Umbilical Cord Prolapse in Current Obstetric Practice

Abstract

A prolapsed umbilical cord is an event that can transform a normal labor and delivery into a very problematic state. Reports suggest perinatal mortality rates up to 50%, but in the investigators' experience, this figure seems much too high. It also is uncertain whether, as is traditionally taught, prolapse is most often associated with nonvertex presentation or preterm gestation. This retrospective chart review, undertaken at both a community hospital and a tertiary referral center, covered the years 1995 through 2000. Umbilical cord prolapse, defined as descent of the cord in advance of the presenting part of the fetus, was identified in 51 pregnancies, one being a twin pregnancy with both fetuses affected. The incidence of umbilical cord prolapse in viable singleton pregnancies was 1.6 per 1000. No trend was noted for different physicians or different obstetric practices. Half the women were nulliparous. All but 9 of 52 cases (83%) occurred after 37 weeks gestation. In no case was version or amnioinfusion carried out. One woman with a previous cesarean section had a trial of labor. The rate of umbilical cord prolapse when labor was induced was 2.6 per 1000—representing a 40% to 50% increase over the rate for patients entering labor spontaneously. Multiple gestations occurred at a rate of 36 per 1000. Seven women, 5 of them at less than 34 weeks gestation, had a nonvertex presentation. Fifteen of the 52 cases were considered to be occult when diagnosed at the time of operative delivery done for fetal distress or absence of labor. Only 6 vaginal deliveries were performed. Two previable gestations ended in perinatal deaths. No infant was ill when discharged, and none developed grade III/IV intraventricular hemorrhage. This review points to low fetal mortality and morbidity rates associated with umbilical cord prolapse. It also suggests an association of cord prolapse with induction of labor. It is possible that modern obstetric practices have altered the natural history of umbilical cord prolapse.