Melatonin levels during the first week of life and their relation with the antioxidant response in the perinatal period

AIM

Melatonin is a potent free radical scavenger and an indirect antioxidant. Knowledge about the behavior of melatonin secretion in the early neonatal period, which may relate to its properties at a vital stage during very high antioxidant demands, is limited.

PATIENTS AND METHODS

We studied 35 newborns admitted to the Neonatal Unit with respiratory distress syndrome (RDS) and with no signs of sepsis, severe anemia, hemodynamic compromise or malformation. The gestational age of the newborns was 26-40 weeks (mean value 32.5 weeks) and the weight at birth was 870-4,400 g (mean value 1,800 g). They were classified into two groups: <or=1,500 g or >1,500 g birthweight. In all cases, at 09:00 h on their 1st, 3rd and 7th days of life, serum melatonin was measured by RIA. The clinical history was recorded and treatment and follow-up were performed according to established neonatology practice, and the resultant data recorded. Informed consent from the parents or guardians was obtained in accordance with the Declaration of Helsinki. Statistical analysis was carried out using ANOVA-II (factor I: day of sample; factor II: birthweight).

RESULTS

There were significant increases in melatonin levels with increasing birthweight (p = 0.017), but no changes by day of sample. Although in both study groups melatonin levels increased during the first few days this was not statistically significant.

CONCLUSIONS

In newborns of low birthweight, we report high melatonin concentrations in the morning and during the first week of life. These increase with maturation, and at full-term were similar to nocturnal levels during the acrophase of pineal gland secretion in toddlers and schoolage children, when pineal gland secretion is maximal and takes place reflecting environmental variations. In the early neonatal period these high levels of melatonin seem to derive from extrapineal sources, which mature to provide antioxidant protection in accordance with other elements of the antioxidant network to compensate for the high levels of oxidative stress that are present in the perinatal period.

Iodine intake and prevalence of thyroid autoimmunity and autoimmune thyroiditis in children and adolescents aged between 1 and 16 years

OBJECTIVES

To determine the status of iodine nutrition in children and adolescents in Almería, Spain. To calculate prevalence of thyroid autoimmunity (TA) and autoimmune thyroiditis (AT) in pediatric ages and to research into associated factors.

METHODS

Cross-sectional epidemiological study. By a multistage probability sampling 1387 children and adolescents aged between 1 and 16 were selected. Physical examination was carried out including neck palpation. Parents were asked about eating habits as well as about social and demographic aspects. Urinary iodine, free thyroxine, TSH, antiperoxidase and antithyroglobulin antibodies were measured. TA was diagnosed when any antibody was positive and AT when autoimmunity was associated with impaired thyroid function or goitre. Results are shown using percentages (and its 95% confidence interval). To study associated factors we used multiple logistic regression, quantifying the relation with odds ratio (OR), and multiple lineal regression.

RESULTS

Median urinary iodine concentration was 199.5 μg/l. The prevalences of TA and AT were 3.7% (2.4-5.0) and 1.4% (0.4-2.4). TA is associated with female sex (OR 2.78; P<0.001) and age (OR 1.30; P<0.001). Iodine status is associated with the intake of milk and dairy product (P<0.001) and vegetable (P=0.021) but not with use of iodized salt at home (P=0.1).

CONCLUSIONS

The iodine supply in children and adolescents in our city is optimal. Milk and dairy products are the most important iodine sources. TA and AT are prevalent in pediatric ages in our city mainly in females and older subjects.

Prevalence and factors linked to allergic rhinitis in 10 and 11-year-old children in Almería. Isaac Phase II, Spain

BACKGROUND

Allergic rhinitis affects 10-30% of children in developed countries and has increased in frequency over the last few decades, probably due to changes in the environment and life style.

AIM

To assess the prevalence, severity, and factors linked to rhinitis in 10 and 11-year-old children from Almeria (Spain).

METHODS

As part of ISAAC II, a cross-sectional survey was conducted among a representative sample of 1143 schoolchildren in spring and autumn of 2001, using homologated questionnaires and skin-prick testing.

