Correlation of Total Serum Bilirubin and Transcutaneous Bilirubin at Different Sites in Term Neonates: Impact of Phototherapy

Correlation of Total Serum Bilirubin and Transcutaneous Bilirubin at Different Sites in Term Neonates: Impact of Phototherapy | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Correlation of Total Serum Bilirubin and Transcutaneous Bilirubin at Different Sites in Term Neonates: Impact of Phototherapy Ashwani Kumar Parashar, Ritu Bijarnia, Vishnu Kumar Goyal, Sandeep Choudhary This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7574252/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 27 Oct, 2025 Read the published version in Egyptian Pediatric Association Gazette → Version 1 posted 13 You are reading this latest preprint version Abstract Objective: To evaluate the correlation between total serum bilirubin (TSB) and transcutaneous bilirubin (TcB) at different sites in term neonates before, during, and after phototherapy. Methods: This cross-sectional observational study was conducted at a tertiary care teaching hospital in western Rajasthan from June–December 2022. Term neonates (≥37 weeks) requiring phototherapy were included. TSB was estimated using the Diazo method at baseline, 24 hours after initiation, and 24 hours after completion of phototherapy. Corresponding TcB readings were taken at the sternum (exposed), glabella (eye-shield covered), and pubic symphysis (diaper-covered) using Drager JM-105. Correlation was analyzed using Pearson’s coefficient, and agreement assessed with Bland–Altman plots. Results: Of 850 neonates screened, 130 met inclusion criteria. Before phototherapy, TcB correlated strongly with TSB at the sternum (r = 0.96), with minimal overestimation (bias +0.3 mg/dL). During phototherapy, TcB underestimated TSB, with strongest correlation at the sternum (r = 0.91) and least bias at the pubic symphysis (−0.83 mg/dL). After phototherapy, TcB correlation was highest at the sternum (r = 0.98), with minimal underestimation at the pubic symphysis (−0.11 mg/dL). Conclusions: TcB correlated well with TSB before, during, and after phototherapy. While TcB tended to overestimate TSB before treatment and underestimate it during/after, covered sites such as the pubic symphysis provided reliable measurements, supporting their use in clinical practice. Neonatal jaundice Hyperbilirubinemia Phototherapy Transcutaneous bilirubinometry Serum bilirubin Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 INTRODUCTION Neonatal hyperbilirubinemia is a common condition worldwide, affecting nearly 85% of term neonates and most preterm neonates [1,2]. Accurate assessment of jaundice is essential for timely initiation and discontinuation of phototherapy. Clinical evaluation using Kramer’s rule is often unreliable [2], while total serum bilirubin (TSB) estimation remains the gold standard. However, repeated blood sampling exposes neonates to pain and increases parental anxiety. To address these limitations, transcutaneous bilirubin (TcB) measurement was developed more than 30 years ago. In 2004, the American Academy of Pediatrics (AAP) recommended TcB as a non-invasive alternative for newborn jaundice assessment [3]. TcB is based on optical spectroscopy and is influenced by skin pigmentation, thickness, and phototherapy exposure. Standard measurement sites include the sternum and forehead before phototherapy. However, TcB accuracy during phototherapy is debated, and covered sites such as the glabella and pubic symphysis have not been fully explored. This study aimed to evaluate the reliability of TcB at different sites before, during, and after phototherapy. MATERIALS AND METHODS This cross-sectional observational study was conducted in the Department of Pediatrics at a teaching hospital of western Rajasthan over a period of six months (June 2022–December 2022), after approval by the institutional ethics committee. Written informed consent was obtained from caregivers. Inclusion criteria Term neonates (≥ 37 weeks) aged less than 14 days, both intramural and extramural, requiring phototherapy based on TSB levels. Exclusion criteria Neonates with prior phototherapy or exchange transfusion, conjugated hyperbilirubinemia (conjugated fraction ≥ 15%), hemodynamic instability, extensive bruising, hemangiomas, or skin conditions (e.g., ichthyosis, epidermolysis bullosa) affecting TcB measurement. TSB estimation was performed using the Diazo method when icterus was visible up to the thighs (Kramer’s scale zone 3) or TcB at the sternum exceeded 12 mg/dL. AAP guidelines were followed to determine phototherapy initiation [3]. Each neonate requiring phototherapy had at least three TSB measurements; before starting, 24 hours after initiation, and 24 hours after completion. Corresponding TcB readings were taken at the sternum (exposed), glabella (covered with eye shield), and pubic symphysis (covered with diaper) using the Drager Jaundice Meter JM-105. Phototherapy lights were temporarily paused during TcB/TSB sampling. Statistical analysis Data were analyzed using SPSS version 24. Continuous variables were