Study of isolated apparent amniogenic limb deficiency in Hungary, 1975-1984.

A population-based and validated data set of 206 cases with apparent amniogenic limb deficiency was ascertained in Hungary between 1975 and 1984. Such limb defects frequently (36%) associated with nonlimb abnormalities. In 134 cases with isolated defects typically more limbs are affected, upper and lower limbs, right and left sides, and both sexes are equally affected. Case-control analysis of such isolated cases indicates a lower socioeconomic status of parents, a higher parity, more frequent unwanted pregnancies, preterm birth, and a higher rate of threatened abortion. Familial occurrence was not found in 415 first-degree relatives.