RESULTS

The overall prevalence of rhinitis and rhinoconjunctivitis were 38.9% and 24.8%, respectively, 17.9% had medically diagnosed rhinitis. During the previous year symptoms disturbed daily activities and school attendance in some measure in 40% and 26% of children with rhinitis, respectively. The risk factors found in the multiple logistic regression analysis were atopy (OR 2.57; 95% CI 1.92-3.42); cat contact at home during first year of life (OR 2.4 95% CI 1.13-5.12); prior medical diagnosis of asthma (OR 2.2; 95% CI 1.22-4.02); nocturnal cough in absence of colds (OR 1.9; 95% CI 1.25-2.97); diagnosis of rhinitis in one of the parents (OR 1.8; 95% CI 1.31-2.59); wheezing at any time (OR 1.6; 95% CI 1.18-2.28); and nursery school attendance (OR 1.5; 95% CI 1.21-2.5).

CONCLUSIONS

The prevalence of rhinitis found is superior to that of other centres participating in the ISAAC Phases I and II, and coexists with asthma and eczema in many children. The independent risk factors associated to rhinitis are in accordance with previous reports.

Thyroid Function and Thyroid Autoimmunity in Relation to Weight Status and Cardiovascular Risk Factors in Children and Adolescents: A Population-Based Study

OBJECTIVE

In obese subjects, slight increases have been observed in thyrotropin [thyroid-stimulating hormone (TSH)] levels, but data in children are scarce. The aim of this study was to evaluate whether thyroid function and autoimmunity vary with weight status in a healthy population of children and adolescents and to determine whether hyperthyrotropinemia is associated with any cardiovascular risk factor.

METHODS

This cross-sectional epidemiological study was conducted in Almería (Spain) on a representative sample of 1317 healthy subjects aged 2-16 years. Thyroid function, thyroid autoimmunity and cardiovascular risk factors were measured. Chi-square test, analysis of variance and multiple linear regression were used in the statistical analyses.

RESULTS

The obese children and adolescents had thyrotropin levels (mean ± standard deviation) of 3.12±2.44 mU/L. These levels were higher than those of overweight subjects (2.79±1.51 mU/L) and of normal weight subjects (2.73±1.30 mU/L) (p=0.02). Levels of free thyroxine and urinary iodine did not differ significantly between the groups. The prevalence (95% confidence interval) of thyroid autoimmunity was lower in the individuals with normal weight (2.9%; 2.0-4.2) than in the overweight (6.3%; 3.9-9.9) and obese subjects (5.6%, 2.5-11.3) (p=0.02). TSH levels were associated with obesity (β=0.36; p<0.001) and thyroid autoimmunity (β=1.10; p<0.001). They were not associated with any cardiovascular risk factor.

CONCLUSION

Obese children and adolescents had higher levels of thyrotropin than those who were overweight and of normal weight. The differences among the groups were of very little clinical significance and could possibly be linked to the higher prevalence of thyroid autoimmunity in obese subjects. The hyperthyrotropinemia in these subjects was not associated with any cardiovascular risk factor.

Prevalence and factors linked to atopy in 10-and 11-year-old children in Almería, Spain

BACKGROUND

During the last decades there has been an increase in both allergic diseases and allergic sensitisation, probably due to changes in the environment and living habits. ISAAC Phase II was designed to establish the prevalence and associated factors to asthma and allergic disorders in childhood.

AIM

To assess the prevalence and factors linked to atopy in 10-11 year-old children from Almería (Spain).

METHODS

As a part of ISAAC II, a survey was conducted among a sample of 1143 schoolchildren using standardised questionnaires and skin-prick testing.

RESULTS

The overall prevalence of atopy was 42.5%. Most common sensitisations were to Dermatophagoides pteronyssinus (36.2%), D. farinae (32.3%), cat (10.8%), Alternaria (7%), grass (6%), and tree pollen (1.7%). 34.9% of these sensitisations could be regarded as subclinical sensitisations. The fractions of asthma, rhinitis and eczema attributable to atopy were 49.2%, 40.4% y 18.6%, respectively. After multivariate analysis, the risk of atopy was significantly lower among females (OR 0.62, CI 95% 0.45-0.86); children with older siblings (OR 0.67; CI 95% 0.49-0.92); intestinal parasites (OR 0.68; CI 95% 0.48-0.97); contact with farm animals in the past (OR 0.48 CI 95% 0.23-0.99); or other animals at present (OR 0.53 CI 95% 0.30-0.95). To have an allergic father (OR 2.96 CI 95% 1.77-4.94) was the only significant risk factor.

