High levels of unbound bilirubin are associated with acute bilirubin encephalopathy in post-exchange transfusion neonates.

BACKGROUND: Although it is known that unbound bilirubin can enter the brain, there is little evidence of its association with the development of acute bilirubin encephalopathy. Here, we investigated this potential relationship in neonates who had undergone exchange transfusion. METHODS: Data from 46 newborns who underwent exchange transfusion between 2016 and 1-1 to 2018-12-31 at the First People's Hospital of Changde City in China were analyzed. The unbound bilirubin level was taken as the independent variable and the development of the acute bilirubin encephalopathy as the dependent variable. The covariates were age, birth weight, sex, red blood cell count, blood glucose, hemolytic disease, and whether the infant had received phototherapy. RESULTS: The mean age and gestational age of the neonates were 146.5 ± 86.9 h and 38.6 ± 1.3 weeks [38.7(34.6-41.1) weeks] old, respectively; 52.17% were male. Binary logistic regression analysis after adjustment for covariates showed a positive association between the levels of unbound bilirubin and the development of acute bilirubin encephalopathy (odds ratio = 1.41, 95% confidence intervals 1.05-1.91, P = < 0.05). CONCLUSION: There is a significant association between unbound bilirubin levels and the development of acute bilirubin encephalopathy in neonates. Further investigations are required to explore the mechanisms.

G6PD Deficiency Prevalence as a Cause of Neonatal Jaundice in a Neonatal Ward in Dohuk, Iraq.

OBJECTIVE: The current study initiated to address the effect of glucose-6-phosphate dehydrogenase (G6PD) deficiency on the pathogenesis and the severity of neonatal hyperbilirubinemia (NHB). STUDY DESIGN: A total of 100 newborns with moderate to severe indirect hyperbilirubinemia and 50 normal neonates without hyperbilirubinemia had been enrolled in the current case-control study. All enrolled neonates had been tested for ABO and Rh(D) blood grouping, Total serum bilirubin measurement, complete blood count, morphology, reticulocyte counts, direct Coombs' test, and G6PD enzyme assay. RESULTS: From all enrolled hyperbilirubinemic neonates, 16% were G6PD deficient and this displays a statistically significant difference in comparison to controls (only 6% were G6PD deficient). Also, significant difference was found in the level of serum indirect bilirubin among G6PD-deficient neonate in comparison to G6PD nondeficient neonates which had contributed significantly to the difference in the duration of phototherapy and hospitalization among deficient neonate. Despite this, no significant difference found in the onset of presentation, reticulocytes count, and age of neonates between the two groups (G6PD-deficient and G6PD nondeficient neonates). CONCLUSION: The current study augments the etiological role of G6PD in the causation and severity of NHB in the region; however, in the absence of significant difference in the reticulocytes and the hemoglobin level, the underlying mechanism cannot be backed to the excess hemolysis alone.

Drive-through transcutaneous bilirubin screening for neonatal jaundice: A safe and efficient system during the COVID-19 pandemic.

The coronavirus disease 2019 (COVID-19) cases was on an increasing trend, including in Malaysia. The Malaysian Ministry of Health had implemented a range of measures, such as the use of masks and social distancing, to reduce the risk of transmission. Traditionally, newborns are evaluated for neonatal jaundice using visual assessment, a capillary heel prick and serum bilirubin (SB) sampling in primary health-care clinics. This approach requires the physical presence of both parents and their newborns in the primary health-care clinics, causing crowding and increasing the risk of COVID-19 infections. To alleviate crowding, we implemented the transcutaneous bilirubin drive-through (DT) service, which is an established, non-invasive, painless and rapid method to determine the bilirubin levels. Throughout the screening, both parents and baby will be confined to their car. A total of 1842 babies were screened in our DT setting from April to July 2020. Of the total babies, 298 (16.1%) required venesection for SB measurement and 85 required admission for phototherapy. None with severe jaundice were missed since the implementation of this service. The average test duration per neonate was less than 5 min, while conventional venous bilirubin laboratory testing required an average of 1.5 h per neonate. The cost of the SB laboratory test and consumables was approximately USD 5 per test, with an estimated cost savings of USD 7720. DT screening may be introduced in health-care settings to reduce crowding and eliminate the need of painful blood sampling in newborns.

