Clinical and experimental studies of the congenital constriction band syndrome, with an emphasis on its etiology.

The findings in fifty-nine patients with congenital constriction band syndrome and in experiments in which limb malformations resembling those of the human constriction band syndrome were successfully reproduced in rat fetuses by amniocentesis indicated that these malformations arise from excessive contraction of the uterine muscle during pregnancy, with resulting hemorrhages from the marginal blood sinuses of the digital rays. Such malformations in humans may arise during the fifth and sixth weeks counted from ovulation. It therefore was concluded that this syndrome is not hereditary but is produced by prenatal environmental factors.