expressed as mean ± SD and compared using the t-test. Categorical variables were analyzed using the chi-square test. Correlations were assessed using Pearson’s correlation coefficient. Agreement between TcB and TSB was evaluated using Bland–Altman plots. A p-value < 0.05 was considered statistically significant. RESULTS A total of 850 neonates were screened; 133 required phototherapy. Three were excluded (one each for conjugated hyperbilirubinemia, extensive bruising, and hemodynamic instability), leaving 130 neonates for analysis (Table 1 ). Correlation analysis - Before phototherapy, TSB correlated most strongly with TcB at the sternum. -During phototherapy, TSB again correlated best with TcB at the sternum, followed by the pubic symphysis. After phototherapy, TSB correlation remained strongest with the sternum, followed by the pubic symphysis. TcB at the glabella consistently showed the weakest correlation with TSB (Table 2 ). Agreement analysis : Before phototherapy: TcB slightly overestimated TSB, with the lowest bias at the sternum (0.3 mg/dL). During phototherapy TcB underestimated TSB, with the smallest underestimation at the pubic symphysis (0.83 mg/dL). After phototherapy: TcB again underestimated TSB, with the lowest bias at the pubic symphysis (0.11 mg/dL) (Table 3 ). DISCUSSION This study demonstrated that TSB levels correlated strongly with TcB at the sternum in all phases of phototherapy. Notably, TcB at the pubic symphysis also showed excellent correlation (> 0.9) during and after phototherapy, suggesting it as a reliable alternative covered site. Before phototherapy, TcB slightly overestimated TSB (by 0.3 mg/dL at sternum, 0.7 mg/dL at glabella). During phototherapy, TcB underestimated TSB (0.83 mg/dL at pubic symphysis, 1.3 mg/dL at glabella). After phototherapy, underestimation persisted but was minimal at the pubic symphysis (0.11 mg/dL). Strengths The study included a relatively large sample, used prospective design, and obtained simultaneous TSB and TcB measurements at multiple phases. Evaluation at both exposed and covered sites, including rarely studied locations such as the pubic symphysis and glabella, is a novel contribution. Limitations TSB estimation used the Diazo method instead of high-performance liquid chromatography (HPLC), the latter being the gold standard. TcB was measured only at three predefined sites, excluding others such as the axilla. As a single-center study, generalizability is limited. Potential confounders such as skin pigmentation and mode of delivery were not analyzed. Comparison with literature Similar findings have been reported by Cat et al. [1] and Mendoza et al. [2], who also observed overestimation of TSB by TcB before phototherapy, consistent with our pre-phototherapy results. In contrast, Lucanova et al. [4], Katayama et al. [5], Alsaedi et al. [6], and Kosarat et al. [7] predominantly found underestimation of TSB by TcB, which differs from our pre-phototherapy findings but is in line with our observations during and after phototherapy. Such variability across studies may be explained by differences in bilirubin estimation methods, TcB devices used, and population characteristics. Our findings of strong TcB–TSB correlation, with a tendency for TcB to underestimate TSB during and after phototherapy, are consistent with the results of Pendse et al. [8] and Raba et al. [9], who demonstrated reliable correlation during phototherapy but noted systematic underestimation. Similarly, Mandal et al. [10], Kitsommart et al. [11], and Pratesi et al. [12] reported high correlation between TcB and TSB, supporting the reliability of TcB across different populations and devices. In contrast, Juster-Reicher et al. [13] observed lower correlation in the first 8 hours post-phototherapy, while Nagar et al. [14] reported poor TcB–TSB correlation during phototherapy. Grabenhenrich et al. [15] also cautioned against TcB use immediately after phototherapy due to risk of underestimation. Our results are further supported by Taylor et al. [16], who found that TcB reliably correlated with TSB but systematically underestimated serum bilirubin, particularly at higher levels. This is consistent with our observation of underestimation during and after phototherapy. Similarly, Hegyi et al. [17] demonstrated that TcB remains dependable when measured at covered skin sites during phototherapy, aligning with our finding that the pubic symphysis provided accurate estimates in both intra- and post-phototherapy phases. Together, these studies highlight the importance of both timing and site selection when using TcB in neonates undergoing phototherapy. CONCLUSIONS TcB correlated well with TSB before, during, and after phototherapy. However, TcB tended to overestimate TSB before phototherapy and underestimate it during and after treatment. The sternum was the most reliable site before phototherapy, while the pubic symphysis was most accurate during and after phototherapy. Variability compared to prior studies underscores the need for further research to optimize TcB use across clinical contexts. Declarations Funding: None. Conflict of Interest: None declared. Ethical Approval: Approved by the Institutional Ethics Committee. References Cat FC, Cat A, Cicek T, Gulec SG. Evaluation of the relationship between transcutaneous bilirubin measurement and total serum bilirubin in neonatal patients followed for jaundice. Sisli Etfal Hastan Tip Bul. 2021;55(2):262–7. Mendoza-Chuctaya G, Ramos-Chuctaya KR, Maraza-Aquino EJ, Ruiz-Esquivel J, Velázquez-Córdova LA. Accuracy of transcutaneous bilirubin measurement in full-term newborns at 3400 meters above sea level. Bol Med Hosp Infant Mex. 2021;78(2):116–22. American Academy of Pediatrics Subcommittee on Hyperbilirubinemia. