Common Birth Defects

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Each year in the United States, about 150,000 newborns have birth defects ranging from mild to life threatening. The three leading categories of birth defects are structural/metabolic, congenital infections, and other conditions. While progress has been made in the detection and treatment of newborn birth defects, they remain the leading cause of death in the first year of life. Common birth defects are often the result of genetic and environmental factors, but the causes of well over half of all birth defects are currently unknown. The following is a brief sketch of the most commonly noted birth defects.

Congenital Heart Defects

What are congenital heart defects?
Congenital heart defects can affect any of the different parts or functions of the heart, which is responsible for pumping blood through the body. Defects can include holes in the wall of the heart, a heart that beats too quickly or too slowly, valve defects that prevent blood from flowing smoothly, or other malformations that prevent the heart and circulatory system from functioning efficiently.

How common are congenital heart defects?
Heart defects are among the most common birth defects. Each year more than 25,000 U.S. infants are born with heart defects. These defects can be very mild, exhibiting no symptoms for many years, or they can be severe, requiring immediate attention at birth. In most cases, doctors cannot pinpoint what causes a baby's heart to develop abnormally. So far, scientists believe there are both environmental and genetic factors that contribute to congenital heart defects. Women who contract rubella or some other viral infections may have a greater risk of having a baby with a heart defect. Certain chronic illnesses in the mother, such as diabetes, can increase the risk of congenital heart defects in the baby. Doctors have identified certain drugs, such as some taken for acne and depression, as risk factors. Studies have also shown that cocaine or alcohol use during pregnancy can increase the risk of heart defects in the developing baby.

How is the baby affected by congenital heart defects?
A defect in the heart can impair its ability to circulate oxygenated blood through the body. The baby may exhibit a variety of symptoms, such as a rapid heartbeat or breathing difficulties, especially during exercise. In infants, this tendency to tire easily may interfere with nursing and result in poor weight gain. Some children with heart defects show a pale grayish or bluish coloring of the skin. There are some babies and children with heart defects who experience no symptoms; the defect may be diagnosed when the doctor hears an abnormal sound called a murmur. Some defects are so slight that the baby may appear healthy for many years after birth.

What are the treatment options for congenital heart defects?
The prognosis for children with congenital heart defects has improved significantly in the past 40 years. Today, most heart defects can be corrected, or at least helped, by surgery, medicines, and devices such as pacemakers. There are prenatal tests that can detect many heart defects before birth. A special form of ultrasound may show a fetal heart that is beating too quickly or too slowly. In that case, medications may be able to restore a normal heart rhythm. Surgical interventions after birth have also improved. Until recently, it was often necessary to make temporary surgical repairs in infancy and postpone full corrective surgery until later in childhood. Today, half of children who require surgery to correct a heart defect can undergo the procedure before age 2.

Clubfoot

What is clubfoot?
Clubfoot describes a range of foot and ankle abnormalities. The defects can be mild or severe and can affect one or both feet. An affected foot points downward, with the toes turned in. If both feet are affected, as they are in about half of all cases, the toes will turn in toward each other rather than pointing straight ahead. The foot bones, ankle joints, and ligaments of the foot may be abnormal or tight, making it difficult to bring the foot into a normal position. There are also milder foot abnormalities that may appear similar to clubfoot.

How common is clubfoot?
Clubfoot is one of the most common birth defects. Each year, about 5,000 U.S. babies are born with the most severe forms of clubfoot. Clubfoot is almost twice as likely to affect boys. Milder forms of foot malformation are even more common and tend to affect both sexes equally. In most cases, doctors can't pinpoint what causes clubfoot. It was once thought that the malformations were caused by a twisted or cramped position in the mother's womb. But many scientists today believe clubfoot starts early in pregnancy, probably around the 10th week of gestation. Heredity and some environmental factors, such as smoking during pregnancy, are likely at the root of the defect.

How is a child affected by clubfoot?
Clubfoot is not painful in infancy. The child is not affected until he tries to stand or walk. Without treatment, the poorly aligned foot and ankle can't move normally, resulting in an awkward gait. If both feet are affected, the child may walk on the balls of his feet or on another part of the foot such as the side or top. This can result in sores and hard calluses and may even interfere with the growth of the entire leg.

