A chromosomal-effect study of intensive phototherapy versus conventional phototherapy in newborns with jaundice

Splanchnic and cerebral oxygenation during cyclic phototherapy in preterm infants with hyperbilirubinemia

Cyclic phototherapy (cPT) can achieve a reduction in total serum bilirubin comparable to that achieved with standard continuous PT in preterm infants. Our aim was to assess the effect of cPT on splanchnic (rSO2S) and cerebral (rSO2C) oxygenation measured by near-infrared spectroscopy (NIRS). We prospectively studied 16 infants with a gestational age of 25-34 weeks with hyperbilirubinemia requiring PT. Splanchnic regional oxygenation (rSO2S), oxygen extraction fraction (FOES), and cerebro-splanchnic oxygenation ratio (CSOR) were recorded before, during, and after cPT discontinuation. We found that rSO2S, FOES, and CSOR did not change during the study period. The overall duration of single or multiple courses of PT was 6.5 (6.0-13.5) h, but by cycling PT, the actual exposure was 3.0 (1.5-4.9) h. Twelve patients (75%) required 15 min/h cPT, and four (25%) required prolonging cPT to 30 min/h. None of the patients developed enteral feeding intolerance. Conclusions: cPT treatment of hyperbilirubinemia in preterm infants does not affect splanchnic oxygenation or intestinal oxygen blood extraction, likely due to the short exposure to PT light, and it could contribute to decreasing the risk of feeding intolerance.

Blue-Green (~480 nm) versus Blue (~460 nm) Light for Newborn Phototherapy-Safety Considerations

We have previously shown that the phototherapy of hyperbilirubinemic neonates using blue-green LED light with a peak wavelength of ~478 nm is 31% more efficient for removing unconjugated bilirubin from circulation than blue LED light with a peak wavelength of ~452 nm. Based on these results, we recommended that the phototherapy of hyperbilirubinemic newborns be practiced with light of ~480 nm. Aim: Identify and discuss the most prominent potential changes that have been observed in the health effects of phototherapy using either blue fluorescent- or blue LED light and speculate on the expected effects of changing to blue-green LED light phototherapy. Search the phototherapy literature using the terms neonate, hyperbilirubinemia, and phototherapy in the PubMed and Embase databases. Transitioning from blue fluorescent light to blue-green LED light will expose neonates to less light in the 400-450 nm spectral range, potentially leading to less photo-oxidation and geno-/cytotoxicity, reduced risk of cancer, and decreased mortality in extremely low-birthweight neonates. The riboflavin level may decline, and the increased production and retention of bronze pigments may occur in predisposed neonates due to enhanced lumirubin formation. The production of pre-inflammatory cytokines may rise. Hemodynamic responses and transepidermal water loss are less likely to occur. The risk of hyperthermia may decrease with the use of blue-green LED light and the risk of hypothermia may increase. Parent-neonate attachment and breastfeeding will be positively affected because of the shortened duration of phototherapy. The latter may also lead to a significant reduction in the cost of phototherapy procedures as well as the hospitalization process.

Is neonatal phototherapy associated with a greater risk of childhood cancers?

Background

Neonatal phototherapy (NNPT) has long been used as an effective and relatively safe method of treating neonatal hyperbilirubinemia. Considering the subsequent evidence of long-term impacts of NNPT such as malignancies, this study was conducted to evaluate the relationship between NNPT and childhood cancers.

Methods

This case-control study assessed 116 children up to 4 years old with every kind of cancer referred to the Oncology department of Afzalipour hospital, Kerman, Iran, from 2011 to 18. Moreover, 116 pediatric patients without cancer hospitalized at the same Center were included after sex and age matching as the control group. The history of phototherapy and its duration were evaluated in these two groups.

Results

We found no association between the NNPT and malignancies in children. However, high intensive phototherapy was higher historically among affected cancerous patients than in non-cancerous cases without any statistically significant difference (25% vs 19%; P = 0.26). Maternal educational level and history of maternal infection during pregnancy, which initially appeared to be two factors associated with malignancy in single variable regression analyses, were not significant based on the adjusted models.

Conclusions

The results did not show a positive correlation between NNPT and childhood cancers, which may partly be due to the relatively small sample size of the study. However, some other evidence is worrisome enough that NNPT should not be considered risk-free. Additional multi-centric studies should be undertaken to specify that phototherapy is really safe.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03412-0.