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics. 2004;114(1):297–316. Lucanova LC, Matasova K, Zibolen M, Krcho P. Accuracy of transcutaneous bilirubin measurement in newborns after phototherapy. J Perinatol. 2016;36(10):858–61. Katayama Y, Enomoto M, Kikuchi S, Takei A, Ikegami H, Minami H, et al. Transcutaneous bilirubin measurement during phototherapy in term neonates. Pediatr Int. 2017;59(7):686–90. Alsaedi SA. Transcutaneous bilirubin measurement in healthy Saudi term newborns. Saudi Med J. 2016;37(2):142–6. Kosarat S, Khuwuthyakorn V. Accuracy of transcutaneous bilirubin measurement in term newborns. J Med Assoc Thai. 2013;96(2):172–7. Pendse A, Jasani B, Nanavati R, Kabra N. Comparison of transcutaneous bilirubin measurement with total serum bilirubin levels in preterm neonates receiving phototherapy. Indian Pediatr. 2017;54(8):641–3. Raba AA, O’Sullivan A, Miletin J. Transcutaneous bilirubinometry during and after phototherapy in preterm infants: a prospective observational study. BMJ Paediatr Open. 2020;4(1):e000681. Mandal A, Bannerji R, Ray J, Mitra M, Azad S, Basu S. Correlation between transcutaneous bilirubin estimation and total serum bilirubin estimation in neonatal hyperbilirubinemia. BLDE Univ J Health Sci. 2018;3(1):36–42. Kitsommart R, Yangthara B, Wutthigate P, Paes B. Accuracy of transcutaneous bilirubin measured by the BiliCare device in late preterm and term neonates. J Matern Fetal Neonatal Med. 2016;29(22):3641–5. Pratesi S, Boni L, Tofani L, Berti E, Sollai S, Dani C. Comparison of the transcutaneous bilirubinometers BiliCare and Minolta JM-103 in late preterm and term neonates. J Matern Fetal Neonatal Med. 2016;29(18):3014–8. Juster-Reicher A, Flidel-Rimon O, Rozin I, Shinwell ES. Correlation of transcutaneous bilirubinometry and total serum bilirubin levels after phototherapy. J Matern Fetal Neonatal Med. 2014;30(1):1–3. Nagar G, Kumar M. Effect of phototherapy on the diagnostic accuracy of transcutaneous bilirubin in preterm infants. J Clin Neonatol. 2017;6(3):148–53. Grabenhenrich J, Grabenhenrich L, Bührer C, Berns M. Transcutaneous bilirubin after phototherapy in term and preterm infants. Pediatrics. 2014;134(5):e1324–9. Taylor JA, Burgos AE, Flaherman VJ, Chung EK, Simpson EA, Goyal NK, et al. Discrepancies between transcutaneous and serum bilirubin measurements. Pediatrics. 2015;135(2):224–31. Hegyi T, Hiatt IM, Gertner IM, Zanni R, Tolentino T. Transcutaneous bilirubinometry II: Dermal bilirubin kinetics during phototherapy. Pediatr Res. 1983;17(11):888–91. Tables Table 1 Clinico-demographic characteristics of study population (n = 130) S. No. Characteristic Value 1 Mean birth weight 2941 ± 441 g 2 Mean gestational age 38.1 ± 0.9 weeks 3 Male/female ratio 1.08 4 Rh incompatibility 14% ABO incompatibility 20.5% Both 1.5% 5 Mean age at initiation of phototherapy 72.95 ± 16.13 hours 6 Mean duration of phototherapy 40.8 ± 9.1 hours Table 2. Pearson correlation coefficients between TSB and TcB Timing of bilirubin measurement Mean age at sampling (hours) Sternum (r) Glabella (r) Pubic symphysis (r) Prior to phototherapy 72.95 ± 16.13 0.960 (< 0.0001) 0.881 (< 0.0001) 0.882 (< 0.0001) During phototherapy (24h after initiation) 96.90 ± 26.11 0.910 (< 0.0001) 0.873 (< 0.0001) 0.904 (< 0.0001) After phototherapy (24h after completion) 137.15 ± 24.8 0.979 (< 0.0001) 0.938 (< 0.0001) 0.972 (< 0.0001) Table 3. Agreement between TcB at different sites and TSB (Bland–Altman analysis) Timing Sternum (mean diff, 95% CI) Glabella (mean diff, 95% CI) Pubic symphysis (mean diff, 95% CI) Before phototherapy 0.3 (0.20–0.47) 0.7 (0.50–0.86) 1.1 (0.91–1.28) During phototherapy -3.27 (-3.37–-3.17) -1.3 (-1.48–-1.19) -0.83 (-0.91–-0.73) After phototherapy -0.38 (-0.42–-0.33) -0.8 (-0.89–-0.68) -0.11 (-0.17–0.53) Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 27 Oct, 2025 Read the published version in Egyptian Pediatric Association Gazette → Version 1 posted Editorial decision: Revision requested 25 Sep, 2025 Reviews received at journal 24 Sep, 2025 Reviews received at journal 15 Sep, 2025 Reviews received at journal 14 Sep, 2025 Reviewers agreed at journal 12 Sep, 2025 Reviewers agreed at journal 10 Sep, 2025 Reviews received at journal 10 Sep, 2025 Reviewers agreed at journal 09 Sep, 2025 Reviewers agreed at journal 09 Sep, 2025 Reviewers invited by journal 09 Sep, 2025 Editor assigned by journal 09 Sep, 2025 Submission checks completed at journal 09 