Term Newborn Infants Research Articles

ABCs of base therapy in neonatology: role of acetate, bicarbonate, citrate and lactate.

Metabolic acidosis is common in preterm and term newborn infants and may be attributed to a variety of etiologies, potentially requiring base therapy such as acetate or bicarbonate. However, concerns exist regarding potential harm of sodium bicarbonate due to intracellular acidosis, fluctuations in cerebral blood flow, and osmolar load with rapid infusions, with no improvement in survival when used during resuscitation. Alternative approaches to correct metabolic acidosis include the addition of acetate in parenteral nutrition, intravenous lactated Ringer's (LR) solution, and use of oral citrate. Current guidelines focus on addressing the underlying cause of acidosis, reserving the use of sodium bicarbonate (NaHCO3) for severe cases requiring acute correction, LR instead of saline for volume boluses and using acetate or citrate for slow correction to stabilize acid-base status. Further research is necessary to better understand the efficacy and safety of acetate, NaHCO3, and other base sources in treating metabolic acidosis in neonates.

Continuous local anaesthetic wound infusion in infants undergoing thoracic or abdominal surgery: A systematic review

ObjectiveTo determine whether continuous local anaesthetic wound infusion (CLAWI) provides more effective pain relief and decrease the need for systemic opioids compared to other analgesic agents in term or preterm newborn infants undergoing thoracic or abdominal surgery. MethodsCochrane Central Register of Controlled Trials, Medline, Embase and CINAHL were searched from database inception to August 2022. Publications were screened and their references were hand-searched to identify additional studies. This review included randomized controlled trials (RCTs), quasi-RCTs, and cluster RCTs. Two reviewers independently extracted data and examined the methodological quality of the eligible studies. A meta-analysis was performed for available outcomes. ResultsAfter screening 1202 articles, two RCTs with 98 patients were included. Meta-analysis for combined data was possible for only two outcomes: pain scores post-surgery and length of hospital stay. The random effects model for the pooled standardised mean difference of pain scores between treatment groups post-surgery was -2.54 (95 % CI:7.53, 2.46, p = 0.3196) and for length of stay in the NICU was -0.19 (95 % CI:0.58, 0.21, p = 0.3574), suggesting that CLAWI was not more effective in either providing pain relief or reducing length of stay. However, the small number of studies included, the considerable heterogeneity between the studies, and the small sample sizes of the individual studies limit the generalizability of the findings. ConclusionThis review highlights the need for further, adequately powered well-designed, multicentre trials to examine the effectiveness of CLAWI in reducing postoperative pain in newborns undergoing abdominal and thoracic surgery. Level of evidenceLevel I - Evidence from a systematic review of all relevant randomized controlled trials

Ultra-high-frequency ultrasound (48-70 MHz) is a promising tool for improved gastrointestinal diagnostics in infants.

To investigate the clinical feasibility of ultra-high-frequency abdominal ultrasound (UHFUS) scans of preterm and term infants. Prospectively, 19 healthy term newborn infants were examined with conventional ultrasound (CUS) (Toshiba, Aplio i700, linear probe 14L5) and UHFUS (Visualsonics VevoMD, linear probes UHF48 and UHF70) according to a standardised protocol. Measurements of wall thickness were performed for; stomach, small intestine, colon and peritoneum. Five preterm infants, with or without suspected necrotising enterocolitis (NEC), were also examined with UHF48. Of these, only one was later diagnosed with NEC. Differences between CUS and UHFUS (UHF48) were found in measurements of thickness; for peritoneum 0.25 versus 0.13 mm (p < 0.001), small intestine 0.76 versus 0.64 mm (p = 0.039) and colon 0.7 versus 0.47 mm (p < 0.001) in healthy term infants. Gaining frequency from 46 to 71 MHz showed a mean reduction in measurements of peritoneum from 0.13 to 0.09 mm (p < 0.001). One preterm infant with NEC showed a fivefold and twofold increase in peritoneal and gastrointestinal wall thickness respectively, compared to healthy preterm infants. UHFUS was a clinically feasible, promising method with potential to improve gastrointestinal diagnostics in infants. Lower peritoneum thickness and gastrointestinal wall thickness were demonstrated with UHFUS compared to CUS, suggesting an overestimation by CUS.

The effect of phototherapy treatment on serum melatonin levels in term newborns.

