Phocomelia, congenital malformation

Phocomelia is a congenital defect centered on the absence of an arm, leg or multiple limbs. Sometimes a heart defect also occurs. Phocomelia is very rare and occurs in an average of 4 to 8 people in the Netherlands. Phocomelia is often confused with amputation of a limb. However, an amputation is not congenital, phocomelia is. How does this actually arise and what is the future for someone with this abnormality?

What is phocomelia?

Phocomelia is also called the seal deformity or seal limb. It is a congenital defect or deformity in which arms or legs are missing. This can be all four limbs, but also three, two or one limb. The hands or feet are developed or partially developed and are attached directly to the shoulder or hip. Phocomelia also means the absence of part of the limbs, such as only the forearms or lower legs.

Rare anomaly

The congenital defect is rare. It is so rare that it is an unknown abnormality in many people. People who do have it are often associated with an accident in which the arm(s) or leg is lost. In the 1950s and 1960s, phocomelia became more common due to the use of the drug thalidomide during pregnancy. It was supposed to prevent pregnancy vomiting, especially morning sickness. In 1961 the drug was withdrawn from the market due to its serious effects on babies.


Babies born with phocolemia do not have an arm or legs or multiple limbs. Sometimes part of the leg or arm is missing. The hands and feet or part of them are attached directly to the shoulder or hip or to the stump of the arm or leg. Sometimes the child has multiple abnormalities or an underlying disease. Heart defects are more common in children with phocomelia.

Future and treatment

Most children can live well with their abnormality. They are not better accustomed and do not miss the missing limb. Sometimes additional aids are needed, especially when several limbs are missing. As a result, the child and later adults may encounter limitations. Heart defects must be treated to prevent heart failure. An underlying disease such as Cornelia de Lange syndrome can be treated with a focus on reducing the symptoms. A prosthesis on the leg or legs ensures that the child learns to walk. It often takes longer than usual for the child to learn to walk properly. It is also slower at learning certain skills. Sport is not impossible but sometimes has its limitations, depending on the type of sport. Certain professions cannot be practiced due to the lack of employment, especially among the poor.

Preventing phocomelia

The phocomelia disorder can be prevented in certain cases. During pregnancy it is important to avoid medications that can cause birth defects. These medications are called teratogenic. This means that the drug is capable of causing serious congenital and physical abnormalities in the child. Examples are the aforementioned thalidomide or chemotherapy. In addition, certain infectious diseases can seriously damage the unborn baby. Rubella is a well-known example of this. Sometimes no cause is found and there is probably a construction error during the first three months of pregnancy. Phocomelia does not always have to develop when harmful medications are used during pregnancy. This depends on the period in the pregnancy. During the first three months the baby is largely formed and developed. If a harmful substance is introduced during this period, the risk of deviations is greatest. This also depends on the placenta and its permeability. Not every substance passes through the placenta and ends up in the baby.
The greatest danger is the new medicines that have been tested on animals and humans but not yet on pregnant women. Animal testing has not shown that these new medications cause birth defects, but whether this is also the case in humans is unknown. This often concerns medicines that have been on the market for less than ten years. Only then can it be determined with certainty whether these medications pose a danger to the unborn baby. If a pregnant woman needs medication during pregnancy, it is better to ask the doctor to prescribe medication that is known to be harmless to the baby.

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