Fetal limb deformities due to amniotic constrictions (a possible consequence of preceding amniocentesis)

The nature and origin of circular constrictions and intrauterine amputations can be studied more effectively in the fetus than in the newborn. Two cases of fetal micro- and syndactyly secondary to ring constrictions are discussed with respect to morphological processes. The amniotic membranes display active chorionic proliferation in addition to amniotic rupture and passive string formation. Moreover, association between the origin of amniotic bands and preceding amniocentesis seems to be possible in one case though it is difficult to ascertain.