Sep, 2025 First submitted to journal 09 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7574252","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":515551785,"identity":"54922cb4-1657-4a37-809b-10588be9442c","order_by":0,"name":"Ashwani Kumar Parashar","email":"","orcid":"","institution":"PGIMER","correspondingAuthor":false,"prefix":"","firstName":"Ashwani","middleName":"Kumar","lastName":"Parashar","suffix":""},{"id":515551786,"identity":"85cf9219-b1d2-4028-9efc-ede5ede7e531","order_by":1,"name":"Ritu Bijarnia","email":"","orcid":"","institution":"Dr S N Medical College, 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08:44:02","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":56194,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation between TSB and TcB at the sternum during phototherapy.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7574252/v1/b17b7fea634730bd3500b076.png"},{"id":91511681,"identity":"88c0fb36-6fd1-4f6b-9fa2-75f6fdc7fb9d","added_by":"auto","created_at":"2025-09-17 08:52:02","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":53330,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation between TSB and TcB at the sternum after phototherapy.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7574252/v1/3c2524059e351a19df16c304.png"},{"id":91510463,"identity":"9cdc50f4-bd1e-4e8f-bbe9-2cedce68b5f6","added_by":"auto","created_at":"2025-09-17 08:44:02","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":40675,"visible":true,"origin":"","legend":"\u003cp\u003eBland–Altman plot: TSB vs TcB at sternum before phototherapy.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7574252/v1/f11adc7f2d1e311a4d0d96be.png"},{"id":91513323,"identity":"454bb5c8-aa5c-4645-b11c-ac3b4da8a63b","added_by":"auto","created_at":"2025-09-17 09:00:02","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":46284,"visible":true,"origin":"","legend":"\u003cp\u003eBland–Altman plot: TSB vs TcB at pubic symphysis during phototherapy.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7574252/v1/063caf786bfca14bc6abc077.png"},{"id":91510467,"identity":"bfd6fd52-5e11-4a9b-987e-794ae007c4eb","added_by":"auto","created_at":"2025-09-17 08:44:02","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":40274,"visible":true,"origin":"","legend":"\u003cp\u003eBland–Altman plot: TSB vs TcB at sternum after phototherapy.\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7574252/v1/83dfacb760dcf50fa201e280.png"},{"id":95039772,"identity":"e93975c1-4469-415c-a6e3-1ada546d69f0","added_by":"auto","created_at":"2025-11-03 16:00:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1038794,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7574252/v1/337dc3ff-45b5-4dc1-a69e-c7c8262feb62.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Correlation of Total Serum Bilirubin and Transcutaneous Bilirubin at Different Sites in Term Neonates: Impact of Phototherapy","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eNeonatal hyperbilirubinemia is a common condition worldwide, affecting nearly 85% of term neonates and most preterm neonates [1,2]. Accurate assessment of jaundice is essential for timely initiation and discontinuation of phototherapy. Clinical evaluation using Kramer\u0026rsquo;s rule is often unreliable [2], while total serum bilirubin (TSB) estimation remains the gold standard. However, repeated blood sampling exposes neonates to pain and increases parental anxiety.\u003c/p\u003e\u003cp\u003eTo address these limitations, transcutaneous bilirubin (TcB) measurement was developed more than 30 years ago. In 2004, the American Academy of Pediatrics (AAP) recommended TcB as a non-invasive alternative for newborn jaundice assessment [3]. TcB is based on optical spectroscopy and is influenced by skin pigmentation, thickness, and phototherapy exposure. Standard measurement sites include the sternum and forehead before phototherapy. However, TcB accuracy during phototherapy is debated, and covered sites such as the glabella and pubic symphysis have not been fully explored. This study aimed to evaluate the reliability of TcB at different sites before, during, and after phototherapy.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003eThis cross-sectional observational study was conducted in the Department of Pediatrics at a teaching hospital of western Rajasthan over a period of six months (June 2022\u0026ndash;December 2022), after approval by the institutional ethics committee. Written informed consent was obtained from caregivers.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eInclusion criteria\u003c/strong\u003e\u003cp\u003eTerm neonates (\u0026ge;\u0026thinsp;37 weeks) aged less than 14 days, both intramural and extramural, requiring phototherapy based on TSB levels.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eExclusion criteria\u003c/strong\u003e\u003cp\u003eNeonates with prior phototherapy or exchange transfusion, conjugated hyperbilirubinemia (conjugated fraction\u0026thinsp;\u0026ge;\u0026thinsp;15%), hemodynamic instability, extensive bruising, hemangiomas, or skin conditions (e.g., ichthyosis, epidermolysis bullosa) affecting TcB measurement.