The aim of this study was to investigate the effect of phototherapy treatment on serum melatonin levels in term newborn infants. This study was planned as a single-center, prospective, observational, case-control study. Term infants (gestation week ≥37 weeks) who received at least 6 h of phototherapy due to jaundice constitute the phototherapy group, while the term infants without jaundice and who were exclusively breastfed constitute the control group. Melatonin levels were examined by taking blood samples from babies in both groups at 02:00 at night. Melatonin values were compared between groups. The effect of phototherapy on serum melatonin levels was investigated. The relationship between the duration of phototherapy and maximum serum bilirubin values on melatonin values was investigated. Seventy term infants (64.3% girls) were included in the study. Mean gestational week was 38.3 ± 1.1 weeks, mean birth weight was 3295 ± 434 g. There was no statistically significant difference between the phototherapy group and the control group in terms of sex, type of delivery, gestational week, birth weight, height, and head circumference (all p > 0.05). Serum melatonin level was 20.3 ± 5.9 pg/mL (range: 8.7-36.6 pg/mL) in the phototherapy group and 19.9 ± 4.38 pg/mL (range: 9.9-26.3 pg/mL) in the control group. There was no significant difference between the two groups in terms of serum melatonin levels (p = 0.155). The mean total bilirubin value was 17.65 ± 1.48 mg/dL, and the average duration of phototherapy application was 13.94 ± 7.64 h in the babies in the phototherapy group. No correlation was found between the duration of phototherapy application and serum melatonin levels (p = 0.791). It was determined that there was no significant difference in serum melatonin levels in term newborn babies who received phototherapy for at least 6 h due to jaundice. No correlation was found between the duration of phototherapy application and the serum melatonin level of the maximum bilirubin values.

Reference ranges for SpO2, respiratory rate, and tidal volume in term newborn infants after birth: a narrative review

Celia Padilla-Sánchez, Susana Baixauli-Alacreu, Álvaro Solaz-García, Inmaculada Lara-Cantón, Anna Parra-Llorca, Máximo Vento

2023 American Heart Association and American Academy of Pediatrics Focused Update on Neonatal Resuscitation: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

This 2023 focused update to the neonatal resuscitation guidelines is based on 4 systematic reviews recently completed under the direction of the International Liaison Committee on Resuscitation Neonatal Life Support Task Force. Systematic reviewers and content experts from this task force performed comprehensive reviews of the scientific literature on umbilical cord management in preterm, late preterm, and term newborn infants, and the optimal devices and interfaces used for administering positive-pressure ventilation during resuscitation of newborn infants. These recommendations provide new guidance on the use of intact umbilical cord milking, device selection for administering positive-pressure ventilation, and an additional primary interface for administering positive-pressure ventilation.

Impact of cord clamping on haemodynamic transition in term newborn infants

ObjectiveTo assess the haemodynamic consequences of cord clamping (CC) in healthy term infants.DesignCohort study.SettingTertiary maternity hospital.Patients46 full-term vigorous infants born by caesarean section.InterventionsEchocardiography was performed before CC, immediately after CC...

2023 American Heart Association and American Academy of Pediatrics Focused Update on Neonatal Resuscitation: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

This 2023 focused update to the neonatal resuscitation guidelines is based on 4 systematic reviews recently completed under the direction of the International Liaison Committee on Resuscitation Neonatal Life Support Task Force. Systematic reviewers and content experts from this task force performed comprehensive reviews of the scientific literature on umbilical cord management in preterm, late preterm, and term newborn infants, and the optimal devices and interfaces used for administering positive-pressure ventilation during resuscitation of newborn infants. These recommendations provide new guidance on the use of intact umbilical cord milking, device selection for administering positive-pressure ventilation, and an additional primary interface for administering positive-pressure ventilation.

Respiratory patterns in spontaneously breathing near-term lambs delivered by caesarean section under spinal anaesthesia.