Decision Accuracy and Safety of Transcutaneous Bilirubin Screening at Intermountain Healthcare.

OBJECTIVE: To quantify the risk that transcutaneous bilirubin (TcB) screening would fail to recommend phototherapy for a neonate who would have qualified for it if total serum bilirubin (TSB) screening were used. STUDY DESIGN: We conducted a quality improvement project where simultaneous TcB and TSB were obtained on neonates ≥35 weeks of gestation during birth hospitalizations in our hospital system. Using our Utah bilirubin management algorithm, we quantified the risk that TcB screening would fail to identify the need for a confirmatory TSB when TSB screening alone would have revealed that phototherapy was indicated. RESULTS: In 3 hospitals, we obtained 727 paired TcB/TSB measurements. Two instances utilized a blood gas radiometer for TSB, and 725 utilized the clinical laboratory-based TSB method. One of the 727 instances had a TcB indicating NO PHOTOTHERAPY, when the simultaneous TSB indicated PHOTOTHERAPY NEEDED. The TSB from that instance was 1 of the 2 from the blood gas radiometer. We estimate the risk of such an error occurring is 1.4 per 1000 TcB measurements (95% CI 0.03-7.6 per 1000). When only the laboratory TSB is used, we estimate the risk of such an error occurring to be 0 per 1000 TcB measurements (95% CI 0.0-5.1 per 1000). CONCLUSIONS: Using TcB for screening at the birth hospital can identify those qualifying for phototherapy, using the Utah guidelines, with 1 of 727 neonates with a blood gas bilirubin and none of 725 with a laboratory-based analysis misidentified as not needing phototherapy when by TSB they did.

Choline supplementation prevents the effects of bilirubin on cerebellar-mediated behavior in choline-restricted Gunn rat pups.

BACKGROUND: Bilirubin is produced by the breakdown of hemoglobin and is normally catabolized and excreted. Neurotoxic accumulation of serum bilirubin often occurs in premature infants. The homozygous Gunn rat lacks uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1), the enzyme needed to biotransform bilirubin. This rodent model of hyperbilirubinemia emulates many aspects of bilirubin toxicity observed in the human infant. We demonstrate that choline supplementation in early postnatal development is neuroprotective in the choline-restricted Gunn rat, when hyperbilirubinemia is induced on postnatal day 5. METHODS: We first compared behaviors and cerebellar weight of pups born to dams consuming regular rat chow to those of dams consuming choline-restricted diets. Second, we measured behaviors and cerebellar weights of pups born to choline-restricted dams, reared on a choline-restricted diet, supplemented with or without choline, and treated with or without sulfadimethoxine (SDMX). RESULTS: A choline-restricted diet did not change the behavioral outcomes, but cerebellar weight was reduced in the choline-restricted group regardless of genotype or SDMX administration. SDMX induced behavioral deficits in jj pups, and choline supplementation improved most behavioral effects and cerebellar weight in SDMX-treated jj rats. CONCLUSIONS: These results suggest that choline may be used as a safe and effective neuroprotective intervention against hyperbilirubinemia in the choline-deficient premature infant. IMPACT: This article investigates the effect of neonatal jaundice/bilirubin neurotoxicity on cerebellar-mediated behaviors. This article explores the potential use of choline as an intervention capable of ameliorating the effect of bilirubin on the choline-restricted developing brain. This article opens the door for future studies on the action of choline in the presence of hyperbilirubinemia, especially in preterm neonates.

Validity of maternal visual assessment of neonatal jaundice: a hospital-based study in Thailand.