CONCLUSIONS

We found several independent factors which significantly protect against atopic sensitisation. These protective factors were not the same for asthma, rhinitis or eczema, suggesting that other factors could interact to influence atopy and act against such protective factors.

Reference Values of Reticulocyte Hemoglobin Content and Their Relation With Other Indicators of Iron Status in Healthy Children

Reticulocyte hemoglobin content (CHr) is considered an indicator of functional iron deficiency, but is understudied in children. The goals of this study are to determine the reference intervals for CHr in healthy children, and their relation with iron parameters, erythropoiesis, and individual conditions. A total of 902 children without iron deficiency, aged 1 to 11 years were analyzed in a cross-sectional study. Besides a physical examination of the subjects and a questionnaire completed by their parents, the complete blood count, serum transferrin receptor, ferritin, transferrin saturation, erythrocyte protoporphyrin, serum erythropoietin, C-reactive protein, and CHr levels were measured. Changes in CHr, iron status, and erythropoiesis at different age intervals were analyzed and linear multiple regression was used to identify the factors that determine CHr variability. Mean value obtained for CHr was 30.9±1.8 pg (P2.5-P97.5: 26.9 to 34.3 pg), but the influence of age on CHr (the values increased with age) and on the iron parameters justified the establishment of different reference ranges. In addition to age, nutritional status, hematologic measurements, reticulocytes, transferrin saturation, and erythrocyte protoporphyrin accounted for 39% of CHr variability.

The influence of maternal erythrocyte deformability on fetal growth, gestational age and birthweight

The increase in blood viscosity during pregnancy reduces maternal-fetal blood flow, which can lead to fetal hypoxia and acidosis. These factors have been related to a reduction in fetal growth and to premature births. We carried out a longitudinal study of 36 normal-term gestations at different stages of the pregnancy. We analyzed the erythocyte deformability, the intraerythocyte viscosity and the plasma viscosity in the mother, as well as the relation of these parameters to fetal growth (biparietral diameter (BPD) and length of the femur), birthweight, gestational age at birth and the Agpar score. The results obtained were as follows: from weeks 25 to 36 of pregnancy (30.9 (SD 2 weeks)) there occurs a significant increase in maternal erythocyte rigidity (p < 0.05) (despite the compensatory decrease in intracellular viscosity). This increase is very significantly related to the fetal biparietral diameter (r = -0.50, p < 0.01), the length of the fetal femur (r = -0.48, p < 0.02), gestational age at birth (r = -0.73, p < 0.0001, birthweight (r = -0.63, p < 0.001) and the Agpar score 5 minutes after birth (r = 0.67, p < 0.001). Our conclusions are that the reduction in erythocyte deformability (which we attribute to alterations in the fluidity or elasticity of its membrane) and the factors that increase the aggregation capacity of the red cells (modulators of blood viscosity and of blood flow in the placental intervillous space) are risk factors for reduced fetal growth, lower birthweight and lower gestational age at birth. By avoiding maternal hematocrit levels higher than 36% we could improve uteroplacental perfusion, fetal growth and perinatal results.

Changes in erythrocytic deformability and plasma viscosity in neonatal ictericia

We studied 45 full-term newborns divided into 3 groups. Group 1: 17 newborns with bilirubin <10 mg/dL; Group 2: 18 newborns with hemolytic ictericia (bilirubin 11-20 mg/dL) and Group 3: 10 newborns with moderate hemolytic ictericia needing exchange transfusion. The following were studied: erythrocytic deformability, plasma viscosity, plasmatic osmolarity, seric bilirubin, bilirubin/albumin ratio, free fatty acids and corpuscular volume of the erythrocytes. In full-term newborns, the following are risk factors for increased erythrocytic rigidity: neonatal hemolytic illness (p = 0.004, odds ratio: 7.02), increases in total bilirubin (p = 0.02, odds ratio: 4.3) and increases in the bilirubin/albumin ratio (p = 0.025, odds ratio: 4.25). Furthermore, the most important risk factor for high plasma viscosity is also neonatal hemolytic illness (p = 0.01, odds ratio: 2.30). The role of total bilirubin is also important (p = 0.09, odds ratio: 2.10), while that of the bilirubin/albumin ratio (p = 0.012, NS) is less so. The greater the hemolysis, the greater the erythrocytic rigidity and plasma viscosity (p < 0.01). In full-term newborns with moderate ictericia, hemolytic illness and increases in the bilirubin/albumin ratio are accompanied by rheological alterations that could affect cerebral microcirculation and cause a neurological deficit not exclusively related to the levels of bilirubin in plasma.

