Diagnostic accuracy of S100B urinary testing at birth in full-term asphyxiated newborns to predict neonatal death.

BACKGROUND: Neonatal death in full-term infants who suffer from perinatal asphyxia (PA) is a major subject of investigation, since few tools exist to predict patients at risk of ominous outcome. We studied the possibility that urine S100B measurement may identify which PA-affected infants are at risk of early postnatal death. METHODOLOGY/PRINCIPAL FINDINGS: In a cross-sectional study between January 1, 2001 and December 1, 2006 we measured S100B protein in urine collected from term infants (n = 132), 60 of whom suffered PA. According to their outcome at 7 days, infants with PA were subsequently classified either as asphyxiated infants complicated by hypoxic ischemic encephalopathy with no ominous outcome (HIE Group; n = 48), or as newborns who died within the first post-natal week (Ominous Outcome Group; n = 12). Routine laboratory variables, cerebral ultrasound, neurological patterns and urine concentrations of S100B protein were determined at first urination and after 24, 48 and 96 hours. The severity of illness in the first 24 hours after birth was measured using the Score for Neonatal Acute Physiology-Perinatal Extension (SNAP-PE). Urine S100B levels were higher from the first urination in the ominous outcome group than in healthy or HIE Groups (p<0.001 for all), and progressively increased. Multiple logistic regression analysis showed a significant correlation between S100B concentrations and the occurrence of neonatal death. At a cut-off >1.0 microg/L S100B had a sensitivity/specificity of 100% for predicting neonatal death. CONCLUSIONS/SIGNIFICANCE: Increased S100B protein urine levels in term newborns suffering PA seem to suggest a higher risk of neonatal death for these infants.

High maternal blood S100B concentrations in pregnancies complicated by intrauterine growth restriction and intraventricular hemorrhage.

BACKGROUND: Intrauterine growth restriction (IUGR) is associated with perinatal mortality and with neurologic damage from intraventricular hemorrhage (IVH). We investigated whether S100B, a neural protein found in high concentrations after cell injury in the nervous system, is increased in serum of women whose pregnancies are complicated by IUGR and whose newborns develop IVH. We also explored the prognostic accuracy of maternal serum S100B for IVH in the newborn. METHODS: We conducted a case-control study of 106 pregnancies complicated by IUGR, including a subgroup (n = 26) who developed IVH after birth, and 212 unaffected pregnancies matched for gestational age. Ultrasound examination, Doppler velocimetry patterns (in the utero-placental vessels and middle cerebral artery), and maternal blood collection were performed before birth; cerebral ultrasound and neurologic examinations were performed after birth. RESULTS: S100B was higher (P <0.001) in IUGR pregnancies complicated by IVH than in those that were not and in controls. At a cutoff of 0.72 microg/L, sensitivity was 100% [95% confidence interval (95% CI), 87%-100%] and specificity was 99.3% (97.5%-99.9%) for prediction of IVH (area under the ROC curve, 0.999). The prevalence of IVH was 8.2% in the whole study population, 93% (95% CI, 83.6%-100%) in those with maternal S100B >0.72 microg/L, and 0% (0%-2.5%) in those with maternal S100B <0.72 microg/L. CONCLUSION: For prediction of IVH, measurements of maternal S100B may be useful at times before clinical, laboratory, and ultrasound patterns can identify risk of IVH.