The transition to newborn life has typically been studied in intubated and mechanically ventilated newborn lambs delivered via caesarean section (CS) under general anaesthesia. As a result, little is known of the spontaneous breathing patterns in lambs at birth, particularly those at risk of developing respiratory distress (RD). We have developed a method for delivering spontaneously breathing near-term lambs to characterise their breathing patterns in the immediate newborn period. At 137-8 days gestation (2-3 days prior to delivery; term ∼147 days), fetal lambs (n = 7) were partially exteriorised for instrumentation (insertion of catheters and flow probes) before they were returned to the uterus. At 140 days, lambs were delivered via CS under light maternal sedation and spinal anaesthesia. Lambs were physically stimulated and when continuous breathing was established, the umbilical cord was clamped. Breathing patterns were assessed by measuring intrapleural and upper-tracheal pressures during the first four hours after birth. Newborn lambs display significant heterogeneity in respiratory patterns in the immediate newborn period that change with time after birth. Seven distinct breathing patterns were identified including: (i) quiet (tidal) breathing, (ii) breathing during active periods, (iii) breathing during oral feeding, (iv) tachypnoea, (v) expiratory braking manoeuvres, (vi) expiratory pauses or holding, and (vii) step changes in ventilation. We have described normal respiratory behaviour in newborn lambs, in order to identify respiratory behaviours that are indicative of RD in term newborn infants.

Evaluation of Mean “R” Wave Amplitude in Lead V1 of Electrocardiogram among Term Newborn Infants in Tertiary Care Institution in South India

Background: The changes in the left ventricle to right ventricle muscle mass ratio account for the majority of the age-related changes in pediatric electrocardiograms (ECGs). A newborn's right ventricle muscle mass is more than the newborn's left ventricle. Physiologically, newborn infants have a dominant right ventricle. Race differences in QRS voltage normal values exist. Compared to Euro-Americans, African-Americans have a higher upper normal limit of QRS voltages. Typically, right ventricular hypertrophy is seen in newborns. To distinguish between pathological and physiological newborn hypertrophy, it is critical to measure the mean QRS amplitude in healthy newborns. This is the first study on the Indian population, with previous ones being conducted among African-Americans. Methodology: Between 2015 and 2016, this prospective observational study was carried out in the pediatrics department of a tertiary care facility in India. The study included 76 term newborns who were under 3 days old. In Chennai's Kilpauk Medical College and Hospital, the newborn infants underwent clinical examinations as well as echocardiography before receiving their ECGs. A baseline questionnaire that had been previously created was used for data collection. Results: For the Indian population, the mean R wave amplitude was 11.56 mm, with a standard deviation of 2.96 mm, and the 5th and 95th percentiles were 6.85 mm and 16.15 mm, respectively. The Fridericia formula for the mean QTc interval gives a value of 357.14 ms, a standard deviation of 34.072 ms, and a 95% confidence interval of 349.36–364.93 ms. Since a newborn's heart rate typically exceeds 100 beats/min, the measurement of QTc using the Fridericia formula more accurately predicts QTc in the newborn. The mean heart rate was 125.75 beats/min, with a standard deviation of 15.44 beats/min, and the 5th and 95th percentiles were 93.7 and 149 beats/min, respectively. Conclusions: The “R” wave mean amplitude in lead V1 was 11.56 mm, with a 2.96 mm standard deviation; the fifth and ninety-fifth percentiles, respectively, were 6.85 mm and 16.15 mm. The population's “R” wave in the lead V1 exhibits racial differences in amplitude.

Characteristics and outcomes of respiratory distress among term infants born in a regional setting.

Respiratory distress is the leading cause of admission to neonatal units and is a common indication for medical retrieval. Whilst approximately 25% of births in NSW occur in regional centres, there is a paucity of neonatal research in these settings. To describe the characteristics and outcomes of term neonates admitted with respiratory distress to two regional special care nurseries (SCNs) and identify variables associated with the need for medical retrieval. We describe a cohort of 629 term infants admitted to the SCN in two regional hospitals, 2015-2019. We describe the admission characteristics, level of respiratory support, biochemical investigations, diagnosis and outcomes. During the study period, 629 eligible term infants were admitted, retrieval occurred in 29 (4.6%). Those admitted were more often male (66.5%), with a mean gestational age of 39 + 1 weeks (±9 days) and birth weight of 3470 g (±500 g). Infants requiring medical retrieval had higher PaCO2 on blood gas analysis (59.8 mmHg vs. 53.3 mmHg, OR 1.03, p = 0.02). There was no association between maternal GBS status, meconium-stained liquor, gestational age, or raised inflammatory markers and medical retrieval. Transient tachypnoea of the newborn was the most common diagnosis of neonates admitted to SCN with respiratory distress. Among term infants admitted to a SCN for respiratory distress most were male, of a normal birthweight and born in good condition. Within our cohort there was no association between retrieval and maternal GBS colonisation, meconium-stained liquor or raised infectious biomarkers. Medical retrieval was infrequent and was associated with higher PaCO2 on initial blood gas analysis. We present a large cohort of term newborn infants managed for respiratory distress in a regional setting over a five-year period. Retrieval was infrequent, and outcomes for the cohort were excellent with no deaths during the study period.

