RESUMO
OBJECTIVE: This study evaluates whether unbound bilirubin is a better predictor of auditory neuropathy spectrum disorder (ANSD) than total serum bilirubin (TSB) or the bilirubin:albumin molar ratio (BAMR) in late preterm and term neonates with severe jaundice (TSB ≥20 mg/dL or TSB that met exchange transfusion criteria). STUDY DESIGN: Infants ≥34 weeks' gestation with severe jaundice during the first 2 weeks of life were eligible for the prospective observational study. A comprehensive auditory evaluation was performed within 72 hours of peak TSB. ANSD was defined as absent or abnormal auditory brainstem evoked response waveform morphology at 80-decibel click intensity in the presence of normal outer hair cell function. TSB, serum albumin, and unbound bilirubin were measured using the colorimetric, bromocresol green, and modified peroxidase method, respectively. RESULTS: Five of 44 infants developed ANSD. By logistic regression, peak unbound bilirubin but not peak TSB or peak BAMR was associated with ANSD (OR, 4.6; 95% CI, 1.6-13.5; P = .002). On comparing receiver operating characteristic curves, the area under the curve for unbound bilirubin (0.92) was significantly greater (P = .04) compared with the area under the curve for TSB (0.50) or BAMR (0.62). CONCLUSIONS: Unbound bilirubin is a more sensitive and specific predictor of ANSD than TSB or BAMR in late preterm and term infants with severe jaundice.
Assuntos
Bilirrubina/sangue , Perda Auditiva Central/diagnóstico , Recém-Nascido Prematuro , Icterícia Neonatal/sangue , Icterícia Neonatal/complicações , Audiometria , Biomarcadores/sangue , Potenciais Evocados Auditivos do Tronco Encefálico , Feminino , Perda Auditiva Central/complicações , Humanos , Recém-Nascido , Masculino , Estudos Prospectivos , Sensibilidade e Especificidade , Albumina Sérica/análise , Nascimento a TermoRESUMO
OBJECTIVE: To determine whether cord serum ferritin level is associated with auditory brainstem evoked response interpeak latencies, an index of auditory neural myelination, in infants at ≥ 35 weeks gestational age (GA). STUDY DESIGN: This prospective study compared auditory neural myelination in infants with latent iron deficiency (cord serum ferritin, 11-75 ng/mL) and infants with normal iron status (cord serum ferritin, >75 ng/mL) at birth. Our inclusion criteria were infants born at ≥ 35 weeks GA who had cord blood collected soon after birth and had 1 or more of the following risk factors for poor in utero iron status: maternal diabetes mellitus, pregnancy-induced hypertension, and intrauterine growth restriction. Cord serum ferritin level was measured using the chemiluminescence immunoassay method. Auditory brainstem evoked response was measured using 80-dB normal hearing level click stimuli at a rate of 69.9/second within 48 hours after birth to evaluate interpeak latencies, a measure of nerve conduction velocity or myelination. RESULTS: Of the 45 infants studied, 12 had latent iron deficiency. On repeated-measures ANCOVA using interpeak latencies I-III, III-V, and I-V as multiple outcomes, infants with latent iron deficiency had significantly prolonged interpeak latencies (P = .01) compared with infants with normal iron status after controlling for confounders. CONCLUSION: In utero latent iron deficiency is associated with abnormal auditory neural myelination at birth in infants born at ≥ 35 weeks GA.
Assuntos
Anemia Ferropriva/complicações , Anemia Ferropriva/diagnóstico , Nervo Coclear/patologia , Ferritinas/sangue , Sangue Fetal/química , Bainha de Mielina/metabolismo , Análise de Variância , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Humanos , Imunoensaio , Recém-Nascido , Masculino , Gravidez , Estudos Prospectivos , Fatores de RiscoRESUMO
OBJECTIVE: To determine whether cord ferritin (CF) concentration, an index of in utero iron status, is associated with auditory neural maturation in premature infants. STUDY DESIGN: A prospective cohort study was performed to compare auditory neural maturation in infants with latent iron deficiency (CF 11-75 ng/mL) and infants with normal iron status (CF > 75 ng/mL) at birth. Our inclusion criteria were infants of 27-33 weeks gestational age who were admitted to the neonatal intensive care unit between July 2007 and November 2008 within 12 hours after birth and had cord blood collected. Infants with TORCH infections (toxoplasmosis, other infections, rubella, cytomegalovirus infection, and herpes simplex), chromosomal disorders, craniofacial anomalies, culture-proven sepsis, and/or unstable conditions were excluded. CF level was measured using a chemiluminescence immunoassay method. Bilateral monaural auditory brainstem evoked response (ABR) was assessed using 80-dB nHL click stimuli at a repetition rate of 29.9/seconds within 48 hours after birth. RESULTS: Of the 80 infants studied, 35 had latent iron deficiency. After controlling for confounders, the infants with latent iron deficiency had significantly prolonged absolute wave latencies I, III, and V and decreased frequency of mature ABR waveforms compared with the infants with normal iron status. CONCLUSION: Premature infants with in utero latent iron deficiency have abnormal auditory neural maturation compared with infants with normal in utero iron status.