Congenital amputation is the absence of a limb or part of a limb at birth.
Description
There are different types of congenital amputation birth defects. An infant with congenital amputation may be missing an entire limb or just a portion of a limb. The complete absence of a limb leaving a stump is called transverse deficiency, or amelia. When a specific part of a limb is missing, for example, when the fibula bone in the lower leg is missing, but the rest of the leg is intact, it is called a longitudinal deficiency. The condition in which only a mid-portion of a limb is missing, as when the hands or feet are attached directly to the trunk, is known as phocomelia.
Congenital amputation may be the result of the constriction of fibrous bands within the membrane that surrounds the developing fetus (amniotic band syndrome), the exposure to substances known to cause birth defects (teratogenic agents), genetic factors, or other, unknown, causes.
Demographics
An estimated one in 2,000 babies is born with all or part of a limb missing. This number includes everything from a missing part of a finger to the absence of both arms and both legs. Congenital amputation is the least common form of amputation. There have been occasional periods in history where the frequency of congenital amputations has increased. For example, in the 1960s many pregnant women were given tranquilizers containing the drug thalidomide. The result was the "thalidomide tragedy" during which there was a drastic increase in the number of babies born with deformations of the limbs. In this case, the birth defect usually presented itself as very small, deformed versions of normal limbs. Subsequently, birth defects as a result of exposure to Agent Orange, the U.S. defoliant used in Vietnam, and radiation exposure near the site of the Chernobyl disaster in Russia have left numerous children with malformed or absent limbs.
Causes and symptoms
Most of the time, the cause of congenital amputations is unknown. According to the March of Dimes, most birth defects have one or more genetic factors and one or more environmental factors, but what the actual factors are in any given case is often difficult, if not impossible, to pinpoint. Most birth defects occur in the first three months of pregnancy when the organs of the fetus are forming.
During the crucial first weeks, frequently before a woman is aware she is pregnant, the developing fetus is most susceptible to substances that can cause birth defects (teratogens). Exposure to teratogens can cause congenital amputation. Congenital amputation can also be caused by genetic factors. In some cases, tight amniotic bands may constrict the developing fetus, preventing a limb from forming properly, if at all. It is estimated that amniotic band syndrome occurs in between one in 12,000 and one in 15,000 live births. It is not known what makes the amniotic bands behave in this way in some instances and not in others.
When to call the doctor
Many congenital amputations are not discovered until the birth of the baby. At that time the doctor overseeing the delivery can give the parents helpful resources and refer them to the appropriate medical professionals to begin to discuss possible treatment paths and to help the parents cope effectively. If the abnormality is discovered before the birth, the obstetrician can help the parents decide what steps should be taken, and parents can begin to plan to meet the special needs their child will have.
Diagnosis
Ultrasound examinations may reveal the absence of a limb in some developing fetuses, but routine ultrasounds may not pick up signs of more subtle defects. However, if a doctor suspects that the fetus is at risk for developing a limb deficiency (for example, if the mother has been exposed to radiation), a more detailed ultrasound examination may be performed.
Treatment
If a problem with amniotic band constriction is detected early enough, it may be possible to correct the bands before there is significant damage to limb development. There have been cases in which physicians have detected amniotic band constriction and performed minimally invasive surgery that freed constricting amniotic bands and preserved the affected limbs. This procedure, however, is not commonly available.
Successful treatment of a child with congenital amputation involves an entire medical team, including a pediatrician, an orthopedist, a psychiatrist or psychologist, a prosthetist (an expert in making artificial limbs, or prosthetics), a social worker, and occupational and physical therapists. There is controversy over whether it is considered sound practice to fit the child early with a functional prosthesis. Some experts believe that this leads to more normal development and less wasting away (atrophy) of the muscles of the limbs. However, some parents and physicians believe that the child should be allowed to learn to play and perform tasks without a prosthesis, if possible. This is thought to help build a child's positive self-image because it does not reinforce the idea that the child is missing something that should be replaced. Also, many children reject prosthetic devices and do not want to wear them. When the child is older, he or she can be involved in decisions concerning whether to be fitted for a prosthesis.
Prognosis
A congenital limb deficiency has a profound effect on the life of the child and his or her parents. Children have been found to be extraordinarily good at learning to accomplish tasks using the means they have available and finding ways to compensate for their disability. Parents can help their child by encouraging persistence, allowing the child to do normal activities for him or herself, and not becoming frustrated and doing them for the child. Occupational therapy can help the child learn to accomplish tasks that are more complex if the child encounters difficulties. Prosthetic devices are increasingly sophisticated. Some experts believe that early fitting of a prosthesis enhances acceptance of the prosthesis by the child and parents.
Prevention
There is no known way to prevent congenital amputations, but the prevention of birth defects in general begins with the well being of the mother before and during pregnancy. Prenatal care should be clear and comprehensive, so that the mother understands both her genetic risks and her environmental risks. Several disciplines in alternative therapy also recommend various supplements and vitamins that may reduce the chances of birth defects. Studies have suggested that a multivitamin including folic acid may reduce birth defects, including congenital abnormalities. Smoking, drinking alcohol, using recreational drugs or drugs not prescribed by a physician and having a poor diet while pregnant may increase the risk of congenital abnormalities. Daily, heavy exposure to chemicals is also thought to be especially dangerous for gestating women.
Parental concerns
Raising a child with one or more congenital amputations can be challenging. The way in which the child thinks of him or herself is dependent on the way in which the parents treat the child and the ways in which the parents introduce the child to others. Parents should be careful to treat the child as they would any other and not to expect any less from him or her. Children with congenital amputations are remarkably good at compensating for their disability. They are not mentally disabled in any way, and less should not be expected from them in an educational setting because of their disability. Lowered expectations can have a detrimental effect on the child's self-image.
Parents also need to be careful about how they respond to questions and comments about their child's disability when their child is present, always keeping in mind that the child can hear their answers and comments. The way in which the parent feels about the child's disability has a very strong impact on how the child feels about it.
KEY TERMS
Prosthetic—Referring to an artificial part of the body.
Prosthetist—A health care professional who is skilled in making and fitting artificial limbs and other prostheses.
Teratogen—Any drug, chemical, maternal disease, or exposure that can cause physical or functional defects in an exposed embryo or fetus.
BOOKS
Klein, Stanley D., and John D. Kemp, eds. Reflections from a Different Journey: What Adults with Disabilities Wish All Parents Knew. New York: McGraw-Hill, 2004.
Smith, Douglas G., Michael, John W. and John H. Bowker, eds. Atlas of Amputations and Limb Deficiencies: Surgical, Prosthetic, and Rehabilitation Principles. Rosemont, IL: American Academy of Orthopedic Surgeons, 2004.
ORGANIZATIONS
March of Dimes Birth Defects Foundation. 1275 Mamaroneck Ave., White Plains, NY 10605. Web site: <www.modimes.org>.
