Here's a primer on nine of the most common birth defects: their prevalence, causes, symptoms, and treatment.
Understanding Birth Defects
The vast majority of babies born in this country are healthy. But if your child is one of the 3 in 100 infants born with a congenital (acquired after conception) or hereditary birth defect, how can you ensure her long-term health?
While some defects are treatable with drugs or surgery, it's usually your family's efforts to create a positive environment for your child that help minimize the disability.
The first thing you should do if your child is diagnosed with a birth defect is get a second (or more) opinion. Start with your pediatrician or obstetrician, who can refer you to appropriate specialists. In addition to appointments with specialists, you should also keep up with regularly scheduled well-baby visits, because many birth defect complications can be treated through early detection and intervention.
Here are some of the most common birth defects in the U.S. and the impact they may have on your baby and you.
Baby Care Basics: When a Baby Has a Birth Defect
Congenital Heart Defects
An Anatomical Abnormality
Prevalence: Congenital heart defects occur in about 1 in 110 births and have a variety of causes, including genetic abnormalities or a mistake during fetal development. Some may be so mild that they have no visible symptoms.
Detection: In such cases the doctor usually discovers the problem when she detects an abnormal heart sound -- called a murmur -- during a routine examination. Some murmurs are meaningless; further tests are usually required to determine whether your baby's is due to a heart defect.
Serious heart defects are outwardly detectable and, if left untreated, can cause congestive heart failure, in which the heart becomes incapable of pumping enough blood to the lungs or other parts of the body.
- Rapid heartbeat
- Breathing difficulties
- Feeding problems (which result in inadequate weight gain)
- Swelling in the legs, abdomen, or about the eyes
- Pale grey or bluish skin
Treatment: Most heart defects can be corrected or at least improved through surgery, drugs, or a mechanical aid like a pacemaker.
An Anatomical Abnormality
Prevalence: Clubfoot occurs in approximately 1 in 1,000 newborns -- affecting boys about twice as often as girls -- and includes several kinds of ankle and foot deformities. The exact cause of clubfoot isn't clear, but it's probably a combination of heredity and environmental factors that affect fetal growth.
Symptoms: Clubfoot can be mild or severe and can affect one or both feet. Mild clubfoot is not painful and won't bother the baby until he begins to stand or talk.
Treatment: For a mild case, treatment starts immediately after diagnosis and involves gently forcing the foot into the correct position and helping the child do special exercises.
Often, however, the baby needs more drastic treatment, such as plaster casts, bandaging with splints followed by time in special shoes, or surgery followed by exercises. The process may take three to six months, which checkups for several years after.
Cleft Lip or Palate
An Anatomical Abnormality
Prevalence: Cleft lip or palate appears in about 1 in 700 Caucasian babies, more often among Asians and certain groups of Native Americans, and less frequently among African-Americans.
Causes: The exact cause is hard to determine, but it's likely that genetic and environmental factors interact to prevent either the hard palate (the roof of the mouth), the soft palate (the tissue at the back of the mouth), or the upper lip, all of which normally are split early in fetal development, from closing.
Symptoms: The cleft can be mild (a notch on the upper lip) or severe (involving the lip, the floor of the nostril, and the dental arch). A child with a cleft palate usually needs a speech pathologist. Language development can be affected not only by the structure of the lip and palate but also by the side effects of middle-ear infections, which are common in babies and toddlers with this defect (probably because their ears don't drain properly).
Babies with a cleft palate may also need help with feeding. (Those with a cleft lip generally don't have problems in this area.) Because they have trouble sucking, they must be fed in a sitting position with a special bottle. Depending on the severity of the condition, mothers who breastfeed may have to express milk and bottlefeed baby until the cleft is repaired.
Treatment: Surgical repair for a cleft lip should be done by about 3 months of age. Surgery to repair a cleft palate, which restores the partition between the nose and the mouth, is usually done later -- between 6 and 12 months of age -- to allow for some normal growth of the child's face.
Though follow-up treatment is sometimes necessary, repair of a cleft lip or palate almost always leaves the child with only minimal scarring and a face that looks like that of most other children.
An Anatomical Abnormality
Prevalence: Spina bifida occurs in about 1 in 2,000 births, most frequently among Caucasians of European extraction.
Causes: It's caused by a malformation of a neural tube (the embryonic structure that develops into the brain and spine) that prevents the backbone from closing completely during fetal development. Some cases of neural-tube defects can be detected through tests given to the mother during pregnancy. When one is suspected, the baby usually is delivered by cesarean section so specialists can be on hand during and after the birth.
Symptoms: Spina bifida ranges in severity from practically harmless to causing leg paralysis and bladder- and bowel-control problems.
Treatment: In the most severe cases, the baby is operated on within 48 hours of birth (or in-utero through a new technique that is not yet widely available). Parents then learn how to exercise the baby's legs and feet to prepare her for walking with leg braces and crutches. Some children will eventually need to use a wheelchair. The child will also work with specialists in orthopedics and urology.
Adopting a Child with Spina Bifida
Missing or Undeveloped Limbs
An Anatomical Abnormality
Causes: Unfortunately, the cause of this birth defect is largely unknown. Some experts believe that maternal exposure during pregnancy to a chemical or virus that only mildly affects the mother might be possible causes.
