection or other types of infections that can be dangerous to her or her foetus. Vaccination status is also checked during this screening to assess a woman’s immunity status to diseases such as rubella that can cause birth defects or miscarriage.
- Peri-conception screening: This screening may involve the use of:
- Ultrasound scans are used to detect Down syndrome and other structural anomalies during the first trimester and to detect serious fetal abnormalities during the second trimester.
- Maternal blood screening for placental markers is useful to predict the likelihood of neural tube defects or chromosomal abnormalities.
- Cell-free fetal DNA (cffDNA) testing is used to screen for several other chromosomal abnormalities.
- Diagnostic tests such as amniocentesis and chorionic villus sampling (CVS) are done to diagnose infections and chromosomal abnormalities in women at high risk.
- Neonatal screening: This is a newborn screening that involves clinical examination and screening for abnormalities of the blood, hormone and metabolism disorders, heart defects, and hearing problems in a newborn. Early detection of such congenital anomalies can prevent them from progressing towards visual, auditory, physical, or intellectual disabilities and facilitate life-saving treatments.
Prevention of Congenital Abnormalities
The prevalence of certain congenital abnormalities can be decreased by eliminating risk factors and reinforcing protective factors through measures, such as:
- Changing your lifestyle by abstaining from alcohol, smoking, or street drugs
- Consuming healthy foods such as fruits, vegetables, whole-grain products, lean meat, and maintaining a healthy weight
- Safeguarding yourself from viral and bacterial infections that may affect pregnancy
- Staying away from exposure to environmental hazardous substances, such as pesticides or heavy metals during pregnancy
- Consuming sufficient dietary vitamins and minerals, especially folic acid that can help prevent birth defects
- Keeping your stress level under control as high stress can affect your pregnancy
- Managing health problems you may have, such as high blood pressure, thyroid problems, depression, or diabetes through prescription drugs, weight management, and diet
- Engaging in physical activity as it can help reduce your risk of developing certain health conditions, such as diabetes and high blood pressure
- Screening for infections, particularly varicella, syphilis, and rubella, and consideration of necessary treatment
- Ensuring you are up-to-date with all your vaccinations, such as tetanus, diphtheria, and acellular pertussis (Tdap) that can help prevent structural birth defects and other congenital anomalies
- Getting a preconception check-up and talking to your doctor about health conditions that can affect your pregnancy
- Informing your doctor about any medicines or supplements that you may be taking that may affect your pregnancy
Treatment for Congenital Abnormalities
Many cases of structural congenital abnormalities such as club foot, developmental dysplasia of the hip (DDH), cleft lip and palate, leg length discrepancy, gait abnormalities, scoliosis, and spina bifida can be surgically corrected with the intervention of paediatric surgery in early life. Cost-effective, simple, and non-invasive treatment is also available for certain medical conditions such as clubfoot.
Treatment for deformities of the limb may involve orthotics, prosthetics, physical therapy, and corrective surgery. Advances in medical technology have also enabled some surgeries to be performed in utero (when the baby is in the womb), such as surgery to treat spina bifida, which has shown considerable improvement in the outcome when compared with the spina bifida surgery performed after birth.
Suitable treatment with rehabilitation services is also needed for congenital structural abnormalities manifesting themselves in the post neonatal period.