Delivery Characteristics and the Risk of Early-Onset Neonatal Sepsis

Abstract

Background and objectives: Multiple strategies are used to identify newborn infants at high risk of culture-confirmed early-onset sepsis (EOS). Delivery characteristics have been used to identify preterm infants at lowest risk of infection to guide initiation of empirical antibiotics. Our objectives were to identify term and preterm infants at lowest risk of EOS using delivery characteristics and to determine antibiotic use among them.

Methods: This was a retrospective cohort study of term and preterm infants born January 1, 2009 to December 31, 2014, with blood culture with or without cerebrospinal fluid culture obtained ≤72 hours after birth. Criteria for determining low EOS risk included: cesarean delivery, without labor or membrane rupture before delivery, and no antepartum concern for intraamniotic infection or nonreassuring fetal status. We determined the association between these characteristics, incidence of EOS, and antibiotic duration among infants without EOS.

Results: Among 53 575 births, 7549 infants (14.1%) were evaluated and 41 (0.5%) of those evaluated had EOS. Low-risk delivery characteristics were present for 1121 (14.8%) evaluated infants, and none had EOS. Whereas antibiotics were initiated in a lower proportion of these infants (80.4% vs 91.0%, P < .001), duration of antibiotics administered to infants born with and without low-risk characteristics was not different (adjusted difference 0.6 hours, 95% CI [-3.8, 5.1]).

Conclusions: Risk of EOS among infants with low-risk delivery characteristics is extremely low. Despite this, a substantial proportion of these infants are administered antibiotics. Delivery characteristics should inform empirical antibiotic management decisions among infants born at all gestational ages.

FIGURE 1

Algorithmic approach for low-risk delivery characteristics determination. A, ROM ≥0.1 hours and ≤24 hours. B, If ROM <0.1 hours but duration between onset of labor and delivery ≥0.1 hours (6 minutes), then classified as not low-risk. If ROM missing, >24 hours, or implausible (ie, negative number), then classified as not low-risk in the presence of any labor (duration between labor and delivery >0). C, SROM indicated among subjects with ROM negative, missing, or >24 hours. D, Labor and delivery admission reason indicating labor, preterm labor, or ROM. E, Attempt to VBAC or TOLAC. F, PTL and/or PROM indicated; G, cesarean delivery indicating labor, arrest of labor, arrest or failure of descent, secondary arrest of dilation, prolonged labor, failure to progress, failure of induction, failure of vacuum, attempt to VBAC, failure of VBAC, ROM, placental abruption, or cord prolapse. H, Induction of labor indicated; I, Chorioamnionitis present, diagnosed by obstetric provider. J, Intrapartum complication indicating placental abruption, placenta previa with hemorrhage, labor, PROM, chorioamnionitis, or maternal fever. K, Cervical ripening agents (Cervidil, Cytotec, Foley Bulb, or Misoprostol) used indicating trial of vaginal delivery. L, Diagnosis code from delivery encounter indicating labor, PROM, prolonged ROM, placental abruption, chorioamnionitis, maternal fever, or failed induction. M, Chart review only performed for infants with culture-confirmed early-onset sepsis; evaluated for any previous criteria for not low-risk including contractions and nonreassuring fetal status. CSF (cerebrospinal fluid); GA (gestational age); PROM (premature rupture of membranes); PTL (preterm labor); CS (cesarean delivery); ROM (rupture of membranes); SROM (spontaneous rupture of membranes); TOLAC (trial of labor after cesarean delivery); VBAC (vaginal birth after cesarean delivery).