Babies with thumb hypoplasia are born with a thumb that is smaller than normal,
or with the thumb missing completely. Sometimes the bones of the wrist or arm are
smaller or missing too. Thumb hypoplasia can happen on one or both hands.
What Causes Thumb Hypoplasia?
Thumb hypoplasia (also called hypoplastic thumb) happens before
a baby is born. When a baby's hands are first forming, they are shaped like mittens.
Then the fingers and thumb develop. In babies with thumb hypoplasia, the thumb does
not form completely. Thumb hypoplasia is not caused by anything a mother did or did
not do while pregnant.
Who Gets Thumb Hypoplasia?
Any baby can be born with thumb
. Sometimes, it happens as part of a genetic
How Is Thumb Hypoplasia Diagnosed?
A prenatal ultrasound
might show thumb hypoplasia. Otherwise, doctors diagnose it when a baby is born.
the bones in the thumbs and hands will help the surgeon decide on the best kind of
treatment. Other tests might be done to see if the thumb hypoplasia is part of a genetic
How Is Thumb Hypoplasia Treated?
The thumb is a very important part of the hand. Surgery is usually recommended
to improve a small or weak thumb. If the thumb is missing, the index finger can be
made into a new thumb (this is called