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Keywords: antioxidants; neonatal sex; male disadvantage; breast milk; breastfeeding; macronutrients EN antioxidants neonatal sex male disadvantage breast milk breastfeeding macronutrients N.PAG N.PAG 16 08/29/22 20220801 NES 220801 1. The present study evidences a higher content in several antioxidants in BM of the mothers with male infants, including GSH, one of the most relevant BM antioxidants [[53]]. We did not find sex differences in SOD activity in BM, suggesting that it may not contribute to the observed sex differences in the total antioxidant capacity of BM. Association between Newborn Sex and Lactation Period in Breast Milk Levels Considering the main effects of our models (adjusted by maternal weight, body fat in the first week postpartum, gestational age, and neonatal Z-scores), BM protein content was significant and positively associated with male sex. Total antioxidant capacity analyzed by ABTS method showed a trend towards a positive association with male sex, although it did not reach statistical significance ( I p i -Value = 0.056), while no significant association was found between sex and total antioxidant capacity assessed by FRAP. [Extracted from the article]

Sex differences play a relevant role in cancer susceptibility, incidence and survival. Exploring such differences is difficult because of the close interplay of genetic, epigenetic and hormonal factors. However, a better understanding of the role of such disparities in cancer mechanisms could improve its prevention and therapy. Our study explores how sex differences in pediatric outcomes vary after undergoing first and advanced‐line therapy for hematological malignancies. The primary goal was to evaluate if sex differences in pediatric outcomes after first‐line therapy persist after allogeneic hematopoietic stem cell transplantation (HSCT). The secondary goal was to analyze sex differences in disease risk at onset and pediatric outcomes after first‐line therapy to compare our results with the literature's reported results. Among a total of 485 patients (280 males, 205 females) admitted for hematological malignancies, disease risk at the onset was significantly higher in males (P <.05). One hundred and seventy‐four patients (111 males and 63 females) had a high‐risk disease requiring HSCT. Before HSCT, all patients underwent myeloablative conditioning, which substantially impaired gonadal function. Although the number of boys undergoing HSCT was almost double that of girls, there were no sex‐related differences in overall survival, cancer relapse and complications after HSCT exposure (P >.05). These findings suggest that the existing sex differences in cancer risk ab initio can be somehow flattened by a conditioning regimen, shedding new light on the role of hormonal factors in cancer mechanism and management. [ABSTRACT FROM AUTHOR]

Breast milk (BM) is the best food for newborns. Male sex is associated with a higher risk of fetal programming, prematurity, and adverse postnatal outcome, being that BM is an important health determinant. BM composition is dynamic and modified by several factors, including lactation period, prematurity, maternal nutritional status, and others. This study was designed to evaluate the influence of sex on BM composition during the first month of lactation, focused on macronutrients and antioxidants. Forty-eight breastfeeding women and their fifty-five newborns were recruited at the Hospital Clínico San Carlos (Madrid, Spain). Clinical sociodemographic data and anthropometric parameters were collected. BM samples were obtained at days 7, 14, and 28 of lactation to assess fat (Mojonnier method), protein (Bradford method), and biomarkers of oxidative status: total antioxidant capacity (ABTS and FRAP methods), thiol groups, reduced glutathione, superoxide dismutase and catalase activities, lipid peroxidation, and protein oxidation (spectrophotometric methods). Linear mixed models with random effects adjusted by maternal anthropometry, neonatal Z-scores at birth, and gestational age were used to assess the main effects of sex, lactation period, and their interaction. BM from mothers with male neonates exhibited significantly higher protein, ABTS, FRAP, and GSH levels, while catalase showed the opposite trend. No differences between sexes were observed in SOD, total thiols, and oxidative damage biomarkers. Most changes were observed on day 7 of lactation. Adjusted models demonstrated a significant association between male sex and proteins (β = 2.70 ± 1.20; p-Value = 0.048). In addition, total antioxidant capacity by ABTS (β = 0.11 ± 0.06) and GSH (β = 1.82 ± 0.94) showed a positive trend near significance (p-Value = 0.056; p-Value = 0.064, respectively). In conclusion, transitional milk showed sex differences in composition with higher protein and GSH levels in males. This may represent an advantage in the immediate perinatal period, which may help to counteract the worse adaptation of males to adverse intrauterine environments and prematurity.

A widely accepted concept is that boys are more susceptible than girls to oxidative stress-related complications of prematurity, including bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and periventricular leukomalacia (PVL). We aimed to quantify the effect size of this male disadvantage by performing a systematic review and meta-analysis of cohort studies exploring the association between sex and complications of prematurity. Risk ratios (RRs) and 95% CIs were calculated by a random-effects model. Of 1365 potentially relevant studies, 41 met the inclusion criteria (625,680 infants). Male sex was associated with decreased risk of hypertensive disorders of pregnancy, fetal distress, and C-section, but increased risk of low Apgar score, intubation at birth, respiratory distress, surfactant use, pneumothorax, postnatal steroids, late onset sepsis, any NEC, NEC > stage 1 (RR 1.12, CI 1.06–1.18), any IVH, severe IVH (RR 1.28, CI 1.22–1.34), severe IVH or PVL, any BPD, moderate/severe BPD (RR 1.23, CI 1.18–1.27), severe ROP (RR 1.14, CI 1.07–1.22), and mortality (RR 1.23, CI 1.16–1.30). In conclusion, preterm boys have higher clinical instability and greater need for invasive interventions than preterm girls. This leads to a male disadvantage in mortality and short-term complications of prematurity.