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eTSB estimation was performed using the Diazo method when icterus was visible up to the thighs (Kramer\u0026rsquo;s scale zone 3) or TcB at the sternum exceeded 12 mg/dL. AAP guidelines were followed to determine phototherapy initiation [3]. Each neonate requiring phototherapy had at least three TSB measurements; before starting, 24 hours after initiation, and 24 hours after completion. Corresponding TcB readings were taken at the sternum (exposed), glabella (covered with eye shield), and pubic symphysis (covered with diaper) using the Drager Jaundice Meter JM-105. Phototherapy lights were temporarily paused during TcB/TSB sampling.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003cp\u003eData were analyzed using SPSS version 24. Continuous variables were expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD and compared using the t-test. Categorical variables were analyzed using the chi-square test. Correlations were assessed using Pearson\u0026rsquo;s correlation coefficient. Agreement between TcB and TSB was evaluated using Bland\u0026ndash;Altman plots. A p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eA total of 850 neonates were screened; 133 required phototherapy. Three were excluded (one each for conjugated hyperbilirubinemia, extensive bruising, and hemodynamic instability), leaving 130 neonates for analysis (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eCorrelation analysis\u003c/strong\u003e\u003cp\u003e- Before phototherapy, TSB correlated most strongly with TcB at the sternum. -During phototherapy, TSB again correlated best with TcB at the sternum, followed by the pubic symphysis. After phototherapy, TSB correlation remained strongest with the sternum, followed by the pubic symphysis. TcB at the glabella consistently showed the weakest correlation with TSB (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eAgreement analysis\u003c/b\u003e: Before phototherapy: TcB slightly overestimated TSB, with the lowest bias at the sternum (0.3 mg/dL). During phototherapy TcB underestimated TSB, with the smallest underestimation at the pubic symphysis (0.83 mg/dL). After phototherapy: TcB again underestimated TSB, with the lowest bias at the pubic symphysis (0.11 mg/dL) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThis study demonstrated that TSB levels correlated strongly with TcB at the sternum in all phases of phototherapy. Notably, TcB at the pubic symphysis also showed excellent correlation (\u0026gt;\u0026thinsp;0.9) during and after phototherapy, suggesting it as a reliable alternative covered site.\u003c/p\u003e\u003cp\u003eBefore phototherapy, TcB slightly overestimated TSB (by 0.3 mg/dL at sternum, 0.7 mg/dL at glabella). During phototherapy, TcB underestimated TSB (0.83 mg/dL at pubic symphysis, 1.3 mg/dL at glabella). After phototherapy, underestimation persisted but was minimal at the pubic symphysis (0.11 mg/dL).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eStrengths\u003c/strong\u003e\u003cp\u003eThe study included a relatively large sample, used prospective design, and obtained simultaneous TSB and TcB measurements at multiple phases. Evaluation at both exposed and covered sites, including rarely studied locations such as the pubic symphysis and glabella, is a novel contribution.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eLimitations\u003c/strong\u003e\u003cp\u003eTSB estimation used the Diazo method instead of high-performance liquid chromatography (HPLC), the latter being the gold standard. TcB was measured only at three predefined sites, excluding others such as the axilla. As a single-center study, generalizability is limited. Potential confounders such as skin pigmentation and mode of delivery were not analyzed.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eComparison with literature\u003c/strong\u003e\u003cp\u003eSimilar findings have been reported by Cat et al. [1] and Mendoza et al. [2], who also observed overestimation of TSB by TcB before phototherapy, consistent with our pre-phototherapy results. In contrast, Lucanova et al. [4], Katayama et al. [5], Alsaedi et al. [6], and Kosarat et al. [7] predominantly found underestimation of TSB by TcB, which differs from our pre-phototherapy findings but is in line with our observations during and after phototherapy. Such variability across studies may be explained by differences in bilirubin estimation methods, TcB devices used, and population characteristics.\u003c/p\u003e\u003c/p\u003e\u003cp\u003eOur findings of strong TcB\u0026ndash;TSB correlation, with a tendency for TcB to underestimate TSB during and after phototherapy, are consistent with the results of Pendse et al. [8] and Raba et al. [9], who demonstrated reliable correlation during phototherapy but noted systematic underestimation. Similarly, Mandal et al. [10], Kitsommart et al. [11], and Pratesi et al. [12] reported high correlation between TcB and TSB, supporting the reliability of TcB across different populations and devices. In contrast, Juster-Reicher et al. [13] observed lower correlation in the first 8 hours post-phototherapy, while Nagar et al. [14] reported poor TcB\u0026ndash;TSB correlation during phototherapy. Grabenhenrich et al. [15] also cautioned against TcB use immediately after phototherapy due to risk of underestimation.