Facts about Upper and Lower Limb Reduction Defects
Upper and lower limb reduction defects occur when a part of or the entire arm (upper limb) or leg (lower limb) of a fetus fails to form completely during pregnancy. The defect is referred to as a “limb reduction” because a limb is reduced from its normal size or is missing.
How often does limb reduction defects occur?
CDC estimates that each year about 1,500 babies in the United States are born with upper limb reductions and about 750 are born with lower limb reductions.1 In other words, each year about 4 out of every 10,000 babies will have upper limb reductions and about 2 out of every 10,000 babies will have lower limb reductions. Some of these babies will have both upper and lower limb reduction defects.
What problems do children with limb reduction defects have?
Babies and children with limb reduction defects will face various issues and difficulties, but the extent of these will depend on the location and size of the reduction. Some potential difficulties and problems include:
- Difficulties with normal development such as motor skills
- Needing assistance with daily activities such as self-care
- Limitations with certain movements, sports, or activities
- Potential emotional and social issues because of physical appearance
Specific treatment for limb reduction defects will be determined by the child’s doctor, based on things like the child’s age, the extent and type of defect, and the child’s tolerance for certain medications, procedures, and therapies.
The overall goal for treatment of limb reduction defects is to provide the child with a limb that has proper function and appearance. Treatment can vary for each child. Potential treatments include:
- Prosthetics (artificial limbs)
- Orthotics (splints or braces)
- Rehabilitation (physical or occupational therapy)
It is important to remember that some babies and children with limb reductions will have some difficulties and limitations throughout life, but with proper treatment and care they can live long, healthy, and productive lives.
What causes limb reduction defects?
The cause of limb reduction defects is unknown. However, research has shown that certain behaviors or exposures during pregnancy can increase the risk of having a baby with a limb reduction defect. These include:
- Exposure of the mother to certain chemicals or viruses while she is pregnant
- Exposure of the mother to certain medications
- Possible exposure of the mother to tobacco smoking (although more research is needed)
CDC works with many researchers to study risk factors that can increase the chance of having a baby with limb reduction defects, as well as outcomes of babies with the defect. Following are examples of what this research has found:
- A woman taking multivitamins before she gets pregnant might decrease her risk for having a baby with limb reduction defects, although more research is needed.2
- Certain sets of limb reduction defects might be associated with other birth defects, such as heart defects, omphalocele, and gastroschisis.3
Can limb reduction defects be prevented?
There is no known way to prevent this type of defect, but some of the problems experienced later in life by a person born with a limb reduction defect can be prevented if the defect is treated early.
Even so, mothers can take steps before and during pregnancy to have a healthy pregnancy. Steps include taking a daily multivitamin with folic acid (400 micrograms), not smoking, and not drinking alcohol during pregnancy.
- Parker SE, Mai CT, Canfield MA, Rickard R, Wang Y, Meyer RE, Anderson P, Mason CA, Collins JS, Kirby RS, Correa A. Updated national birth prevalence estimates for selected birth defects in the United States, 2004–2006. Birth Defects Res A.2010;88(12):1008-16.
- Yang QH, Khoury MJ, Olney RS, & Mulinare J. Does periconceptional multivitamin use reduce the risk for limb deficiency in offspring? Epidemiology. 1997;8: 157-61.
- Rosano A, Botto LD, Olney RS, Khoury MJ, Ritvanen A, Goujard J, et al. Limb defects associated with major congenital anomalies: clinical and epidemiological study from the International Clearinghouse for birth defects monitoring systems. Am J Med Genet. 2000;93: 110-16.