CHARLESTON, S.C. — The development of chorioamnionitis in patients with preterm premature rupture of membranes is associated with an increased risk for adverse neonatal outcomes, Natali Aziz, M.D., reported at the annual meeting of the Infectious Diseases Society for Obstetrics and Gynecology.
In a retrospective cohort study of 1,153 patients who gave birth between 1980 and 2001 with a diagnosis of preterm premature rupture of membranes (PPROM) made at 24 to 34 weeks' gestation, 29% were diagnosed with chorioamnionitis before delivery. Univariate outcomes on a variety of measures—such as Apgar scores and incidence of respiratory distress syndrome, intracerebral hemorrhage, and pneumonia—were significantly poorer in neonates born to mothers with chorioamnionitis, compared with those born to mothers without chorioamnionitis, said Dr. Aziz of the University of California, San Francisco.
“Management in this setting is better examined prospectively in a randomized, controlled trial, yet given these data, when managing a patient with preterm premature rupture of membranes we must weigh the risks of prematurity against those of expectant management with the ongoing possibility of development of chorioamnionitis,” she said.
Differences were noted in the rates of chorioamnionitis based on gestational age at the time of rupture of membranes (rate of 46% at gestational age of 24–25 weeks vs. 18% at 32 weeks or greater) and duration of latency (higher rates in those with latency greater than 48 hours). Subgroup analyses to adjust for these factors were performed. Many clinical differences remained, but statistical significance was lost due to smaller sample sizes.
In the subgroup analysis based on gestational age at time of rupture of membranes (grouped in 2-week intervals), nonnecrotizing enterocolitis was more common among those with chorioamnionitis in the 24− to 25-week subgroup, intracranial hemorrhage was more common among those with chorioamnionitis in the 30− to 31-week subgroup, and pneumonia was more common among those with chorioamnionitis in the 32-week or greater subgroup.
In a model adjusted for gestational age at the time of ruptured membranes, duration of latency, and use of betamethasone, the chorioamniotic group had significantly higher incidences of intracranial hemorrhage, pneumonia, hyperbilirubinemia, and a neonatal composite variable, including intracranial hemorrhage, pneumonia, and sepsis.