\u003c/p\u003e\u003cp\u003eOur results are further supported by Taylor et al. [16], who found that TcB reliably correlated with TSB but systematically underestimated serum bilirubin, particularly at higher levels. This is consistent with our observation of underestimation during and after phototherapy. Similarly, Hegyi et al. [17] demonstrated that TcB remains dependable when measured at covered skin sites during phototherapy, aligning with our finding that the pubic symphysis provided accurate estimates in both intra- and post-phototherapy phases. Together, these studies highlight the importance of both timing and site selection when using TcB in neonates undergoing phototherapy.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"CONCLUSIONS","content":"\u003cp\u003eTcB correlated well with TSB before, during, and after phototherapy. However, TcB tended to overestimate TSB before phototherapy and underestimate it during and after treatment. The sternum was the most reliable site before phototherapy, while the pubic symphysis was most accurate during and after phototherapy. Variability compared to prior studies underscores the need for further research to optimize TcB use across clinical contexts.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e None.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eConflict of Interest:\u003c/strong\u003e None declared.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eEthical Approval:\u003c/strong\u003e Approved by the Institutional Ethics Committee.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eCat FC, Cat A, Cicek T, Gulec SG. Evaluation of the relationship between transcutaneous bilirubin measurement and total serum bilirubin in neonatal patients followed for jaundice. Sisli Etfal Hastan Tip Bul. 2021;55(2):262\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003eMendoza-Chuctaya G, Ramos-Chuctaya KR, Maraza-Aquino EJ, Ruiz-Esquivel J, Vel\u0026aacute;zquez-C\u0026oacute;rdova LA. Accuracy of transcutaneous bilirubin measurement in full-term newborns at 3400 meters above sea level. Bol Med Hosp Infant Mex. 2021;78(2):116\u0026ndash;22.\u003c/li\u003e\n\u003cli\u003eAmerican Academy of Pediatrics Subcommittee on Hyperbilirubinemia. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics. 2004;114(1):297\u0026ndash;316.\u003c/li\u003e\n\u003cli\u003eLucanova LC, Matasova K, Zibolen M, Krcho P. Accuracy of transcutaneous bilirubin measurement in newborns after phototherapy. J Perinatol. 2016;36(10):858\u0026ndash;61.\u003c/li\u003e\n\u003cli\u003eKatayama Y, Enomoto M, Kikuchi S, Takei A, Ikegami H, Minami H, et al. Transcutaneous bilirubin measurement during phototherapy in term neonates. Pediatr Int. 2017;59(7):686\u0026ndash;90.\u003c/li\u003e\n\u003cli\u003eAlsaedi SA. Transcutaneous bilirubin measurement in healthy Saudi term newborns. Saudi Med J. 2016;37(2):142\u0026ndash;6.\u003c/li\u003e\n\u003cli\u003eKosarat S, Khuwuthyakorn V. Accuracy of transcutaneous bilirubin measurement in term newborns. J Med Assoc Thai. 2013;96(2):172\u0026ndash;7.\u003c/li\u003e\n\u003cli\u003ePendse A, Jasani B, Nanavati R, Kabra N. Comparison of transcutaneous bilirubin measurement with total serum bilirubin levels in preterm neonates receiving phototherapy. Indian Pediatr. 2017;54(8):641\u0026ndash;3.\u003c/li\u003e\n\u003cli\u003eRaba AA, O\u0026rsquo;Sullivan A, Miletin J. Transcutaneous bilirubinometry during and after phototherapy in preterm infants: a prospective observational study. BMJ Paediatr Open. 2020;4(1):e000681.\u003c/li\u003e\n\u003cli\u003eMandal A, Bannerji R, Ray J, Mitra M, Azad S, Basu S. Correlation between transcutaneous bilirubin estimation and total serum bilirubin estimation in neonatal hyperbilirubinemia. BLDE Univ J Health Sci. 2018;3(1):36\u0026ndash;42.\u003c/li\u003e\n\u003cli\u003eKitsommart R, Yangthara B, Wutthigate P, Paes B. Accuracy of transcutaneous bilirubin measured by the BiliCare device in late preterm and term neonates. J Matern Fetal Neonatal Med. 2016;29(22):3641\u0026ndash;5.\u003c/li\u003e\n\u003cli\u003ePratesi S, Boni L, Tofani L, Berti E, Sollai S, Dani C. Comparison of the transcutaneous bilirubinometers BiliCare and Minolta JM-103 in late preterm and term neonates. J Matern Fetal Neonatal Med. 2016;29(18):3014\u0026ndash;8.\u003c/li\u003e\n\u003cli\u003eJuster-Reicher A, Flidel-Rimon O, Rozin I, Shinwell ES. Correlation of transcutaneous bilirubinometry and total serum bilirubin levels after phototherapy. J Matern Fetal Neonatal Med. 2014;30(1):1\u0026ndash;3.\u003c/li\u003e\n\u003cli\u003eNagar G, Kumar M. Effect of phototherapy on the diagnostic accuracy of transcutaneous bilirubin in preterm infants. J Clin Neonatol. 2017;6(3):148\u0026ndash;53.