Problems with using total serum bilirubin as a criterion for phototherapy in extremely low-birthweight infants.

BACKGROUND: Despite the early use of phototherapy and exchange transfusion in premature infants based on total serum bilirubin (TSB), the reemergence of kernicterus has been reported. The aim of this study was to assess the validity of using TSB as the criterion for phototherapy in extremely low-birthweight infants (ELBWI). METHODS: We reviewed the medical charts of 43 ELBWI admitted to hospital between January 2009 and December 2010, and analyzed the relationship between TSB and unbound bilirubin (UB). RESULTS: No infant underwent exchange transfusion or developed acute bilirubin encephalopathy. There was a significant correlation between TSB and UB measured immediately before phototherapy during the first 7 days of life (r = 0.657, P < 0.001), but none thereafter (r = 0.120, P = 0.213). Thirty-seven percent of infants who underwent phototherapy during the first 7 days of life had suprathreshold USB but subthreshold TSB, whereas this rose to 97% thereafter. CONCLUSIONS: No correlation was observed between TSB and UB in ELBWI after the first 7 days of life, and almost all phototherapy sessions were initiated based on the UB criterion, even though TSB was below the accepted threshold. UB may be high if jaundice is evaluated solely on the basis of TSB.

Comparison of neurodevelopmental outcomes between monochorionic and dichorionic twins with birth weight ≤ 1500 g in Japan: a register-based cohort study.

OBJECTIVE: To examine the relationship between chorionicity and neurodevelopmental outcomes in very low birth weight twins at 3 years of age. STUDY DESIGN: A retrospective cohort study of 3538 twins who were admitted to 91 tertiary perinatal centers in the Neonatal Research Network of Japan between 2003 and 2012. RESULTS: In a comparison of the followed-up 796 monochorionic twins and 786 dichorionic twins, the overall rate of neurodevelopmental impairment was higher in monochorionic twins; specifically, the rate of disability in the language-social area of the Japanese standardized developmental test was higher in monochorionic twins than in dichorionic twins (adjusted odds ratio, 1.55; 95% confidence interval, 1.07-2.25; P = 0.02). CONCLUSIONS: Chorionicity was associated with neurodevelopmental outcome (especially for language and social development) in a large cohort of very low birth weight twins who had a high rate of perinatal morbidity and neurodevelopmental impairment.

Perinatal Factors Affecting Serum Hepcidin Levels in Low-Birth-Weight Infants.

BACKGROUND: Hepcidin, an iron-regulatory hormone, plays a key role in preventing iron overload. Few studies have investigated the regulation of hepcidin in low-birth-weight (LBW) infants who are vulnerable to iron imbalance. OBJECTIVES: To identify perinatal factors associated with serum hepcidin levels in LBW infants. METHODS: Ninety-two LBW infants with a median gestational age (GA) of 32.6 weeks and birth weight of 1,587 g were prospectively enrolled. Serum hepcidin-25 (Hep25) levels were measured from umbilical cord blood using liquid chromatography-tandem mass spectrometry. The relationship between Hep25 levels and prematurity or other possible hepcidin-regulatory factors was evaluated. RESULTS: The median Hep25 level was 7.3 ng/mL (interquartile range: 2.85-16.38). log(Hep25) correlated with birth weight (r = 0.229, p = 0.028), log(interleukin-6 [IL-6]) (r = 0.408, p < 0.001), log(erythropoietin) (r = -0.302, p = 0.004), transferrin saturation (r = 0.29, p = 0.005), soluble transferrin receptor (r = -0.500, p < 0.001), and log(ferritin) (r = 0.696, p < 0.001). Serum iron and hemoglobin levels did not correlate with log(Hep25). Hep25 levels were higher among infants with chorioamnionitis and infants born vaginally and lower among infants born to mothers with pregnancy-induced hypertension than among infants without the respective characteristics. Stepwise multiple linear regression analysis confirmed the significant association of log(Hep25) with GA, log(IL-6), log(erythropoietin), and soluble transferrin receptor. CONCLUSIONS: Among LBW infants, GA, IL-6, erythropoietin, and soluble transferrin receptor were associated with Hep25 levels. Therefore, prematurity, inflammation, hypoxia, and erythropoietic activity may be important perinatal factors that affect hepcidin levels.