Treatment: When a child is born with a limb anomaly, the doctor refers the parents to an orthopedic specialist and a physical therapist. The child is then fitted with a prosthesis (artificial body part) as soon as possible so that he becomes comfortable with it early on.
He will also undergo intensive physical therapy so that he learns to use the prosthesis much as other children learn to control their body parts.
Biochemical Birth Defects
Sometimes certain substances essential to a baby's proper body functioning are either abnormal or completely absent. Without intervention, deficiencies like the following can be devastating (and often even fatal) because they affect many bodily systems.
Prevalence: Sickle-cell disease occurs in around 1 in 625 births, mostly affecting African-Americans and Hispanics of Caribbean ancestry.
Detection: Because of its prevalence, 30 states require that newborns be given the blood test that detects the disorder.
Symptoms: The disease can cause debilitating bouts of pain and damage to vital organs and can sometimes be fatal. Sickle-cell disease affects the hemoglobin (a protein inside the red blood cells) in such a way that the cells become distorted: Instead of their normal, round shape, they look like bananas or sickles (hence the name).
These misformed cells then become trapped in and destroyed by the liver and spleen, resulting in anemia. In severe cases, an affected child may be pale, have shortness of breath, and tire easily. The episodes of pain, called crises, happen when the cells become stuck, blocking tiny blood vessels and cutting off the oxygen supply to various parts of the child's body.
Another complication of sickle-cell disease, noticeable mostly in infants and young children, is vulnerability to severe bacterial infections. Two weapons against this risk are immunization (the usual vaccines, as well as pneumonia and flu shots) and daily preventative penicillin treatments.
Treatment: Although the disease can't be cured, a number of new therapies that reduce the severity and frequency of crises are being studied.
A Biochemical Birth Defect
Prevalence: PKU (phenylketonuria) is an inherited metabolic disorder that occurs in 1 in 15,000 births (less commonly among African-Americans and people of Jewish descent).
Detection: All babies in the U.S. are tested for the disease soon after birth.
Symptoms: A child with PKU is missing a crucial enzyme that breaks down a protein called phenylalanine that is found in many goods. If PKU is left untreated, this protein can rise to high concentrations in the body and cause mental retardation.
Treatment: Children born with PKU can live a normal life if put on a strict diet. Usually started before the fourth week of life, this diet is low in foods that contain phenylalanine, including breast milk and cow's milk. Instead, an affected child must be fed a special formula.
As the baby gets older, however, she can eat certain vegetables, fruits, and grain products but usually must avoid cheese, meat, fish, and eggs. Regular blood tests of phenylalanine levels can help determine what an affected child can and can't eat.
Chromosomal Birth Defects
Two of the most common abnormalities, Down syndrome and Fragile X syndrome, are also frequent causes of mental retardation. Both can be diagnosed before birth. While neither defect is curable, early intervention allows a child to develop to his full potential.
Prevalence: Though Down syndrome occurs in 1 in 800 births overall, the incidence is much higher in older mothers.
Symptoms: A child with Down syndrome generally has characteristic physical features, including slanted eyes; small ears that fold over at the top; a small mouth, which makes the tongue appear larger; a small nose with a flattened nasal bridge; a short neck; and small hands with short fingers.
More than 50 percent of children with this defect have visual or hearing impairments. Ear infections, heart defects, and intestinal malformations are also common among children with this defect.
Though children with Down syndrome have some degree of mental retardation, most can be expected to do many of the same things that any young child can do -- including walking, talking, and being toilet trained -- although generally they learn how to do so later than unaffected children.
Fragile X Syndrome
A Chromosomal Birth Defect
Prevalence: Fragile X syndrome primarily affects males (1 in 1,500). Although 1 in 1,000 females is a carrier, only one in three shows outward signs of having the defect, including intellectual impairment. The range of retardation varies from mild to severe.
Symptoms: The physical characteristics of Fragile X syndrome may include large ears, an elongated face, poor muscle tone, flat feet, large testicles, overcrowded teeth, cleft palate, heart problems, and autistic-like tendencies. Affected children may also suffer seizures.
However, many children with Fragile X syndrome appear to be physically normal at birth, so a diagnosis may not be made until the ages of 18 months and 2 years. At that time, a lack of language development coupled with other developmental delays usually prompts testing.
Treatment: As with Down syndrome, children with Fragile X syndrome can be expected to do most things that any young child can do, although they also generally learn these things later than unaffected children. And, as with most of these birth defects, early-intervention programs begun in infancy can help maximize the child's development.
Fortunately for babies born with birth defects and the parents who care for them, new treatments are being studied every day. Ask questions, learn all you can, and focus on your child's particular impairments so you can do everything possible to help him develop to his full potential.
Richard B. Johnston Jr., MD, FAAP, is a professor of pediatrics and Associate Dean for Research Development at the University of Colorado School of Medicine. He also serves as the Executive Vice President for Academic Affairs at the National Jewish Medical and Research Center, and he is an active consultant to the March of Dimes.
Originally published in American Baby magazine, August 1999. Updated July 2005.
All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.