What are the treatments for clubfoot?
The disabling effects of clubfoot can be avoided with early treatment. Generally, treatment will begin soon after birth. The most common treatment is a series of casts, which gradually train the foot to stay in the proper position. It can take three to six months of casting to straighten the foot. Other cases will require surgery to place the bones in proper position and to open and lengthen joints. This surgery often takes place around the age of 6 months. Because clubfoot can recur, frequent checkups during the first seven years of life are recommended.

Down Syndrome

What is Down syndrome?
Down syndrome is a genetic disorder. It includes a combination of birth defects including mental retardation, characteristic facial features, and often a range of health issues, such as impaired hearing, impaired vision, and heart defects. It is caused by the presence of an extra chromosome.

How common is Down syndrome?
Down syndrome is one of the most common genetic birth defects, affecting about one in every 1,000 babies. In the United States, there are approximately 350,000 individuals with Down syndrome. Mothers who are over age 35 are at greater risk of having a baby with Down syndrome. Prenatal testing can diagnose or rule out this disorder.

How does Down syndrome affect the child?
All children with Down syndrome are affected with some degree of mental retardation. The degree of retardation varies widely, although it's usually in the mild to moderate range. The physical characteristics of the baby are not good indicators of the level of mental retardation. Down syndrome produces characteristic facial features. A child may have eyes that slant upward. Her mouth, nose, and ears may be small. Some children have short necks and small hands with short fingers. Children with Down syndrome generally can achieve most of the major milestones of childhood, such as walking, talking, and using the toilet, although often they do these things later than other children. Special education programs are often recommended, but many Down syndrome children are able to participate with their typical peers in the classroom and in extracurricular activities. Down syndrome often comes with a variety of medical problems, including heart, vision, and hearing difficulties.

What treatment is available for Down syndrome?
There is no cure for Down syndrome. However, with early intervention and special education, many babies born with Down syndrome can grow up, attend school, and participate in a social life. Today, many Down syndrome adults live semi-independently in group homes, holding down jobs and taking part in their communities. Some Down syndrome adults marry.

Cerebral Palsy

What is cerebral palsy?
Cerebral palsy is the term used to describe conditions that affect the control of movement and posture. It is caused by damage to the part of the brain that controls muscle movement. Symptoms range from mild to severe, but the condition tends not to worsen as the child gets older. Physical therapies and other treatments can significantly improve the condition. Many children with cerebral palsy also have other medical conditions, such as metal retardation, learning disabilities, or problems with vision, hearing, or speech.

How common is cerebral palsy?
Cerebral palsy is generally not diagnosed until the child has reached age 2 or 3. Approximately two children out of 1, 000 over the age of 3 have cerebral palsy. Currently in the United States, about 500,000 individuals — both children and adults — are diagnosed with cerebral palsy. Scientists do not know exactly what causes cerebral palsy, but recent research has shed some light on the topic. In about 70 percent of all cases, the damage to the brain takes place before birth. In a small number of cases, cerebral palsy is caused during delivery or in the first months of life. Rh disease, as well as certain infections during pregnancy, such as rubella and toxoplasmosis, are known to increase the risk of brain damage to the fetus. Brain damage can also occur when the placenta is not functioning properly. Premature babies who weigh less than 3 1/3 pounds are up to 30 times more likely to develop cerebral palsy than full-term babies. Doctors used to believe that a lack of oxygen during difficult deliveries was a primary cause of cerebral palsy, but recent studies suggest that only about 10 percent of cases fall into this category.

How is the child affected by cerebral palsy?
Parents may become concerned when a child has trouble reaching physical milestones. A child with cerebral palsy may have trouble rolling over, sitting, walking, and crawling. Some children have low muscle tone and appear floppy; others have increased muscle tone, which makes them appear stiff. There are three major types of cerebral palsy. About 70 percent of CP cases are categorized as spastic cerebral palsy, in which muscles are stiff, making movements and walking difficult. Dyskinetic cerebral palsy affects 10 to 20 percent of CP patients. It is characterized by fluctuations in muscle tone. Children with this form of CP may have trouble sitting or swallowing. Ataxic cerebral palsy is the least common form; it affects balance and coordination. A person with this type of CP may walk with an unsteady gait and have difficulty with fine motor tasks.