PREVALENCE OF METABOLIC SYNDROME AMONG ADOLESCENTS IN A CITY IN THE MEDITERRANEAN AREA: COMPARISON OF TWO DEFINITIONS

BACKGROUND AND OBJECTIVE

there are few studies on the prevalence of metabolic syndrome (MetS) in European adolescent populations, and some have reported a higher prevalence in the Mediterranean basin area. Our objective was to examine the prevalence of MetS in adolescents in a Mediterranean city of Spain, comparing two different definitions of MetS and the associated risk factors.

METHODS AND RESULTS

a cross-sectional population-based study was conducted among 379 adolescents aged 12-16.9 years, selected using a random sampling method. Anthropometric measurements and fasting blood samples were obtained. The definitions of MetS used were that of the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATPIII) and that of the International Diabetes Federation (IDF). Kappa coefficient was used to measure the agreement between definitions and a multivariate logistic regression model to determine the associated risk factors.

RESULTS

the prevalence of MetS was 5.7% (95%CI 3.33-8.07) according to the NCEP-ATPIII definition and 3.8% (95%CI 1.85-5.75) according to the IDF definition. No differences between the sexes or by age groups were found. The agreement between the two definitions was very good (kappa 0.815), especially in the obese subsample, but was lower in normal weight adolescents (kappa 0.497). Insulin resistance and obesity were associated with both definitions.

CONCLUSIONS

the prevalence of MetS in our adolescent population is higher than the European media. Although the overall agreement between both definitions was very good, the prevalence was higher using the NCEP-ATPIII criteria. Independently of the definition used, obesity and insulin resistance were risk factors for MetS.

Status of folate in healthy children in Almeria

The objective of this study is to establish reference values for folic acid in a healthy population of children aged 4-11 years and to examine related epidemiological, dietary and analytical factors. A cross-sectional study of 658 healthy children aged 4-11 years was made. Epidemiological, socioeconomic and dietary variables were analysed, the BMI Z-score was obtained, levels of serum folate and serum vitamin B₁₂ were determined and haematological, iron status and erythropoietic activity parameters were examined. The study data were analysed by non-parametric tests and linear multiple regression. The mean folate value was 8.6 ± 4.6 ng/mL (95% reference interval: 2.8-20 ng/mL). A level < 3 ng/mL (5th percentile) was considered as folate deficiency (4.6% of subjects). No child reported symptoms related to this deficiency. Folate values were significantly lower with age (p < 0.01), low NSE and low parental educational level (p: 0.0001). No relationship was found between folates and the analytical variables. According to multivariate linear regression, the variables significantly associated with serum folate were age, socioeconomic level and vitamin B₁₂.Conclusions: Serum folate levels in healthy school children are described. Age, socioeconomic level and serum vitamin B₁₂ are factors associated with folate status. Specific cut-off values for a paediatric population should be defined. What is Known: • Folic acid is an essential micronutrient for optimal growth and development; its deficit is associated with adverse health effects. • The studies on their status and deficit are not comparable due to a lack of agreement on appropriate indicators and reference values. What is New: • This study reports the levels of serum folate in a large population of healthy schoolchildren, with strict inclusion criteria in a developed country and identifies the associated sociodemographic, dietary and analytical (vitamin B12, iron parameters and erythropoietic activity) factors, avoiding potential confusion.