Update on Phototherapy and Childhood Cancer in a Northern California Cohort

OBJECTIVES

We aimed to reassess the relationship between phototherapy and cancer in an extended version of a previous cohort and to replicate a report from Quebec of increased cancer risk after phototherapy beginning at age 4 years.

METHODS

This cohort study included 139 100 children born at ≥35 weeks' gestation from 1995 to 2017, followed through March 16, 2019, in Kaiser Permanente Northern California hospitals who had a qualifying bilirubin level from -3 mg/dL to +4.9 mg/dL from the American Academy of Pediatrics phototherapy threshold; an additional 40 780 children and 5 years of follow-up from our previous report. The exposure was inpatient phototherapy (yes or no), and the outcomes were various types of childhood cancer. We used Cox proportional hazard models, controlling for propensity-score quintiles, and allowed for time-dependent exposure effects to assess for the risk of cancer after a latent period.

RESULTS

Over a mean (SD) follow-up of 8.2 (5.7) years, the crude incidence of cancer per 100 000 person-years was 25.1 among those exposed to phototherapy and 19.2 among those not exposed (233 cases of cancer). After propensity adjustment, phototherapy was not associated with any cancer (hazard ratio [HR]: 1.13, 95% confidence interval [CI]: 0.83-1.54), hematopoietic cancer (HR: 1.17, 95% CI: 0.74-1.83), or solid tumors (HR: 1.01, 95% CI: 0.65-1.58). We also found no association with cancer diagnoses at age ≥4 years.

CONCLUSIONS

We did not confirm previous, concerning associations between phototherapy and adjusted risk of any cancer, nonlymphocytic leukemia, or brain and/or central nervous systems tumors in later childhood.

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.

Increased risk of hemangioma after exposure to neonatal phototherapy in infants with predisposing risk factors

AIM

To determine the relationship between neonatal phototherapy and future risk of clinically significant hemangioma.

METHODS

We analysed a cohort of 678 879 infants born after 34 weeks gestation comprising 3 975 242 person-years of follow-up over 11 years (2006-2016). The exposure was phototherapy the first 28 days of life. The outcome was hemangioma that required in-hospital treatment during follow-up. We estimated hazard ratios (HR) and 95% confidence intervals (CI) for the association of phototherapy with risk of hemangioma, accounting for preterm birth, low birthweight and congenital anomalies.

RESULTS

The incidence of hemangioma was greater in neonates who received phototherapy than in untreated infants, but there was no association in adjusted models (HR 1.19, 95% CI 0.89-1.58). Risk of hemangioma was elevated in infants who received phototherapy and were born late preterm (HR 2.35, 95% CI 1.51-3.64), with low birthweight (HR 1.91, 95% CI 1.12-3.24), or with anomalies (HR 5.09, 95% CI 3.42-7.58). Without phototherapy, these three risk factors were more weakly associated with hemangioma.

CONCLUSION

Neonatal phototherapy in infants with predisposing risk factors may increase the chance of hemangioma, but confirmation in further studies is needed.

Green light-emitting diode phototherapy for neonatal hyperbilirubinemia: Randomized controlled trial

BACKGROUND

The main photochemical pathway in phototherapy for neonatal hyperbilirubinemia is the production and elimination (in bile or urine) of cyclobilirubin, which is a structural photoisomer of bilirubin, and which is most efficiently produced by green light. Green light-emitting diode (LED) phototherapy, however, has not been evaluated in the clinical setting because it is not recommended in American Academy of Pediatrics guidelines. We therefore compared the efficacy of green LED phototherapy and blue LED phototherapy in patients with neonatal hyperbilirubinemia.

METHODS

In this prospective randomized controlled trial, neonates with hyperbilirubinemia were randomly allocated to a green LED or blue LED phototherapy group. Both groups underwent 24 h of phototherapy, and blood was sampled before and after 24 h of phototherapy. Total serum bilirubin (TSB) was measured using enzymatic methods and bilirubin photoisomers were measured on high-performance liquid chromatography.

RESULTS

Thirty-four infants were randomized (green, n = 16; blue, n = 18). TSB decreased significantly from 15.3 ± 1.5 to 13.9 ± 1.5 mg/dL in the green LED group (P < 0.01) and from 16.2 ± 1.3 to 14.5 ± 1.7 mg/dL in the blue LED group (P < 0.01) after 24 h of phototherapy. No significant difference was found in TSB reduction after phototherapy between the groups.