What are the treatments for cerebral palsy?
While there is no cure for cerebral palsy, with treatment and physical therapy most children can significantly improve over time. Physical therapy often begins soon after diagnosis, helping a child improve motor skills such as sitting and walking. There are drug therapies and surgical procedures for some types of CP. Many children work with a speech therapist to improve their communication skills, and with an occupational therapist to manage the skills of daily living.

Genital and Urinary Tract Defects

What are genital or urinary tract defects?
Birth defects of the genitals or urinary tract can involve the kidneys, ureters, bladder, urethra, and male and female genitals. For boys, the genitals include the penis, prostate gland, and testes. For girls, they include the vagina, uterus, fallopian tubes, and ovaries. Some of the most common defects include renal agenesis, hydronephrosis, hypospadias, and ambiguous genitals.

How common are genital or urinary tract defects?
Abnormalities of the genitals and urinary tract are among the most common of all birth defects, present in as many as one in 10 babies. Some abnormalities are minor and produce no symptoms. Other malformations can be more serious, causing urinary tract infections, pain, or kidney damage. Many urinary tract defects can be diagnosed at birth with an ultrasound. The causes of most urinary and genital birth defects are unknown, but some abnormalities are inherited from parents who either have the disorder or carry the gene for it.

How is the child affected by genital or urinary tract defects?
The symptoms of urinary and genital birth defects vary. Often children born with this kind of defect are prone to urinary tract infections, high blood pressure, and other problems. A baby born with a single kidney (unilateral renal agenesis) may be at increased risk for high blood pressure, kidney stones, or kidney failure. Hydronephrosis, caused by a blockage in the urinary tract, can cause kidney failure. Children with bladder extrophy or epispadias may have bladder-control problems. A child born with ambiguous genitals may suffer significant psychological stress. Many genital and urinary tract defects can be painful.

What are the treatments for genital or urinary tract defects?
There are many successful surgical options to treat birth defects involving the genitals and urinary tract. In fact, some surgeries can be performed even before the baby is born. For example, significant hydronephrosis is diagnosed in about one in 500 pregnancies during a prenatal ultrasound examination. Sometimes, doctors will opt to insert a small tube into the fetus's bladder to reduce the kidney swelling. Prenatal treatment of these kinds of obstructions has been the most successful form of fetal surgery to date. Other surgeries are available to affected babies, in infancy or early childhood, to correct the different kinds of defects. Some children require multiple surgeries to achieve normal urinary and genital function. Sometimes, as in the case of ambiguous genitals, psychological counseling is recommended in addition to surgical intervention.

Spina Bifida

What is spina bifida?
Spina bifida is the most common of a group of birth defects called neural tube defects. The neural tube is the part of the embryo that eventually develops into the brain and spinal cord. The neural tube forms early in pregnancy, by the 28th day after conception. When something goes wrong in this process and the neural tube does not close properly, the spinal cord and sometimes the vertebrae do not develop normally. The backbone and spinal cord can be affected.

How common is spina bifida?
Spina bifida is one of the most common severe birth defects, affecting approximately one in 2,000 babies. Spina bifida is usually an isolated birth defect. Almost all babies born with spina bifida and other neural tube defects are born to parents with no family history of these problems. Still, scientists to believe there are both genetic and environmental factors at work. Spina bifida occurs more frequently among Hispanics and whites of European descent; it is less common among African-Americans and Asians. Women with certain chronic health conditions, including diabetes and seizure disorders, have an increased risk of having a baby with spina bifida.

How is the child affected by spina bifida?
There are three forms of spina bifida, each producing different symptoms. The first is occulta — this form is usually without symptoms. It presents as a small gap in the vertebrae, but the spinal cord and nerves are normal and these children generally have no related problems. The second form is meningocele. This is the rarest form and shows as a cyst or a lump poking through the open part of the spine. It can be corrected with surgery. The final form is myelomeningocele. This is the most severe form. A cyst may affect the spinal canal, spinal cord, and nerve roots. Or there may be no cyst, just an exposed section of the spinal cord. There is a high risk of infection, and even after surgery to close the open section, leg paralysis and bladder and bowel control problems remain. Many children will require a wheelchair.