Monitoring the incidence, duration and distribution of hyperglycaemia in very-low-birth-weight newborns and identifying associated factors

Objectives Hyperglycaemia is a common metabolic disorder in very-low-birth-weight (VLBW) infants and is associated with increased morbidity and mortality. The objective is to describe the incidence, duration, episodes and distribution of hyperglycaemia during the first 7 days of life of VLBW infants. Methods This is a prospective cohort study of 60 newborns weighing <1,500 g. Blood glucose levels were monitored with a continuous glucose monitoring system (CGMS) during the first 7 days of life. Hyperglycaemia was defined as glucose ≥180 mg/dL (≥10 mmol/L). Results Incidence of hyperglycaemia recorded with the CGMS was 36.6% (95%CI: 24.6-50.1). In almost 74.6±5.48% of these cases the duration of the episode exceeded 30 min and in 45.25% (95%CI: 2.26-57.82) it exceeded 2 h. The condition occurred most frequently during the first 72 h of life. One-fifth of cases were not detected with scheduled capillary tests and 84.6% of these had hyperglycaemic episode durations of 30 min or more. Agreement between the two techniques was very good (r=0.90, p<0.001) and the CGMS proved to be reliable, accurate and safe. Hyperglycaemia detected by a CGMS is associated with lower gestational age (OR: 0.66, p=0.002), lower birth weight (OR: 0.99, p=0.003), the use of ionotropic drugs (OR: 11.07, p=0.005) and death (OR: 10.59, p=0.03), and is more frequent in preterm infants with sepsis (OR: 2.73, p=0.1). No other association was observed. Conclusions A CGMS could be useful during the first week of life in VLBW infants due to the high incidence and significant duration of hyperglycaemia and the high proportion of cases that remain undetected. The advantage of the CGMS is that it is able to detect hyperglycaemic episodes that the capillary test does not.

Melatonin and beta-endorphin changes in children sensitized to olive and grass pollen after treatment with specific immunotherapy

BACKGROUND

Specific immunotherapy for respiratory allergy, a seasonal disease, significantly reduces the inflammatory process, attenuating the clinical symptoms. The mechanism for the clinical beneficial effect of immunotherapy has not yet been clarified. Melatonin shows a circadian and seasonal variation and together with the endogenous opioid system plays an immunomodulatory role acting on both specific and nonspecific immunity responses. Thus, the possibility that immunotherapy involved changes in the melatonin-opioid system was investigated.

METHODS

Thirty-five children aged 3-15 years with rhinitis and asthma due to olive + grass pollen sensitization were studied. The patients were treated with depot extracts containing the identified allergens with increasing doses from 1 to 1,000 IU/ml during 3 months. Melatonin, beta-endorphin, total and specific IgE and IgG4 were determined before and after treatment.

RESULTS

All children showed a significant improvement of their symptoms at the end of the treatment, coinciding with a significant drop of both melatonin and beta-endorphin levels. Total IgE decreased in most of the cases although the mean values did not show significant changes. Specific IgE and IgG4 were also unchanged. A significant correlation between melatonin and beta-endorphin and between beta-endorphin and IgG4 was found before immunotherapy, and these correlations disappeared when the treatment was finished.

CONCLUSIONS

The decrease in the levels of melatonin and beta-endorphin suggests the disappearance of their stimulating influence on the immune system. Thus, hyposensitization after immunotherapy may involve, at least in part, the inhibition of the immunoenhancing properties of the melatonin-opioid system.

Users evaluation of a Spanish eHealth pediatric website

BACKGROUND

Parents use the Internet to take decisions about their children's health, but few resources have focused on eHealth technology evaluations from their point of view.

OBJECTIVE

The main aim of this research was to evaluate a Spanish eHealth pediatric website for parents.

METHODS

A previously validated web questionnaire was used to evaluate five domains: usability, utility, trust and confidence, well-child section and accessibility of the website. Univariate, bivariate and multiple linear regression analyses were performed.

RESULTS

516 users participated in the research and rated the website as usable, useful, trustworthy and accessible. Higher scores were given by the participants who relied most on the Internet for taking decisions about health; by the participants who used a smartphone to access the pediatric website; by the participants who knew the website the longest; and by the participants who had accessed it more times. No differences in the evaluations of the website were found regarding age, education level or household income of the participants.

CONCLUSIONS

eHealth pediatric websites, written by a pediatrician in an easy to understand language, can be perceived as usable, trustworthy, useful and accessible by their users and consequently help them with their decisions making. Some characteristics of the users are associated with a better perception of these websites.

[Insulin glargine in intensively-treated type 1 diabetes mellitus]

OBJECTIVES

To evaluate the use of insulin glargine in intensively-treated children and adolescents. To assess the degree of patient and parent satisfaction with this treatment.

