MORBIDITY ASSOCIATED WITH INDUCTION OF LABOR

Abstract

Hamblenl states that we do not know why labor begins. Reynolds2 believes that the onset of labor is due to alterations in estrogen-pituitary-progestin balance influenced by uterine distention. The most helpful work comes from Lyon3 in his search to find changes concurrent with the initiation of labor. By using the new glucuronic acid method, the NaPG excretion in the urine decreases preceding the onset of labor similarly in those cases at term, postmature, and in premature groups. There is a positive correlation between an extensive fall of conjugated pregnandiol and the onset of labor. Also, there is strong evidence of a marked drop in available progesterone preceding the onset of normal labor. With this new knowledge available, a different interpretation may be placed on studies of induced labor. Lyon3 shows there is a 58 per cent decrease of sodium pregnandiol glucuronidate excretion in the urine during the four days before delivery takes place. The greatest changes take place within the 48 hours to 72 hours preceding termination of the third stage of labor. Morton* of Lynch’s Clinic reports induction of labor by means of artificial rupture of the membranes, castor oil and quinine, and nasal pituitrin. Guttmaeher, in 1931, and Slemons,g in 1932, report further on induction of labor by means of artificial rupture of the membranes, showing that the latent period and duration of labor are shorter whenever the cervix is dilated, and naturally effaced at the time the membranes are ruptured artificially for ind.uction of labor. Stern7 Plass,s and Mathieu and Holmang all show the low morbidity and excellent results obtained by induction. It must be remembered, however, that their material was selected from abundance and that their skill and working conditions were of the best.