BACKGROUND: Hyperbilirubinaemia is a common cause of hospital admission of newborn infants; however, maternal visual assessment of jaundice may reduce unnecessary hospital visits. AIMS: To investigate the validity of maternal visual assessment of neonatal jaundice to identify infants with hyperbilirubinaemia requiring phototherapy or who have significant hyperbilirubinaemia ≥239.4 µmol/L (14 mg/dL). METHODS: A prospective study of the diagnostic accuracy of maternal visual assessment of jaundice was conducted at a university hospital in Bangkok. Mothers were trained to assess for neonatal jaundice using their infant's palms as a skin colour reference. Trained mothers who were blinded to transcutaneous bilirubin or serum bilirubin values assessed their infants and reported 'jaundice' or 'no jaundice', and determined jaundice severity using dermal icterus zones. Sensitivity and negative predictive values were used to assess the validity of visual assessment for neonatal jaundice. RESULTS: In 180 mothers, the median (min/max) transcutaneous or serum bilirubin value in their infants was 177.8 µmol/L (119.7-309.5). The sensitivity and negative predictive values (95% CI) of maternal assessment for detecting hyperbilirubinaemia requiring phototherapy were 91.7% (73.0-99.0) and 96.6% (87.9-99.1), respectively, and for identifying significant hyperbilirubinaemia were 92.9% (76.5-99.1) and 96.6% (87.9-99.1), respectively. The accuracy of maternal report of dermal zones for serum bilirubin levels was only 44.5%. In 56 infants who received a second jaundice assessment, the sensitivity of maternal assessment for detecting increased transcutaneous or serum bilirubin was 93.9% (83.1-98.7). CONCLUSION: Teaching mothers to visually assess their infants for neonatal jaundice was demonstrated to be feasible. ABBREVIATIONS: CI, confidence interval; MB, microbilirubin; min/max, minimum/maximum; NPV, negative predictive value; OPD, outpatient department; PPV, positive predictive value; SD, standard deviation; TcB, transcutaneous bilirubin.

Long-term neurodevelopmental outcomes of significant neonatal jaundice in Taiwan from 2000-2003: a nationwide, population-based cohort study.

Newborns with significant neonatal jaundice (SNJ) would admit for evaluation and/or intervention due to an earlier or more rapid increase in bilirubin level. Bilirubin-induced neurological dysfunction in this population might be underestimated. We aimed to investigate the risk of long-term neurodevelopmental sequelae of SNJ in Taiwan. An SNJ 2000-2003 follow-up cohort consisting of 66,983 neonates was extracted from the nationwide, population-based health insurance database in Taiwan to survey the accumulative incidence of long-term (7-year) neurodevelopmental sequelae in comparison to a reference general-population neonate cohort of 12,579 individuals born in 2000. The SNJ follow-up cohort was furtherly categorized into subgroups according to interventions (phototherapy, intensive phototherapy, and exchange transfusion). The SNJ follow-up cohort exhibited significantly higher cumulative rates of long-term neurodevelopmental sequelae than did the reference cohort (P < 0.05). The risks of infantile cerebral palsy, hearing loss, and developmental delay in the SNJ follow-up cohort were between twice and three times of those in the reference cohort after adjusting for gender, comorbid perinatal disorders and urbanization levels. All intervention subgroups demonstrated higher risks for long-term neurodevelopmental sequelae than the reference cohort (P < 0.05) after adjustment. Patients with SNJ are at risk of developing neurodevelopmental disorders during their growth period. A scheduled follow-up protocol of physical and neurodevelopmental assessment during early childhood for these SNJ patients would potentially be helpful for the early detection of and intervention for neurodevelopmental disorders.

[Analytical and clinical guidelines on neonatal bilirubinemia]. / Recommandations analytiques et cliniques pour l'utilisation de la bilirubinémie en néonatalogie.

The SFBC-CNBH-CNRHP "Neonatal bilirubin" working group performed a biological and clinical study on bilirubin use in neonates for reliable diagnosis and appropriate management of neonatal jaundice. A brief report of a national survey on analytical and biological practices in France is shown. The guidelines of the French Society of Neonatology (SFN) founded the decision of phototherapy set up upon an accurate lab measurement of total serum bilirubin. An abacus is proposed with defined thresholds, as a function of neonate lifetime in hours. However, several studies evidenced poor comparability of results obtained with the different available methods. This situation is partly due to the lack of reference materials, especially for high bilirubin concentrations. Clinical consequences might be observed. We present in this paper the results of a national harmonization study to progress on this issue. Beyond the analytical aspects, the clinical consequences of harmonization defects were investigated. Finally, guidelines for clinical laboratories are proposed, to be locally adapted.

Unbound bilirubin levels in phototherapy-treated preterm infants receiving soy-based lipid emulsion.

