DECREASED PLACENTAL AND UMBILICAL-CORD GLYCOGEN LEVELS ASSOCIATED WITH MECONIUM-STAINED AMNIOTIC-FLUID

Most frequently, placental glycogen has been studied as an index of fe tal nutrition. There are no published studies of placental glycogen as an index of fetal stress. In this study of 1573 samples from 71 place ntae, glycogen levels in the placental disk, fetal membranes and umbil ical cord of normal uncomplicated pregnancies were compared with those in complicated pregnancies. The complicated pregnancies included pret erm delivery, hypertensive disorders, inadequate prenatal care, substa nce abuse, maternal fever or infection, obesity, diabetes mellitus, pr emature rupture of membranes, intrauterine growth retardation, sickle cell trait, and acute meconium staining of amniotic fluid at delivery. The data showed that the only significant differences were in the sub group complicated by meconium-stained amniotic fluid in which the plac ental disks and umbilical cords had significantly lower (P=0.0006) gly cogen levels. This finding suggests a relatively specific association. It is interesting to speculate that the passage of meconium with its vasoconstrictive effect increases utilization of local glycogen stores , decreases local glycogen reserves needed for the work of further vas oconstriction, and, in the event of subsequent acute stress, impairs v ascular perfusion of tissues. In this way, meconium could predispose t he infant to asphyxia. (C) 1998 W. B. Saunders Company Ltd.