PATIENTS AND METHODS

We studied 42 patients with type 1 diabetes. There were 27 girls and 15 boys. The mean age at diagnosis was 6.8 years (range 1.2-13.2), the mean age at initiation of glargine therapy was 12.8 years (range 7.0-17.7), and the mean duration of diabetes was 6.1 years (range 2.0-11.9). Glargine indications were poor metabolic control or frequent hypoglycemia with multiple daily injections of NPH insulin, which were substituted by one dose of glargine. Patient and parent satisfaction with diabetes treatment was assessed with the scale published by Boot. ANOVA, Student's t test, Mann-Whitney and Fisher tests were applied.

RESULTS

Variables are reported as mean 6 standard deviation. After 18 months, glargine reduced hemoglobin A1c levels (7.65 % +/- 0.74 vs. 8.03 % +/- 0.69; p = 0.001), with no significant changes in insulin dose (1.03 +/- 0.19 U/kg/day vs. 1.08 +/- 0.21; p = 0.052) or body mass index SDS (standard deviation score) (+0.51 +/- 0.96 vs. 10.61 +/- 1.02; p = 0.11). Glargine also increased patient satisfaction (+44.5 +/- 18.8 points vs. -9.9 +/- 26.8; p < 0.001) and parent satisfaction (+42.0 +/- 17.9 points vs. -20.8 +/- 29.1; p < 0.001) with diabetes treatment.

CONCLUSIONS

1. Glargine insulin improves metabolic control in intensively-treated children and adolescents with type 1 diabetes. 2. Glargine also improves patient and parent satisfaction with diabetes treatment.

Mapping the Field in Stress, Anxiety, and Postpartum Depression in Mothers of Preterm Infants in Neonatal Intensive Care

Objective: The main aim of this study was to describe and conduct a bibliometric analysis of the state of research on stress, anxiety, and postpartum depression in mothers of preterm infants in the Neonatal Intensive Care Unit. Background: Women affected by premature births are particularly exposed to mental health difficulties in the postpartum period. The desire to comprehend and the growing interest in research on stress, anxiety, and postpartum depression in mothers of preterm infants in neonatal intensive care have led to a substantial rise in the number of documents in this field over the last years. Thus, it makes it vital to regularly review the state of knowledge on this phenomenon in order to identify progress and constraints, to stimulate reflection, and to encourage progress in future research. Method: This study examined 366 articles published in the Scopus database (1976–2020). Keyword analysis was also used to identify hot research trends to be developed in future studies. This study complies with the PRISMA-Scr guidelines for quality improvement research in the EQUATOR network. Results: Our results reveal that research in this field is in a period of high production and allows this flourishing body of work to be organized into different periods, highlighting the most important themes. In such a way, our research enriches the lively field by presenting a comprehensive understanding of the field. Discussion: The key contribution of this study is the development of a conceptual map of research on stress, anxiety, and postpartum depression in mothers of preterm infants in neonatal intensive care units.

Impact of breastfeeding on ICU admissions and need for mechanical ventilation in infants younger than 6 months with RSV+ bronchiolitis. An observational study

INTRODUCTION

This work aimed to analyze whether breastfeeding is a predictive factor for admission to ICU or needing mechanical ventilation in children under 6 months with RSV+ respiratory infection.

METHODS

A retrospective cohort study was performed in three hospitals. Binary and multiple logistic regression analyses were performed to evaluate the association of variables with admission to the ICU or receiving mechanical ventilation.

RESULTS

We analyzed 414 admissions, of which 293 (70.8%) had received breastfeeding, 43 (8.1%) were admitted to the ICU, and 26 (5.4%) required mechanical ventilation. Bivariate analysis showed that breastfeeding for at least 15 days and a longer duration of breastfeeding were associated with a lower risk of admission to the ICU and requiring mechanical ventilation. Multivariate analysis showed that not having been breastfed for at least 1 month was predictive of ICU admission; not having been breastfed for at least 2 months was predictive of needing mechanical ventilation.

CONCLUSIONS

Breastfeeding for as little as 15-28 days could be associated with a lower risk of ICU admission and requiring mechanical ventilation in infants younger than 6 months admitted for RSV+ bronchiolitis. Since breastfeeding is one of the few protective factors that can be promoted, this finding is relevant for current clinical practice and the development of health promotion programs. Future studies can compare their results to ours.