The need for neonatal jaundice screening awareness in the Pakistani population: short communication.

Neonatal jaundice is a common illness that affects around 80% of preterm and 50-60% of full-term newborn infants. It is one of the most common causes of neonatal death. Neonatal jaundice may be physiological or pathological. Physiologic jaundice is far more common than pathologic jaundice and accounts for most hyperbilirubinemia. Physiologic jaundice in neonates is due to greater hemoglobin breakdown compared to bilirubin clearance. While pathological jaundice occurs due to various infections, drug toxicity, inborn enzyme deficiencies, Rhesus fetal-maternal incompatibility, hypothyroidism, and congenital biliary duct obstruction diseases. In many parts of the world, midwives, and nurses perform spontaneous vaginal deliveries and they only rely on visual screening for neonatal jaundice. However, this is not reliable, especially for newborns having darker skin. Educating the mothers on screening for early detection of neonatal jaundice and seeking medical treatment in a country like Pakistan, which is considered a high-risk population, is crucial. Also, as most females give birth at home, hence, midwives' knowledge about neonatal jaundice also needs to be improved.

The use of transcutaneous bilirubin nomograms for the prevention of bilirubin neurotoxicity in the neonates.

Although neonatal jaundice is a ubiquitous and predominantly benign phenomenon, the risk of neurotoxicity exists in a number of infants with unconjugated hyperbilirubinemia. Plotting bilirubin values on nomograms enables clinicians to employ an anticipatory and individualized approach with the goal of avoiding excessive hyperbilirubinemia and preventing acute bilirubin encephalopathy and its progression to kernicterus. We aimed to construct nomograms for White term infants based on transcutaneous bilirubin (TcB) measurements using a JM-105 device. TcB measurements were taken in infants at ages ranging from 0 to 96 postnatal hours. We then constructed hour-specific TcB nomograms from forehead and sternum measurements in infants who did not require subsequent phototherapy. We included 2,981 TcB measurements taken on the forehead and 2,977 measurements taken on the sternum in 301 White term newborn infants. We assessed the predictive abilities of the nomograms at six postnatal time intervals using receiver operating characteristic curves. The areas under the curves indicated reasonable prediction of hyperbilirubinemia requiring phototherapy, except for the forehead measurement taken within the first 12 h of life. Sensitivity tended to rise as postnatal age increased. The nomograms illustrate dermal bilirubin dynamics in White term neonates during the first 4 days of life. They may be useful tools to predict individualized risk of hyperbilirubinemia requiring treatment, and to plan optimal follow-up of infants at risk of bilirubin neurotoxicity.

'She was hungry'-Croatian mothers' reasons for supplementing their healthy, term babies with formula during the birth hospitalisation.

To explore why Croatian mothers request formula for their healthy, term newborn infants during the postnatal hospital stay. Four focus groups discussions were conducted with a total of 25 women who gave birth to healthy newborn infants, between May and June 2021 in Split, Croatia. A homogenous, non-random purposive sampling technique was used. The semi-structured interview schedule contained 15 open-ended questions. Reflexive thematic analysis was applied. Three themes were generated. The first theme fear of hunger referred to the mothers' fears arising from difficulties in interpreting newborn infant behaviour and finding solace in giving formula. The second theme too little support-too late reflected participants' unrealised expectations of hospital staff. The third theme non-supportive communication addressed mother's need for empathy during the postpartum hospital stay. Croatian mothers want to breastfeed, but often feel unsupported in doing so in the maternity hospital setting. Antenatal education of expectant mothers and training of maternity staff in breastfeeding counselling, with a strong emphasis on communication skills, as well as employment of International Board Certified Lactation Consultants and/or volunteer breastfeeding counsellors, were perceived by participants as a way to decrease mothers' requests for formula for their healthy, newborn infants.

Incomplete Exhalation during Resuscitation-Theoretical Review and Examples from Ventilation of Newborn Term Infants.