\u003c/li\u003e\n\u003cli\u003eGrabenhenrich J, Grabenhenrich L, B\u0026uuml;hrer C, Berns M. Transcutaneous bilirubin after phototherapy in term and preterm infants. Pediatrics. 2014;134(5):e1324\u0026ndash;9.\u003c/li\u003e\n\u003cli\u003eTaylor JA, Burgos AE, Flaherman VJ, Chung EK, Simpson EA, Goyal NK, et al. Discrepancies between transcutaneous and serum bilirubin measurements. Pediatrics. 2015;135(2):224\u0026ndash;31.\u003c/li\u003e\n\u003cli\u003eHegyi T, Hiatt IM, Gertner IM, Zanni R, Tolentino T. Transcutaneous bilirubinometry II: Dermal bilirubin kinetics during phototherapy. Pediatr Res. 1983;17(11):888\u0026ndash;91.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv\u003eTable 1\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eClinico-demographic characteristics of study population (n = 130)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eS. No.\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCharacteristic\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eValue\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMean birth weight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2941 ± 441 g\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMean gestational age\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.1 ± 0.9 weeks\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMale/female ratio\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRh incompatibility\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eABO incompatibility\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20.5%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBoth\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.5%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMean age at initiation of phototherapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e72.95 ± 16.13 hours\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMean duration of phototherapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.8 ± 9.1 hours\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cdiv\u003e\n \u003ctable id=\"Tab2\" border=\"1\"\u003e\u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv\u003e\n \u003cdiv align=\"char\"\u003e\u003cstrong\u003eTable 2. Pearson correlation coefficients between TSB and TcB\u003c/strong\u003e\u003c/div\u003e\n \u003ctable id=\"Taba\" border=\"1\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTiming of bilirubin measurement\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean age at sampling (hours)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSternum (r)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGlabella (r)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePubic symphysis (r)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePrior to phototherapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e72.95 ± 16.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.960 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.881 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.882 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDuring phototherapy (24h after initiation)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e96.90 ± 26.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.910 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.873 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.904 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter phototherapy (24h after completion)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e137.15 ± 24.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.979 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.938 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.972 (\u0026lt; 0.0001)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv\u003e\n \u003ctable id=\"Tab3\" border=\"1\"\u003e\u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv\u003e\n \u003cdiv align=\"char\"\u003e\u003cstrong\u003eTable 3. Agreement between TcB at different sites and TSB (Bland–Altman analysis)\u003c/strong\u003e\u003c/div\u003e\n \u003ctable id=\"Tabb\" border=\"1\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eTiming\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSternum (mean diff, 95% CI)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGlabella (mean diff, 95% CI)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePubic symphysis (mean diff, 95% CI)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBefore phototherapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.3 (0.20–0.47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.7 (0.50–0.86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.1 (0.91–1.28)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDuring phototherapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-3.27 (-3.37–-3.17)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-1.3 (-1.48–-1.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-0.83 (-0.91–-0.73)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter phototherapy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-0.38 (-0.42–-0.