BACKGROUND: Phototherapy is an effective treatment for neonatal jaundice. Treatment indication uses total serum bilirubin (TSB), although unbound bilirubin (Bf) more accurately predicts disability risk. The goals of this investigation were to examine the response of Bf and TSB to phototherapy in preterm infants, and we hypothesized that (i) TSB and Bf respond differently; (ii) the relationship between TSB and Bf is altered; and (iii) unexpected Bf elevations are found. METHODS: One hundred and seventeen preterm infants <2 kg at birth and receiving (IL) were enrolled; and measurements of TSB and Bf were obtained. TSB was measured by the diazo method and Bf with a fluorescent Bf sensor BL22P1B11-Rh. RESULTS: Initial mean (± SD) TSB and Bf levels (41.4 ± 6.9 h) were 8.0 ± 9.0 mg/dL and 16.9 ± 12.4 nmol/L (P < 0.05). The rates of rise (ROR) were 0.21 ± 0.10 mg/dL/h for TSB and 0.38 ± 0.33 nmol/L/h for Bf. Phototherapy reduced TSB from 8.0 ± 9.0 to 5.8 ± 9.4 mg/dL (P = 0.068) but Bf did not change (16.9 ± 12.4 to 14.1 ± 9.4 nmol/L P = n.s.). Bf levels were >11 nmol/L in 64, >17 nmol/L in 18, and >22 nmol/L in 7 infants. CONCLUSIONS: Bf and TSB responded differently. While TSB and Bf correlated well before phototherapy, they did not correlate during phototherapy. TSB showed a trend toward a reduction with treatment, Bf did not. While TSB ROR information is not helpful, ROR Bf data can be utilized to anticipate treatment. Potentially high Bf levels existed before and after phototherapy and the mean Bf level at phototherapy termination remained elevated in a significant proportion of infants.

Heme Catabolism and Bilirubin Production in Readmitted Jaundiced Newborns.

We measured end-tidal CO levels in 50 jaundiced newborns readmitted for phototherapy at age 54-244 hours. The median end-tidal CO level was 1.55 ppm, suggesting that hemolysis is not the primary contributor to the hyperbilirubinemia in many readmitted newborns.

Accuracy of Transcutaneous Bilirubin Versus Serum Bilirubin Measurement in Preterm Infants Receiving Phototherapy: A Systematic Review.

BACKGROUND: Jaundice is a common condition among preterm infants in the neonatal intensive care unit (NICU). Total serum bilirubin (TSB) offers a gold standard tool for measurement, but blood sampling can be costly, time-consuming, and not without risks of infection and pain. Transcutaneous bilimeter (TcB) allows for noninvasive assessment of bilirubin. However, due to questions of accuracy the use of the TcB in preterm infants receiving phototherapy has not been widely adapted in the NICU. PURPOSE: To systematically review studies that measure TcB versus TSB bilirubin in preterm infants who are receiving phototherapy. METHODS: A systematic electronic search of databases (CINAHL, EMBASE, Cochrane, Medline, PubMed) was completed for English language publications. No date limitation was placed on the search. Inclusion criteria were based on preterm infants that were in the NICU receiving or had recently received phototherapy. RESULTS: Nine studies of different quantitative study designs were reviewed. A good to strong correlation between TcB and TSB in preterm infants receiving phototherapy was demonstrated. There was a stronger correlation found in studies that examined TcB in unexposed skin areas during phototherapy. IMPLICATIONS FOR PRACTICE: TcB may allow for a reduction in blood sampling, which would reduce painful procedures, reduce the risk of infection and anemia resulting from repeated blood sampling. It also acts as a more time and cost-efficient measurement tool. IMPLICATIONS FOR RESEARCH: Larger scaled quantitative studies on the accuracy of TcB in preterm infants receiving phototherapy are needed to provide more evidence-based data and guide clinical practice on this topic.

Cycled Phototherapy Dose-Finding Study for Extremely Low-Birth-Weight Infants: A Randomized Clinical Trial.