Newborn resuscitation guidelines recommend positive pressure ventilation (PPV) for newborns who do not establish effective spontaneous breathing after birth. T-piece resuscitator systems are commonly used in high-resource settings and can additionally provide positive end-expiratory pressure (PEEP). Short expiratory time, high resistance, rapid dynamic changes in lung compliance and large tidal volumes increase the possibility of incomplete exhalation. Previous publications indicate that this may occur during newborn resuscitation. Our aim was to study examples of incomplete exhalations in term newborn resuscitation and discuss these against the theoretical background. Examples of flow and pressure data from respiratory function monitors (RFM) were selected from 129 term newborns who received PPV using a T-piece resuscitator. RFM data were not presented to the user during resuscitation. Examples of incomplete exhalation with higher-than-set PEEP-levels were present in the recordings with visual correlation to factors affecting time needed to complete exhalation. Incomplete exhalation and the relationship to expiratory time constants have been well described theoretically. We documented examples of incomplete exhalations with increased PEEP-levels during resuscitation of term newborns. We conclude that RFM data from resuscitations can be reviewed for this purpose and that incomplete exhalations should be further explored, as the clinical benefit or risk of harm are not known.

Transcutaneous bilirubinometry versus total serum bilirubin measurement for newborns.

Jaundice is a very common condition in newborns, affecting up to 60% of term newborns and 80% of preterm newborns in the first week of life. Jaundice is caused by increased bilirubin in the blood from the breakdown of red blood cells. The gold standard for measuring bilirubin levels is obtaining a blood sample and processing it in a laboratory. However, noninvasive transcutaneous bilirubin (TcB) measurement devices are widely available and used in many settings to estimate total serum bilirubin (TSB) levels. To determine the diagnostic accuracy of transcutaneous bilirubin measurementfor detecting hyperbilirubinaemia in newborns. We searched CENTRAL, MEDLINE, Embase, CINAHL and trial registries up to 18 August 2022. We also checked the reference lists of all included studies and relevant systematic reviews for other potentially eligible studies. We included cross-sectional and prospective cohort studies that evaluated the accuracy of any TcB device compared to TSB measurement in term or preterm newborn infants (0 to 28 days postnatal age). All included studies provided sufficient data and information to create a 2 × 2 table for the calculation of measures of diagnostic accuracy, including sensitivities and specificities. We excluded studies that only reported correlation coefficients. Two review authors independently applied the eligibility criteria to all citations from the search and extracted data from the included studies using a standard data extraction form. We summarised the available results narratively and, where possible, we combined study data in a meta-analysis. We included 23 studies, involving 5058 participants. All studies had low risk of bias as measured by the QUADAS 2 tool. The studies were conducted in different countries and settings, included newborns of different gestational and postnatal ages, compared various TcB devices (including the JM 101, JM 102, JM 103, BiliChek, Bilitest and JH20-1C) and used different cutoff values for a positive result. In most studies, the TcB measurement was taken from the forehead, sternum, or both. The sensitivity of various TcB cutoff values to detect significant hyperbilirubinaemia ranged from 74% to 100%, and specificity ranged from 18% to 89%. The high sensitivity of TcB to detect hyperbilirubinaemia suggests that TcB devices are reliable screening tests for ruling out hyperbilirubinaemia in newborn infants. Positive test results would require confirmation through serum bilirubin measurement.

Croatian mothers were 11 times more likely to give their newborn infants formula in hospital if they had used it for their older children.

We determined the prevalence and predictors of formula supplementation for healthy, term newborn infants in hospital. A cross-sectional study was conducted from 1 June to 21 October 2020 among Croatian women who gave birth to healthy newborn infants of ≥37 weeks gestation and birth weight of ≥2500 g at the University Hospital of Split, Croatia. The mothers completed a questionnaire on hospital infant feeding practices and breastfeeding self-efficacy. Multinomial logistic regression investigated associations between perinatal factors and formula supplementation. We approached 392 mothers, and 355 (90.6%) were included: 286 (80.6%) said their newborn infant received formula in hospital and it was at their request in 173/286 (60.5%) of cases. The adjusted analyses identified factors associated with increased odd ratios (OR) and 95% confidence intervals (CI) for formula supplementation: no previous breastfeeding experience (OR 9.42, 95% CI 3.51-25.28), breastfeeding difficulties in hospital (OR 9.12, 95% CI 3.46-24.09) and older children who received formula during their birth hospitalisation (OR 11.51, 95% CI 4.4-30.1). Mothers were not routinely notified of the risks. An unacceptably high proportion of healthy newborn infants received formula in hospital.

