Amniotic Threads

AMNIOTIC THREADS, PERETIAZKI, SRASHCHENIYA (or Simonart's bands), represent one of the very important anomalies of the amnion (see), consisting in the formation of adhesions, bridges between it and various parts of the fetus. A. n. and p. have great significance in the origin of a series of fetal deformities, in some cases such a connection is obvious (e.g., the threads directly contract a deformed member or even amputate it along the line of constriction—the so-called fetal, or spontaneous amputations); in others it is merely more or less probable (see Deformities), all the more so that A. n. and p. in full-term fetuses may be absent in cases of undoubtedly amniogenic deformities. The formation of A. n. and p. refers to early periods of pregnancy, when the amniotic cavity is negligible, and the fetal body fills it almost entirely. It is not clarified whether A. n. and p. occur during the formation of the amniotic cavity itself, or whether they arise subsequently as a product of secondary adhesions of the fetus and amnion, e.g., as a result of amniotitis, i.e., inflammation of the amnion. The majority of authors reject the latter theory and incline toward the idea of improper development of the amnion itself in the sense of insufficient

formation of amniotic fluid (oligohydramnion). Deformities most frequently associated with A. n. and p. cover, mainly, the head and extremities, which is explained by the early formation of the amnion precisely here and the numerous bends, depressions, and clefts in the region of the face and neck, representing the greatest complexity of the formation itself. Sometimes A. n. and p. remain on the fetal body in the form of caudal appendages.