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-0.8 (-0.89–-0.68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e-0.11 (-0.17–0.53)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"egyptian-pediatric-association-gazette","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"epag","sideBox":"Learn more about [Egyptian Pediatric Association Gazette](https://epag.springeropen.com)","snPcode":"43054","submissionUrl":"https://submission.springernature.com/new-submission/43054/3?","title":"Egyptian Pediatric Association Gazette","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Neonatal jaundice, Hyperbilirubinemia, Phototherapy, Transcutaneous bilirubinometry, Serum bilirubin","lastPublishedDoi":"10.21203/rs.3.rs-7574252/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7574252/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective:\u003c/strong\u003e To evaluate the correlation between total serum bilirubin (TSB) and transcutaneous bilirubin (TcB) at different sites in term neonates before, during, and after phototherapy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e This cross-sectional observational study was conducted at a tertiary care teaching hospital in western Rajasthan from June–December 2022. Term neonates (≥37 weeks) requiring phototherapy were included. TSB was estimated using the Diazo method at baseline, 24 hours after initiation, and 24 hours after completion of phototherapy. Corresponding TcB readings were taken at the sternum (exposed), glabella (eye-shield covered), and pubic symphysis (diaper-covered) using Drager JM-105. Correlation was analyzed using Pearson’s coefficient, and agreement assessed with Bland–Altman plots.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Of 850 neonates screened, 130 met inclusion criteria. Before phototherapy, TcB correlated strongly with TSB at the sternum (r = 0.96), with minimal overestimation (bias +0.3 mg/dL). During phototherapy, TcB underestimated TSB, with strongest correlation at the sternum (r = 0.91) and least bias at the pubic symphysis (−0.83 mg/dL). After phototherapy, TcB correlation was highest at the sternum (r = 0.98), with minimal underestimation at the pubic symphysis (−0.11 mg/dL).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e TcB correlated well with TSB before, during, and after phototherapy. While TcB tended to overestimate TSB before treatment and underestimate it during/after, covered sites such as the pubic symphysis provided reliable measurements, supporting their use in clinical practice.\u003c/p\u003e","manuscriptTitle":"Correlation of Total Serum Bilirubin and Transcutaneous Bilirubin at Different Sites in Term Neonates: Impact of Phototherapy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-17 08:43:58","doi":"10.21203/rs.3.rs-7574252/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-25T04:17:04+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-25T03:06:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-15T21:02:42+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-14T20:20:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"306230101654833177696279303775330740987","date":"2025-09-12T15:47:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"230502774255386737433832774105434942175","date":"2025-09-11T00:33:31+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-10T18:38:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"109581962922809994764204668019170402851","date":"2025-09-09T20:18:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"270835088471682058840336441861002634048","date":"2025-09-09T13:42:55+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-09T13:39:00+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-09T13:30:05+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-09T13:29:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"Egyptian Pediatric Association Gazette","date":"2025-09-09T13:09:45+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"egyptian-pediatric-association-gazette","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"epag","sideBox":"Learn more about [Egyptian Pediatric Association Gazette](https://epag.springeropen.com)","snPcode":"43054","submissionUrl":"https://submission.springernature.com/new-submission/43054/3?","title":"Egyptian Pediatric Association Gazette","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"5b02dc74-b76f-4e04-bcff-220c58da93c5","owner":[],"postedDate":"September 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-03T15:59:09+00:00","versionOfRecord":{"articleIdentity":"rs-7574252","link":"https://doi.org/10.1186/s43054-025-00463-7","journal":{"identity":"egyptian-pediatric-association-gazette","isVorOnly":false,"title":"Egyptian Pediatric Association Gazette"},"publishedOn":"2025-10-27 15:56:50","publishedOnDateReadable":"October 27th, 2025"},"versionCreatedAt":"2025-09-17 08:43:58","video":"","vorDoi":"10.1186/s43054-025-00463-7","vorDoiUrl":"https://doi.org/10.1186/s43054-025-00463-7","workflowStages":[]},"version":"v1","identity":"rs-7574252","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7574252","identity":"rs-7574252","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}