Classification of very low birth weight infants as small for gestational age: International vs. national standards

BACKGROUND

It is not precisely known whether the use of national (Carrascosa 2008) and international growth standards (INTERGROWTH-21) shows good concordance in classifying very low birth weight infants as small-for-gestational-age or whether with the same degree of morbidity and mortality. The aims of this study were a) to evaluate the concordance between small-for-gestational-age neonates weighing <1500 g classified using the national and international standards, and b) to compare the morbidity and mortality of small-for-gestational-age neonates classified by both standards.

METHODS

A retrospective cohort study was conducted with very low birth weight infants. The concordance between the INTERGROWTH-21 and Carrascosa 2008 standards was analyzed, along with differences in gestational age, weight, medical requirements, morbidity, and mortality, among small-for-gestational-age neonates classified by both standards. Small-for-gestational-age was defined as a birth weight z score ≤ -1.28.

RESULTS

A total of 250 neonates weighing <1500 g, who were born between 26 and 36 weeks of gestation, were included. There was a high level of concordance in the classification of small-for-gestational-age between the two standards (Cohen's kappa = 0.80, p < 0.001). A lower incidence was observed when the INTERGROWTH-21 standard was used (31.6%) compared to the Carrascosa 2008 standard (40.8%), p = 0.03. No significant differences were found in mortality or morbidity among neonates classified as small-for-gestational-age by both standards.

CONCLUSION

The Carrascosa 2008 and INTERGROWTH-21 standards classify small-for-gestational-age infants with comparable morbidity and mortality. We recommend the use of the INTERGROWTH-21 standard for its inclusion of multiple pregnancies, diverse ethnicities, and international comparability.

Lower plasma melatonin levels in non-hypoxic premature newborns associated with neonatal pain

We analyzed plasma melatonin levels in different groups of preterm newborns without hypoxia and their relationship with several perinatal variables like gestational age or neonatal pain. Prospective cohort study of preterm newborns (PTNB) without perinatal hypoxia, Apgar > 6 at 5 min, and oxygen needs on the third day of life. We compared melatonin levels at day 3 of life in different groups of non-hypoxic preterm infants (Student's t-tests, Mann-Whitney U, and chi2) and analyzed the relationship of melatonin with GA, birth weight, neonatal pain (Premature Infant Pain Profile (PIPP) scale), caffeine treatment, parenteral nutrition, or the development of free radical diseases (correlation study, linear regression) and factors associated with moderate/intense pain and free radical diseases (logistic regression analysis). Sixty-one preterm infants with gestational age (GA) of 30.7 ± 2.0 weeks with no oxygen requirements at day 3 of life were studied with plasma melatonin levels of 33.8 ± 12.01 pg/ml. Preterm infants weighing < 1250 g at birth had lower plasma melatonin levels (p = 0.05). Preterm infants with moderate or severe pain (PPIPP > 5) have lower melatonin levels (p = 0.01), and being preterm with PIPP > 5 is associated with lower plasma melatonin levels (p = 0.03). Being very preterm (GA < 32 GS), having low weight for gestational age (LWGA), receiving caffeine treatment, or requiring parenteral nutrition did not modify melatonin levels in non-hypoxic preterm infants (p = NS). Melatonin on day 3 of life in non-hypoxic preterm infants is not associated with later development of free radical diseases (BPD, sepsis, ROP, HIV, NEC).

CONCLUSION

We observed that preterm infants with moderate to severe pain have lower melatonin levels. These findings are relevant because they reinforce the findings of other authors that melatonin supplementation decreases pain and oxidative stress in painful procedures in premature infants. Further studies are needed to evaluate whether melatonin could be used as an analgesic in painful procedures in preterm infants.

TRIAL REGISTRATION

Trial registration was not required since this was an observational study.

WHAT IS KNOWN

• Melatonin is a potent antioxidant and free radical scavenger in newborns under stress conditions: hypoxia, acidosis, hypotension, painful procedures, or parenteral nutrition. • Pain stimulates the production of melatonin. • Various studies conclude that melatonin administration decreases pain during the neonatal period.

WHAT IS NEW

• Non-hypoxic preterm infants with moderate to severe pain (PIPP>5) have lower levels of melatonin. • Administration of caffeine and treatment with parenteral nutrition do not modify melatonin levels in non-hypoxic preterm infants.