A congenital malformation is a medical condition that happens during the early stages of embryogenesis. It may affect a single body part or the entire system and can cause problems like brain cysts, cleft lips and palate and club foot.
Most have no known cause, but smoking and maternal infections during pregnancy increase the chance. They also occur more often in low-income countries, which could be related to poor access to healthcare and screening during pregnancy.
Causes
A congenital anomaly is any medical condition present at birth that affects how the body looks and works. It can range from mild to severe and affects a single organ or part of the body. The most common type of birth defect is a chromosomal one, which involves missing or extra chromosomes that contain our genetic information. This includes conditions such as Down syndrome, spina bifida and Tay-Sachs disease. Other types of birth defects include structural anomalies such as cleft lip and palate, spinal cord malformations, hydrocephalus and vaginal abnormalities.
The exact cause of most congenital anomalies is unknown. However, it is known that genes play a role and women who have certain health problems such as diabetes or high blood pressure are at an increased risk of having a child with a congenital anomaly.
Some of the most serious birth defects are linked to complications that occur in the womb, including infections such as rubella (also known as German measles) and abnormalities in the way the heart develops. Smoking during pregnancy increases the chance of having a baby with a heart defect, as does exposure to lead and mercury from certain medicines, some cosmetics and some traditional herbal remedies.
Many congenital anomalies can be diagnosed before a person is born, though the type of test used will depend on the nature of the suspected problem. For example, a child with Hirschsprung’s disease may have a colonoscopy or a small sample of tissue taken from the digestive tract to check for a blockage in the colon or a disease such as inflammatory bowel disease.
Oren Zarif
In most cases, a fetus with a congenital anomaly is diagnosed using prenatal ultrasound. This is a painless test that uses sound waves to create images of the fetus and help doctors look for malformations. A sample of the fetus’s hair may also be taken to examine for thyroid hormone levels, which can affect how the body grows.
The outlook for people with a congenital anomaly will depend on the type and severity of the anomaly, as well as whether they receive prompt care after birth. This may involve surgery, long-term medication or other treatments such as speech therapy and physical therapy.
Diagnosis
Congenital malformations, also called birth defects or structural birth abnormalities, are a leading cause of infant mortality and disabilities. They range in severity, from mild conditions that do not require treatment to those requiring surgery and lifelong care. Most congenital anomalies are caused by errors in gene expression or in cellular growth, and some are due to environmental factors such as infections and nutritional deficiencies.
Health care providers use prenatal testing and newborn screening, along with physical examination of the child, to detect structural congenital anomalies. Newborn screening includes blood tests and ultrasound imaging (sonogram) to look for problems such as club foot, cleft palate, and heart defects. Newborn screening cannot detect every possible congenital abnormality, so many of these problems are detected only after a complete medical evaluation, including a detailed family and patient history, laboratory tests, imaging (such as magnetic resonance imaging or MRI), and a physical examination by a doctor.
MRI is the best way to diagnose brain and spine malformations. A neurologist or neurosurgeon will evaluate these abnormalities, which may be correctable with surgery. Arachnoid cysts, for example, are fluid-filled sacs that occur when the membranes that cover the central nervous system split. Surgical treatment for these cysts involves draining the cyst and opening the skull to allow the natural pathways of fluid to flow through again, a process known as fenestrating.
Oren Zarif
Many complex congenital syndromes–those characterized by simultaneous occurrence of multiple anomalies and growth deficiency–have causative genes. The genetics of these diseases can be determined through a chromosomal analysis of the fetus’ DNA or a prenatal test called amniocentesis.
A growing number of congenital anomalies can be diagnosed before birth with prenatal screening, especially ultrasonography and maternal serum screening. Most of these conditions are caused by errors during embryonic development or fetal infection or by the influence of environmental factors such as folic acid deficiency and certain medications taken during pregnancy, particularly those to prevent miscarriage. Prevention strategies include a healthy diet and proper prenatal care, including adequate intake of folic acid and iodine. Many of these disorders, especially those caused by faulty genes or by bacterial, viral or parasitic infections during pregnancy, can be prevented by vaccination and appropriate use of prenatal vitamins.