CONCLUSIONS

Both light sources produced a significant reduction in TSB, indicating clinical effectiveness.

The effect of phototherapy on sister chromatid exchange with different light density in newborn hyperbilirubinemia

Aim

Concerns of possible genotoxic effects of hyperbilirubinemia and phototherapy were raised from experimental and observational studies in neonates. The purpose of this study was to assess the effect of hyperbilirubinemia and phototherapy with three different methods on DNA damage by investigating sister chromatid exchange frequency.

Material and Methods

Patients whose gestational ages were >37 weeks and bilirubin levels above phototherapy limits were enrolled into three groups and each group was planned to receive 25 babies. Group 1 received enhanced light-emitting diode phototherapy, group 2 had light-emitting diode phototherapy, and group 3 received conventional phototherapy. Infants with hyperbilirubinemia but did not require phototherapy comprised the control group, which was subdivided into two groups regarding bilirubin levels (<or>10mg/dL). Blood samples were collected before and after phototherapy for sister chromatid exchange frequency and samples were examined by a biologist who was blinded to the study groups.

Results

The mean pre-treatment sister chromatid exchange frequency was 1.41±0.34/cell, post-treatment 2.65±0.68/cell, and 1.61±0.61/cell for the control group (p<0.05). A statistically significant increase in sister chromatid exchange frequency after phototherapy was observed in all three intervention groups (p values: 0.01, 0.01, and 0.008, respectively). When the treatment groups were compared with each other in terms of irradiance, no significant difference was found (p=0.08).

Conclusions

Phototherapy causes an increase in the frequency of sister chromatid exchange regardless of the irradiance. Phototherapy could have some genotoxic adverse effects on chromosomes; however, further investigations are warranted to enlighten as to whether these effects are permanent or clinically important.

An Increased Genotoxic Risk in Lymphocytes from Phototherapy-Treated Hyperbilirubinemic Neonates

BACKGROUND

Phototherapy is believed to be a safe method for the management of hyperbilirubinemia. However, there are some controversial issues regarding the genotoxic effects of phototherapy on DNA. The aim of this study was to investigate morphologically both phototherapy-induced DNA double-strand breaks (DSBs) and apoptosis in lymphocytes derived from jaundiced and non-jaundiced neonates.

METHODS

Newborns were divided into three groups, including phototherapy-treated (PT, n=30) jaundiced newborns with total serum bilirubin (TSB) levels >15 mg/dl, non-treated jaundiced newborns (C+, n=27), as positive, as well as healthy negative (C-, n=30) controls with TSB levels ranging from 10 and 15 mg/dl and less than 5 mg/dl, respectively. Lymphocytes were isolated from whole blood samples by Ficoll-isopaque density gradient centrifugation and then assessed for DNA damage and apoptosis before and 24 hours after incubation at 37°C in 5% CO2 using the neutral comet assay.

RESULTS

DSB levels were significantly much higher in the PT group compared to the controls before incubation but decreased remarkably after the incubation period. As expected, no statistical differences were found between the two control groups before and after incubations. The frequency of apoptotic cells showed no significant differences among all the three groups before incubation; however, it was significantly increased in the PT group after incubation.

CONCLUSION

It seems that phototherapy in jaundiced infants is able not only to induce apoptosis in newborn lymphocytes but also to affect indirectly DNA integrity.

Neonatal Phototherapy and Infantile Cancer

OBJECTIVE

To determine whether neonatal phototherapy is associated with cancer in the first year after birth.

METHODS

We analyzed a data set from the California Office of Statewide Health Planning and Development that was created by linking birth certificates, death certificates, and hospital discharge abstracts up to age 1 year. Subjects were 5 144 849 infants born in California hospitals at ≥35 weeks' gestation from 1998 to 2007. We used International Classification of Diseases, Ninth Revision codes to identify phototherapy at <15 days and discharge diagnoses of cancer at 61 to 365 days. We adjusted for potential confounding variables by using traditional and propensity-adjusted logistic regression models.