The effect of cord clamping time on cord blood gas in term newborn babies delivered by cesarean section

Objective: Umbilical cord clamping time is a situation that should be planned before delivery. It is recommended that the umbilical cord be clamped for at least 30–60 seconds after birth in healthy preterm and term newborns. There are few studies investigating the effect of umbilical cord clamping time on cord blood gas. If the umbilical cord is clamped before 30 seconds after birth, it is considered early clamping, and if it is clamped after 30 seconds, it is considered late clamping. In this study, we aimed to compare the early or late clamping time of the umbilical cord with the acid-base parameters and lactate values of babies. Methods: A total of 217 term newborn infants who were delivered by cesarean section between December 2020 and December 2021 in our hospital, whose umbilical cord clamping times were recorded and who had cord blood samples, were included in our study retrospectively. pH, pCO2, pO2, HCO3, BE, lactate, Hb and bilirubin values in cord blood gas samples were compared between the two groups. Results: Two hundred seventeen term newborn babies were included in the study. Cord clamping time of infants was delayed in 125 (57.6%) and early in 92 (42.4%) infants. The mean pH in cord blood gas was 7.37±0.07 (7.16–7.57), pCO2 was 39.73 ±8.97 (20.3–65.4) mmHg, pO2 was 53.42±41.95 (14.8–198) mmHg, BE was -2.18±2.90 (-11.9–13.6) mmol/L, lactate was 2.12±0.88 (0.50–5.90) mmol/L, Hb was 14.57± 2.54 (10–23.7) g/dl, and bilirubin was 1.71±1.33 (0–3.7) mg/dl. Conclusion: There was no significant relationship between early and late clamping of the umbilical cord and acid-base parameters, and hemoglobin values in cord blood gas in term newborn babies delivered by cesarean section.

Serotonin and cyclic sleep organization in full-term newborn infants with intrauterine growth retardation

BACKGROUND: The high frequency of neurological and mental diseases in children who had intrauterine retardatiojn development indicates the need to study specific markers of disorders of fetal brain functional development, in particular, the state of the serotonergic system, which plays a key role in the morpho-functional development of the brain in early ontogenesis.&#x0D; AIM: To study the content of serotonin in full-term newborns with intrauterine development delay in comparison with quantitative and qualitative characteristics of sleep.&#x0D; MATERIALS AND MЕTHODS: The main group consisted of 26 newborns, whose intrauterine development took place in conditions of chronic placental insufficiency, which led to the formation of an asymmetric form of intrauterine retardatiojn development. The control group consisted of 72 healthy newborns from healthy mothers without pregnancy complications. Children of each group are divided into three subgroups depending on gestational age: I 37, II 38, III 3940 weeks. In all children, 712 hours after birth, an electropoligram of sleep was recorded (an electroencephalograph of the company Mizar, Russia) and its quantitative and qualitative analyses were carried out, highlighting the orthodox, paradoxical phase and undifferentiated state. The serotonin content was determined in platelet-rich plasma of blood from the umbilical cord vein after birth, as well as in a platelet suspension prepared from venous blood taken on the first day of life. The content of serotonin in platelets was judged by the indicator obtained by dividing the amount of serotonin in the platelet suspension by the platelet level. The amount of serotonin was determined by high-performance liquid chromatography with electrochemical detection. Statistical analysis was performed using the Statistica 6 program (Statsoft Inc, USA).&#x0D; RESULTS: We report here a low content of serotonin in platelet-rich plasma and platelets of newborns with intrauterine growth retardation and the absence of its normal increase in weeks 3739 of intrauterine development, as well as a violation of the genetic programming for the sleep-wake cycle organization.&#x0D; CONCLUSIONS: Assessment of the serotonin-producing system of the brain in comparison with the newborn sleep pattern can serve as a diagnostic marker of brain damage and substantiate the need for timely application of neuroprotection.

The gestational age significantly affects peripheral perfusion index value in low-altitude areas.

The gestational age significantly affects peripheral perfusion index value in low-altitude areas.