Smotherman W P, Robinson S R
Department of Psychology, Oregon State University, Corvallis 97331.
Am J Obstet Gynecol. 1987 Oct;157(4 Pt 1):982-6. doi: 10.1016/s0002-9378(87)80100-x.
Transient compression of the umbilical cord has been implicated as a potential cause of unexplained brain damage and/or fetal death. We induced acute fetal hypoxia by compressing the umbilical cord of the fetal rat with a microvascular clamp. Direct observation of fetal behavior immediately after cord compression identified a three-phase behavioral response to acute hypoxia, consisting of an initial suppression in motor activity, a brief period of hyperactivity, and a secondary suppression of movement. All three phases occurred in less than 2 minutes from the onset of hypoxia. The stereotypic hypoxic response of rat fetuses may be adaptive as a means of removing mechanical sources of umbilical cord compression. Among fetuses exposed to alcohol in utero, the response to hypoxia was diminished in intensity and duration. Because of their altered hypoxic response, alcohol-exposed fetuses may therefore be at greater risk from transient cord compression in utero.