Importance: Cycled (intermittent) phototherapy (PT) might adequately control peak total serum bilirubin (TSB) level and avoid mortality associated with usual care (continuous PT) among extremely low-birth-weight (ELBW) infants (401-1000 g). Objective: To identify a cycled PT regimen that substantially reduces PT exposure, with an increase in mean peak TSB level lower than 1.5 mg/dL in ELBW infants. Design, Setting, and Participants: This dose-finding randomized clinical trial of cycled PT vs continuous PT among 305 ELBW infants in 6 US newborn intensive care units was conducted from March 12, 2014, to November 14, 2018. Interventions: Two cycled PT regimens (≥15 min/h and ≥30 min/h) were provided using a simple, commercially available timer to titrate PT minutes per hour against TSB level. The comparator arm was usual care (continuous PT). Main Outcomes and Measures: Mean peak TSB level and total PT hours through day 14 in all 6 centers and predischarge brainstem auditory-evoked response wave V latency in 1 center. Mortality and major morbidities were secondary outcomes despite limited power. Results: Consent was requested for 452 eligible infants and obtained for 305 (all enrolled) (mean [SD] birth weight, 749 [152] g; gestational age, 25.7 [1.9] weeks; 81 infants [27%] were multiple births; 137 infants [45%] were male; 112 [37%] were black infants; and 107 [35%] were Hispanic infants). Clinical and demographic characteristics of the groups were similar at baseline. After a preplanned interim analysis of 100 infants, the regimen of 30 min/h or more was discontinued, and the study proceeded with 2 arms. Comparing 128 infants receiving PT of 15 min/h or more with 128 infants receiving continuous PT among those surviving to 14 days, mean peak TSB levels were 7.1 vs 6.4 mg/dL (adjusted difference, 0.7; 95% CI, 0.4-1.1 mg/dL) and mean total PT hours were 34 vs 72 (adjusted difference, -39; 95% CI, -45 to -32). Wave V latency adjusted for postmenstrual age was similar in 37 infants receiving 15 min/h or more of PT and 33 infants receiving continuous PT: 7.42 vs 7.32 milliseconds (difference, 0.10; 95% CI, -0.11 to 0.30 millisecond). The relative risk for death was 0.79 (95% CI, 0.40-1.54), with a risk difference of -4.5% (95% CI, -10.9 to 2.0). Morbidities did not differ between groups. Conclusions and Relevance: Cycled PT can substantially reduce total PT with little increase in peak TSB level. A large, randomized trial is needed to assess whether cycled PT would increase survival and survival without impairment in small, preterm infants. Trial Registration: ClinicalTrials.gov Identifier: NCT01944696.

A novel accurate LC-MS/MS method for quantitative determination of Z-lumirubin.

Although phototherapy (PT) is a standard treatment for neonatal jaundice, no validated clinical methods for determination of bilirubin phototherapy products are available. Thus, the aim of our study was to establish a such method for clinical use. To achieve this aim, a LC-MS/MS assay for simultaneous determination of Z-lumirubin (LR) and unconjugated bilirubin (UCB) was conducted. LR was purified after irradiation of UCB at 460 nm. The assay was tested on human sera from PT-treated neonates. Samples were separated on a HPLC system with a triple quadrupole mass spectrometer detector. The instrument response was linear up to 5.8 and 23.4 mg/dL for LR and UCB, respectively, with submicromolar limits of detection and validity parameters relevant for use in clinical medicine. Exposure of newborns to PT raised serum LR concentrations three-fold (p < 0.01), but the absolute concentrations were low (0.37 ± 0.16 mg/dL), despite a dramatic decrease of serum UCB concentrations (13.6 ± 2.2 vs. 10.3 ± 3.3 mg/dL, p < 0.01). A LC-MS/MS method for the simultaneous determination of LR and UCB in human serum was established and validated for clinical use. This method should help to monitor neonates on PT, as well as to improve our understanding of both the kinetics and biology of bilirubin phototherapy products.

Efficacy of double versus single phototherapy in treatment of neonatal jaundice: a meta-analysis.

To assess the efficacy of double phototherapy in managing neonatal jaundice compared to single phototherapy in infants with different birth weight and gestational age. CENTRAL, PubMed, clinicaltrials.gov, and gray literature sources were searched from date of inception of these databases till August 2019. Primary outcome was decline of total serum bilirubin (TSB) per hour. Ten studies were eligible. Our meta-analysis showed significant difference between double phototherapy versus single phototherapy in decline of TSB per hour in preterm infants (standardized mean difference [SMD] = 2.28 [0.79-3.76], p = 0.003) and a significant decrease in TSB levels at 24 h of phototherapy in infants with birth weight ≥ 1500 g (mean difference [MD] = - 61.70 µmol/L, [- 107.96, - 15.43], p = <0.001).Conclusion: Double phototherapy is effective in reducing TSB in infants of different gestational ages and birth weights with the most important finding regarding preterm infants, who are more susceptible to kernicterus.What is Known:• Double phototherapy has shown to be more efficacious than single phototherapy in treating neonatal jaundice.• Double phototherapy efficacy on neonates with different gestational ages and birth weights still remain ambiguous in treating neonatal jaundice.What is New:• The results of this meta-analysis show that double phototherapy is effective in reducing TSB in infants of different gestational ages and birth weights with the most important finding regarding preterm infants, who are more susceptible to kernicterus.