RESULTS

Cancer was diagnosed in 58/178 017 infants with diagnosis codes for phototherapy and 1042/4 966 832 infants without such codes (32.6/100 000 vs 21.0/100 000; relative risk 1.6; 95% confidence interval [CI], 1.2-2.0, P = .002). In propensity-adjusted analyses, associations were seen between phototherapy and overall cancer (adjusted odds ratio [aOR] 1.4; 95% CI, 1.1-1.9), myeloid leukemia (aOR 2.6; 95% CI, 1.3-5.0), and kidney cancer (aOR 2.5; 95% CI, 1.2-5.1). The marginal propensity-adjusted absolute risk increase for cancer after phototherapy in the total population was 9.4/100 000 (number needed to harm of 10 638). Because of the higher baseline risk of cancer in infants with Down syndrome, the number needed to harm was 1285.

CONCLUSIONS

Phototherapy may slightly increase the risk of cancer in infancy, although the absolute risk increase is small. This risk should be considered when making phototherapy treatment decisions, especially for infants with bilirubin levels below current treatment guidelines.

Retrospective Cohort Study of Phototherapy and Childhood Cancer in Northern California

OBJECTIVE

To investigate the association between neonatal phototherapy use and childhood cancer.

METHODS

This retrospective cohort study included 499 621 children born at ≥35 weeks' gestation from 1995 to 2011 in Kaiser Permanente Northern California hospitals, who survived to hospital discharge and were followed ≥60 days. We obtained data on home and inpatient phototherapy, covariates, and cancer incidence from electronic records. We used propensity-adjusted Cox and Poisson models to control for confounding and unequal follow-up times.

RESULTS

There were 60 children with a diagnosis of cancer among 39 403 exposed to phototherapy (25 per 100 000 person-years), compared with 651 of 460 218 unexposed children (18 per 100 000 person-years; incidence rate ratio [IRR] 1.4; P = .01). Phototherapy was associated with increased rates of any leukemia (IRR 2.1; P = .0007), nonlymphocytic leukemia (IRR 4.0; P = .0004), and liver cancer (IRR 5.2; P = .04). With adjustment for a propensity score that incorporated bilirubin levels, chromosomal disorders, congenital anomalies, and other covariates, associations were no longer statistically significant: Adjusted hazard ratios (95% confidence intervals) were 1.0 (0.7-1.6) for any cancer, 1.6 (0.8-3.5) for any leukemia, 1.9 (0.6-6.9) for nonlymphocytic leukemia, and 1.4 (0.2-12) for liver cancer. Upper limits of 95% confidence intervals for adjusted 10-year excess risk were generally <0.1% but reached 4.4% for children with Down syndrome.

CONCLUSIONS

Although phototherapy use was associated with increased cancer rates (particularly nonlymphocytic leukemia), control for confounding variables eliminated or attenuated the associations. Nonetheless, the possibility of even partial causality suggests that avoiding unnecessary phototherapy may be prudent.

Effects of blue light phototherapy on DNA integrity in preterm newborns

In previous studies, exposure to phototherapy, but not oxygen therapy, resulted in damage to genetic material in newborns. The objective of this study was to determine whether micronucleated erythrocytes (MNE) increased in preterm newborns (PNBs) who were exposed to blue light phototherapy lamps. MNE of mature organisms are rapidly eliminated by the spleen, and the presence of MNE has been related to immaturity in some species. Furthermore, PNBs present spontaneous MNE. Blood samples were taken from 17 PNBs at birth to establish baseline frequencies (0 h). After beginning blue light phototherapy, blood samples were obtained from 11 of these PNBs at 24-h intervals for 96 h, after the baseline sample. MNE and micronucleated polychromatic erythrocytes (MNPCE) were counted. The basal values of MNE and MNPCE from 17 PNBs were 0.62 ± 0.48 and 1.52 ± 1.28 (‰), respectively, and no increase in MNE or MNPCE was observed in the serial samples of 11 PNBs exposed to blue light and oxygen therapies, though previous studies reported increases using other types of lamps. In conclusion, under the conditions described no increase in the number of MNE or MNPCE was observed in the peripheral blood of PNBs exposed to blue light phototherapy.

