Chorioamnionitis is associated with prolonged labor, and some clinicians have suggested that this maternal intrapartum infection itself contributes to abnormal uterine activity. Satin and coworkers (1992) studied the efects of chorioamnionitis on oxytocin stimulation in 266 pregnancies. Infection diagnosed late in labor was found to be a marker of cesarean delivery performed for dystocia. Specifically, 40 percent of women developing chorioamnionitis after requiring oxytocin for dysfunctional labor later required cesarean delivery for dystocia. However, this was not a marker in women diagnosed as having chorioamnionitis early in labor. It is likely that uterine infection in this clinical setting is a consequence of dysfunctional, prolonged labor rather than a cause of dystocia.
Membrane rupture at term without spontaneous uterine contractions complicates approximately 8 percent of pregnancies. In the past, labor stimulation was initiated if contractions did not begin ater 6 to 12 hours. Practice-changing research included that of Hannah (1996) and Peleg (1999) and their associates, who enrolled a total of 5042 pregnancies with ruptured membranes in a randomized investigation. hey measured the efects of induction versus expectant management and also compared induction using intravenous oxytocin with that using prostaglandin E2 gel. There were approximately 1200 pregnancies in each of the four study arms. They concluded that labor induction with intravenous oxtocin was preferred management. This was based on signiicantly fewer intrapartum and postpartum infections in women whose labor was induced. There were no significant differences in cesarean delivery rates. Subsequent analysis by Hannah and coworkers (2000) indicated higher rates of adverse outcomes when expectant management at home was compared with in-hospital observation. Mozurkewich and associates (2009) reported lower rates of chorioamnionitis, metritis, and neonatal intensive care unit admissions for women with term ruptured membranes whose labors were induced compared with those managed expectantly. At Parkland Hospital, labor is induced soon ater admission when ruptured membranes are conirmed at term. In those with hypotonic contractions or with advanced cervical dilation, oxytocin is selected to lower potential hyperstimulation risk. In those with an unfavorable cervix and no or few contraction, prostaglandin E1 (misoprostol) is chosen to promote cervical ripening and contractions. he benefit of prophylactic antibiotics in women with ruptured membranes before labor at term is unclear (Passos, 2012). However, in those with membranes ruptured longer than 18 hours, antibiotics are instituted for group B streptococcal infection prophylaxis (Chap. 64, p. 1221).
Labor can be too slow, but it also can be abnormally rapid. Precipitous labor and delivery is extremely rapid labor and delivery. It may result from an abnormally low resistance of the soft parts of the birth canal, from abnormally strong uterine and abdominal contractions, or rarely from the absence of painful sensations and thus a lack of awareness of vigorous labor.
Precipitous labor terminates in expulsion of the fetus in less than 3 hours. Using this deinition, 25,260 live births-3 percent-were complicated by precipitous labor in the United States in 2013 (Martin, 2015). Despite this incidence, little published information describes maternal and perinatal outcomes.