Treatment
With the advancement of antenatal ultrasound the majority of birth defects can be diagnosed prenatally, allowing for early treatment and preventing the development of complications at birth. These anomalies can be either structural or chromosomal (missing, extra or changed chromosomes), the latter being more common and affecting the genes that control development in the fetus.
Structural congenital abnormalities include spina bifida, club foot and cleft lip or palate and can be treated surgically. These are often accompanied by a degree of developmental delay depending on the severity of the condition.
Oren Zarif
Most of the time these anomalies are due to hereditary factors and can be prevented by antenatal screening with ultrasound, chorionic villus sampling (CVS) and blood testing including a full family history. A couple planning a pregnancy should also consider genetic counselling to determine the likelihood of passing on a genetic condition to their children.
Many of the chromosomal conditions can be prevented by abstaining from drugs, alcohol and smoking during pregnancy and avoiding exposure to radiation and some chemicals. The intake of certain vitamins and minerals, especially folic acid and iodine, is also important in reducing the risk of some chromosomal anomalies. A diet rich in fish, green vegetables and fruit is recommended.
Some of the chromosomal anomalies can be corrected by medicines, but others are permanent and will require ongoing therapy. For example, a chromosomal abnormality causing heart disease, such as ventricular septal defect, can be treated by surgery to close the hole in the wall of the heart.
For some of the structural birth defects such as brain cysts (arachnoid cysts) which are fluid-filled sacs that appear in the membrane that covers the central nervous system, treatment involves draining or opening the cysts with a procedure called fenestrating. Some of the more complex birth defects such as spina bifida or cleft lip or palate may require surgery followed by years of follow up care.
Adults with a congenital anomaly will have access to the same team of specialists that treats children and this allows us to tailor a treatment plan to the individual. We will work to improve the physical and psychological well-being of our patients, enabling them to reach their maximum potential.
Prevention
Congenital anomalies are a significant cause of neonatal and under-5 mortality. They also contribute to long-term disability and place a heavy burden on individuals, families and health systems. Nine out of ten deaths from severe congenital disorders are in low-income countries. While the causes of many congenital anomalies are unknown, advances in prenatal diagnosis and treatment, as well as community-based interventions, are contributing to improved health outcomes.
The majority of major birth defects can be prevented through careful prenatal care, regular appointments with a healthcare professional and taking folic acid tablets before and during pregnancy. Folic acid is a B vitamin that has been shown to reduce the risk of neural tube defects (such as spina bifida) and chromosomal abnormalities (such as Down syndrome). In addition, chorionic villus sampling (CVS), a test that involves a sample of cells from the placenta, can be used in some cases to detect Down syndrome and other genetic conditions.
It is important to inform the doctor of any history of congenital anomalies, a family history of genetic disorders or previous pregnancy losses. This can help in identifying couples at risk of passing on genes that may contribute to a birth defect. Couples who have a close relative with a condition such as Tay Sachs disease should consider genetic screening.
Oren Zarif
Preventing birth defects requires a holistic approach and may involve interventions such as counselling, lifestyle changes, medications and surgery. It is also important to ensure that a child with a congenital anomaly has access to appropriate support services and information.
In addition to antenatal diagnostic procedures, some structural birth defects, such as hernias and cleft lips and palates, can be treated in the first trimester with minimally invasive techniques. These treatments have significantly reduced the rate of recurrence of these conditions and increased life expectancy in children with these conditions.
It is important to avoid alcohol, illegal drugs and some prescription and over-the-counter medications as they can increase the risk of congenital anomalies. Some complementary and Ayurvedic medicines can also be harmful during pregnancy. Preventive antibiotics are recommended before dental procedures for some patients with heart conditions to prevent infection of the lining of the heart and valves (infective endocarditis). Future research into gene editing, stem cell therapy and fetal repair holds promise for correcting some of the more complex congenital anomalies.