Efficacy of light-emitting diode versus other light sources for treatment of neonatal hyperbilirubinemia: a systematic review and meta-analysis

Various light-emitting diode (LED) phototherapy devices have been trialled on the assumption of a more effective spectral distribution of the light emitted. We reviewed the current literature to determine whether LED is more effective than other types of phototherapy. Eligible studies were randomized controlled trials of LED versus other phototherapies. Studies were found to be of medium quality based on a components approach. Data were statistically aggregated within a very homogeneous population (term or late preterm neonates). Results appeared robust at sensitivity analysis. Five hundred and eleven neonates were included in the meta-analysis. LED and other phototherapy devices appeared to be equally effective in reducing total serum bilirubin (TSB) in term or late preterm neonates. The pooled mean TSB rate of decrease was 3.269 μmol/L/h (0.191 mg/dL/h) and 3.074 μmol/L/h (0.18 mg/dL/h) in the LED and conventional arms, respectively [average difference in TSB rate of decrease = 0.194 μmol/L/h (0.011 mg/dL/h) in favour of LED phototherapy; p = 0.378].

CONCLUSION

No significant difference in TSB rate of decrease was detected between LED and other types of phototherapy. Further randomized controlled trials are needed to ascertain whether LED phototherapy may be more effective when increasing the spectral power, or in certain selected subpopulations.

Light-emitting diode phototherapy for unconjugated hyperbilirubinaemia in neonates

BACKGROUND

Phototherapy is the mainstay of treatment of neonatal hyperbilirubinaemia. The commonly used light sources for providing phototherapy are special blue fluorescent tubes, compact fluorescent tubes and halogen spotlights. However, light emitting diodes (LEDs) as light sources with high luminous intensity, narrow wavelength band and higher delivered irradiance could make phototherapy more efficacious than the conventional phototherapy units.

OBJECTIVES

To evaluate the effect of LED phototherapy as compared to conventional phototherapy in decreasing serum total bilirubin levels and duration of treatment in neonates with unconjugated hyperbilirubinaemia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2010, Issue 1), MEDLINE (1966 to April 30, 2010) and EMBASE (1988 to July 8, 2009). Handsearches of the proceedings of annual meetings of The European Society for Paediatric Research and The Society for Pediatric Research were conducted through 2010.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials were eligible for inclusion if they enrolled neonates (term and preterm) with unconjugated hyperbilirubinaemia and compared LED phototherapy with other light sources (fluorescent  tubes, compact fluorescent tubes, halogen spotlight; method of administration: conventional or fibreoptic).

DATA COLLECTION AND ANALYSIS

We used the standard methods of The Cochrane Collaboration and its Neonatal Review Group for data collection and analysis.

MAIN RESULTS

Six randomised controlled trials met the inclusion criteria for this review. Four studies compared LED and halogen light sources. Two studies compared LED and compact fluorescent light sources. The duration of phototherapy (six studies, 630 neonates) was comparable in LED and non-LED phototherapy groups (mean difference (hours) -0.43, 95% CI -1.91 to 1.05). The rate of decline of serum total bilirubin (STB) (four studies, 511 neonates) was also similar in the two groups (mean difference (mg/dL/hour) 0.01, 95% CI -0.02 to 0.04). Treatment failure, defined as the need of additional phototherapy or exchange blood transfusion (1 study, 272 neonates), was comparable (RR 1.83, 95% CI 0.47 to 7.17). Side effects of phototherapy such as hypothermia (RR 6.41, 95% CI 0.33 to 122.97), hyperthermia (RR 0.61, 95% CI 0.18 to 2.11) and skin rash (RR 1.83, 95% CI 0.17 to 19.96) were rare and occurred with similar frequency in the two groups.

AUTHORS' CONCLUSIONS

LED light source phototherapy is efficacious in bringing down levels of serum total bilirubin at rates that are similar to phototherapy with conventional (compact fluorescent lamp (CFL) or halogen) light sources. Further studies are warranted for evaluating efficacy of LED phototherapy in neonates with haemolytic jaundice or in the presence of severe hyperbilirubinaemia (STB ≥ 20 mg/dL).

The side effects of phototherapy for neonatal jaundice: what do we know? What should we do?

Neonatal phototherapy (NNPT), a noninvasive, easily available therapy, has been widely used for the treatment of neonatal jaundice for more than half a century. Its efficiency in decreasing plasma bilirubin concentration is well documented, and NNPT leads to greatly reduced exchange transfusion rates for neonates with hyperbilirubinemia. It is generally accepted that the side effects of NNPT are not serious and seem to be well controlled. This review will focus on these possible side effects as well as the approaches to minimize them.