Validation of transcutaneous bilirubinometry during phototherapy for detection and monitoring of neonatal jaundice in a low-income setting.

Background: Severe neonatal jaundice (SNJ) and the associated long-term health sequelae are a significant problem in low-income countries (LIC) where measurement of total serum bilirubin (TSB) is often unavailable. Transcutaneous bilirubinometry (TcB) provides the opportunity for non-invasive, point-of-care monitoring. Few studies have evaluated its agreement with TSB levels during phototherapy in LIC.Aim: To determine agreement between TcB and TSB during phototherapy in a Haitian newborn population and to establish whether TcB can be safely used to guide treatment during phototherapy when TSB is unavailable.Methods: A single-centre prospective study (February to May 2017) in Cap Haïtien, northern Haiti was undertaken. Newborns <7 days of age with clinically detected jaundice were eligible for inclusion. A TcB device (JM-103) was used to screen for newborn jaundice along with a parallel TSB. A strip of black tape was placed across the sternum during phototherapy and uncovered for subsequent TcB measurements. Decisions about phototherapy treatment were based upon UK National Institute of Clinical Excellence (NICE) threshold criteria. Paired TSB and TcB measurements were compared using Bland-Altman methods.Results: The final analysis included 70 parallel TSB/TcB measurements from 35 infants within the first 5 days of life. Nineteen (54.3%) were male and 12 (34.3%) were <35 weeks. Thirty-two (91.4%) were receiving phototherapy. There was good agreement between TSB and TcB. Compared with TSB, TcB tended to over-estimate bilirubin (mean difference 11.1 µmol/L, 95% CI -10.2-32.5 µmol/L). However, at higher bilirubin levels (>250 µmol/L), TcB tended to under-estimate bilirubin compared with TSB and the difference increased.Conclusion: In an LIC setting in which serum bilirubin testing is not commonly available, TcB demonstrates good agreement with TSB and can be safely used to guide jaundice treatment during phototherapy but can lead to over-treatment at lower bilirubin levels and are more inaccurate at higher levels. For TcB levels >250 µmol, confirmation with serum bilirubin should be performed, if available, to avoid under-estimation.Abbreviations: LIC: low income countries; LMIC: low and middle income countries; TcB: transcutaneous bilirubinometry; TSB: transcutaneous serum biliubin.

The accuracy of transcutaneous bilirubinometry in preterm infants.

OBJECTIVE: To evaluate the correlation between total serum and transcutaneous bilirubin and to determine the reliability of transcutaneous bilirubinometry for screening and monitoring of neonatal jaundice among preterms. STUDY DESIGN: Ninety nine infants with gestational ages ≤34 weeks were prospectively enrolled. Babies were classified into three groups as; 24-28, 29-31, and 32-34 weeks. Total serum bilirubin and simultaneous transcutaneous bilirubin were measured before the onset of phototheraphy, during and at 24 h after discontinuing phototherapy. RESULTS: Total serum bilirubin significantly correlated with transcutaneous bilirubin in the whole cohort (r = 0.867, p < 0.001) and in each group before, during and after phototheraphy. Hypotension was the only variable which effects the difference between two methods at postnatal first day of life (p = 0.039). CONCLUSION: Transcutaneous bilirubin levels were highly correlated with total serum bilirubin levels even in 24-28 GW babies. Transcutaneous bilirubin may be useful for screening and monitoring of jaundice in very preterm newborns.

Accuracy of transcutaneous bilirubin on covered skin in preterm and term newborns receiving phototherapy using a JM-105 bilirubinometer.