What are the treatments for spina bifida?
Depending on the type of spina bifida in question, treatments range from none to multiple surgeries. A baby with the most severe form of spina bifida will usually require surgery within 48 hours of birth. Soon after surgery, physical therapy is recommended. There are prenatal approaches to the birth defect as well. Studies show that up to 70 percent of neural tube defects, including spina bifida, could be prevented if pregnant women consumed adequate amounts of folic acid, especially in the earliest stages of pregnancy. Folic acid is found in many foods such as orange juice and beans and is also available in most multivitamins. Spina bifida can often be detected through prenatal testing, such as blood tests, ultrasound, and amniocentesis. Prenatal surgery to repair spina bifida birth defects is in the experimental phase.

Congenital HIV Infection

What is congenital HIV infection?
Congenital infections are one of the three major categories of birth defects. The best known in this category is rubella (German measles). However thanks to widespread vaccination programs, rubella is rare in this country. Viral infections and sexually transmitted infections such as HIV are still present in the United States and can endanger a developing fetus. HIV is the virus that causes AIDS. About one baby in 2,700 born in the United States has congenital HIV infection.

How is the child affected by congenital HIV infection?
HIV-infected babies may appear normal at birth, but as many as 20 percent will develop AIDS in the first year of life. Many more will show symptoms by age 6. A person with AIDS can't fight disease normally and is highly susceptible to infections and certain cancers. A child with AIDS is especially at risk for serious illnesses from common bacteria because the virus weakens the immune system. These problems can be life threatening or fatal. Many children who develop AIDS in the first year of life die before age 4.

What treatments are available for congenital HIV infection?
In recent years, much has been learned about the treatment and prevention of HIV infection, particularly for pregnant women. A recent study showed that drug treatment during pregnancy can greatly reduce the risk that an HIV-infected mother will pass the virus on to her child. In addition to drug therapy, other steps can be taken. A woman with HIV may reduce the risk of infecting her baby by opting for a cesarean birth, before natural labor begins and her membranes have ruptured. Also, if a woman and her doctor are aware of her HIV status during pregnancy, certain precautions can be taken during prenatal care to reduce the risk of the infection being transmitted to the baby. The doctor may avoid certain procedures that would increase exposure of the fetus to the mother's blood, such as amniocentesis. The Centers for Disease Control (CDC) recommends that a baby born to an HIV-infected mother be treated with certain drugs in the early weeks of life as a precaution against life-threatening, opportunistic infections.

Fetal Alcohol Syndrome

What is fetal alcohol syndrome?
Fetal alcohol syndrome is one of the most common known causes of mental retardation, and it's the only one that is entirely preventable. FAS is a group of mental and physical birth defects that occur because of excessive consumption of alcohol by the mother during pregnancy. These women either drink excessively throughout pregnancy or have episodes of binge drinking during pregnancy. When a pregnant woman drinks alcohol, it travels through the placenta to her fetus. A developing fetus takes much longer to break down alcohol and as a result, the alcohol level in a fetus's blood can be higher and remain elevated longer, heightening the exposure of the fetus to alcoholic effects. This can cause the baby to suffer lifelong damage.

How common is fetal alcohol syndrome?
Every year in the United States, as many as 2,000 to 12,000 babies are born with fetal alcohol syndrome. As many as 10 times that number are born with what doctors call fetal alcohol exposure, a less-severe condition. FAS occurs in 40 percent of women who are alcoholics or chronic alcohol abusers. Fetal alcohol exposure can occur in the children of women who drink moderately or lightly during pregnancy.

How is the child affected by fetal alcohol syndrome?
Children born with fetal alcohol syndrome are abnormally small at birth. They may have small eyes and an upturned nose. The heart may not have formed properly, and many children with this birth defect have a small or abnormally formed brain. Most have some degree of mental retardation. Many also exhibit difficulties with learning, attention span, coordination, and behavior. The effects of FAS last a lifetime. Adults with FAS often find it difficult to live independently and hold down a job. They may require treatment and supervision for psychological and behavioral problems.

What are the treatments for fetal alcohol syndrome?
The primary focus of fetal alcohol syndrome treatment has been to educate women about the dangers of drinking alcohol during pregnancy. Although many women know that heavy drinking can cause birth defects, many don't realize that even light or moderate drinking can have effects on a developing fetus. In fact, no amount of alcohol consumption has been proven safe, according to the March of Dimes, a nonprofit health agency dedicated to the study and reduction of birth defects. Children born with FAS may require psychological and behavioral counseling, special education to cope with their learning disabilities, and medical treatments throughout their lives.

Source: March of Dimes

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Content courtesy of American Baby.