OBJECTIVE: Determine the suitability of transcutaneous bilirubin (TCB) as a tool to assess the effectiveness of phototherapy on patched skin. STUDY DESIGN: A prospective observational study was conducted. We covered a fragment of skin (sternum) with a photo-opaque patch. Several simultaneous TCB and TSB measurements were performed with the JM-105 bilirubinometer. Bland and Altman test evaluated the agreement between bilirubin levels. RESULT: A total of 217 patients were studied, 48.8% were preterm. The mean difference between TSB and TCB before the start of treatment was 1.07 mg/dL. During phototherapy, differences on covered skin were 0.52, 0.27, and 0.39 mg/dL at 24, 48, and 72 h of therapy respectively. The best correlation was observed at 48 h in preterm infants. CONCLUSION: The measurement of TCB on patched skin (PTCB) is useful for monitoring the response to phototherapy in term and preterm infants. We use a patch with a removable flap that eases successive measures without disturbing the patients.

Associations between neonatal serum bilirubin and childhood hypertension.

Mild hyperbilirubinemia is inversely associated with cardiometabolic diseases in adults. The aim of this study was to evaluate the association between neonatal serum bilirubin levels and childhood hypertension. Data were obtained from the U.S. Collaborative Perinatal Project conducted at 12 U.S. medical centers from 1959 to 1965. This multicenter study recruited participants before phototherapy was routinely used, thereby excluding the influence of phototherapy. In 37,544 newborns (31,819 term and 5,725 preterm births), a generalized linear model and a logistic regression model were used to calculate the linear coefficients and adjusted odds ratios (ORs) of blood pressure and hypertension at 7 years of age based on neonatal serum bilirubin levels. No significant correlation was observed between serum bilirubin at 48 hours after birth and blood pressure at the age of 7 years in the whole study population and in the subgroup of term infants. In preterm infants, a lower total serum bilirubin and unconjugated bilirubin of 3 mg/dl were associated with a higher systolic blood pressure of 62 mmHg (0.38-0.86, p <0.001) and 0.70 mmHg (0.10-1.30, p <0.05) respectively. Relative to a total serum bilirubin level <3 mg/dl among preterm infants, total serum bilirubin levels of 3-6 mg/dl (adjusted OR 1.36; 95% CI: 0.98-1.89), 6-9 mg/dl (adjusted OR 1.35; 95% CI: 0.98-1.85), 9-12 mg/dl (adjusted OR 1.55; 95% CI: 1.10-2.19), and ≥12 mg/dl (adjusted OR 1.42; 95% CI: 1.01-2.00) were associated with higher risks of hypertension. After stratifying for the subtypes of bilirubin, the associations only existed for unconjugated bilirubin. In addition, consistent findings existed when using maximum neonatal serum bilirubin as an exposure factor. Neonatal serum bilirubin levels are positively associated with childhood blood pressure/hypertension in preterm infants. Our findings may shed some light on the role of bilirubin in the prevention of hypertension.

Should transcutaneous bilirubin be measured in preterm infants receiving phototherapy? The relationship between transcutaneous and total serum bilirubin in preterm infants with and without phototherapy.

Our objective was to analyze the relationship between transcutaneous bilirubin (TcB) measured on an unexposed area of skin and total serum bilirubin (TSB) in preterm infants before, during, and after phototherapy (PT). For this purpose paired TSB and TcB levels were measured daily during the first ten days after birth in preterm infants of less than 32 weeks' gestation. TcB was measured with a Dräger Jaundice Meter JM-103 on the covered hipbone. Agreement between TSB and TcB levels was assessed before, during, and after PT. True negative and corresponding false negative percentages were calculated using different TcB cut-off levels. Data are presented as mean (±SD). We obtained 856 paired TcB and TSB levels in 109 preterm infants (66 boys, gestational age 29.4 ± 1.6 weeks and birth weight 1282 g ± 316 g). We found that the difference between TSB and TcB before PT was significantly lower, 44 (±36) µmol/L, than the difference during and after PT, 61 (±29) µmol/L and 63 (±25) µmol/L, respectively; P < 0.01. Blood sampling could be reduced by 42%, with 2% false negatives, when 50 µmol/L was added to the TcB level at 70% of the PT threshold. Our conclusion is that phototherapy enhances underestimation of TSB by TcB in preterms, even if measured on unexposed skin. The use of specific TcB cut-off levels substantially reduces the need for TSB measurements.