Male preterm infants are at greater risk of respiratory morbidity and mortality than females but mechanisms are poorly understood. Our objective was to identify the basis for the "male disadvantage" following preterm birth using an ovine model of preterm birth in which survival of females is greater than males. At 0.85 of term, fetal sheep underwent surgery (11 female, 10 male) for the implantation of vascular catheters to monitor blood gases and arterial pressure. After cesarean delivery at 0.90 of term, lambs were monitored for 4 h while spontaneously breathing; lambs were then euthanized and static lung compliance measured. We analyzed surfactant phospholipid composition in amniotic fluid and in bronchoalveolar lavage fluid (BALF) taken at necropsy; we also analyzed surfactant protein (SP) expression in lung tissue. Before delivery male fetuses tended to have lower pH (P = 0.052) compared with females. One hour after delivery, males had significantly lower pH and higher arterial partial pressure of CO2 (PaCO2), lactate, glucose, and mean arterial pressure than females. Two males died 1 h after birth. Static lung compliance was 37% lower in males than females (P < 0.05). In BALF, males had significantly more protein, a lower percentage of the phosphatidylcholine (PC) 32:0 (dipalmitoylphosphatidylcholine) and higher percentages of PC34:2 and PC36:2. There were no sex-related differences in lung architecture or expression of SP-A, -B, -C, and -D. The lower lung compliance in male preterm lambs compared with females may be due to altered surfactant phospholipid composition and function. These changes may compromise gas exchange and impair respiratory adaptation after male preterm birth. [ABSTRACT FROM AUTHOR]

Aim: To provide comprehensive data on potential sex differences in maternal and neonatal characteristics, short-term morbidity and neurodevelopmental outcome within an entire geographically determined collective of infants born at a gestational age <32 weeks. Methods: Between 2003 and 2008, we prospectively enrolled all infants born in Tyrol at <32 weeks of gestation; the association between sex, and a wide set of pre- and postnatal factors, post-discharge morbidity and neurodevelopmental outcome was analysed. Results: Girls less frequently suffered from early-onset sepsis than boys (p = 0.030). After adjustment for multiple corrections (Bonferroni's p = 0.003), no sex differences were seen within any maternal or neonatal parameter. Analysis of morbidity revealed a higher readmission rate in boys (p < 0.0001), which was primarily caused by a greater incidence of respiratory problems (p = 0.003). Boys did not show a greater adverse neurodevelopmental outcome at the age of 12 or 24 months. Conclusion: Parents of boys should be prepared for a potentially higher frequency of readmission after initial discharge, but our data currently give no reason for parents of boys to be disproportionately anxious about their neurodevelopmental outcome. Whether boys also enjoy a rosy prognosis for developmental outcome at school age remains to be elucidated. [ABSTRACT FROM AUTHOR]

Different mortality of males and females during early post-hatching development in sexually size-dimorphic bird species is usually attributed to different nutritional requirements of the sexes, because mortality is mostly biassed toward the larger sex. We investigated whether sex-specific embryo mortality in the yellow-legged gull ( Larus michahellis), a size-dimorphic seabird, depends on parental condition. To test this, we experimentally modified parental nutritional conditions by supplementary feeding of yellow-legged gulls during egg formation, to evaluate sex-biassed environmental sensitivity of gull embryos. We found that eggs were larger in supplemented clutches, but egg size did not affect embryo survival. Survival of male gull embryos was more related to parental food conditions than was survival of female embryos. Survival of male embryos in supplemented clutches was greater than in unsupplemented clutches whereas survival of female embryos was similar in both groups. Because size at hatching was similar in both sexes our results suggest that male phenotype disadvantage is not exclusively linked to the energy demands of size-dimorphic development at the embryo stage. [ABSTRACT FROM AUTHOR]

A widely accepted concept is that boys are more susceptible than girls to oxidative stress-related complications of prematurity, including bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and periventricular leukomalacia (PVL). We aimed to quantify the effect size of this male disadvantage by performing a systematic review and meta-analysis of cohort studies exploring the association between sex and complications of prematurity. Risk ratios (RRs) and 95% CIs were calculated by a random-effects model. Of 1365 potentially relevant studies, 41 met the inclusion criteria (625,680 infants). Male sex was associated with decreased risk of hypertensive disorders of pregnancy, fetal distress, and C-section, but increased risk of low Apgar score, intubation at birth, respiratory distress, surfactant use, pneumothorax, postnatal steroids, late onset sepsis, any NEC, NEC > stage 1 (RR 1.12, CI 1.06–1.18), any IVH, severe IVH (RR 1.28, CI 1.22–1.34), severe IVH or PVL, any BPD, moderate/severe BPD (RR 1.23, CI 1.18–1.27), severe ROP (RR 1.14, CI 1.07–1.22), and mortality (RR 1.23, CI 1.16–1.30). In conclusion, preterm boys have higher clinical instability and greater need for invasive interventions than preterm girls. This leads to a male disadvantage in mortality and short-term complications of prematurity. [ABSTRACT FROM AUTHOR]

• Uses mixed methods longitudinal data to examine patterns of dropout among a cohort of rural Honduran youth. • Examines the factors that influence secondary school dropout among these youth. • Through qualitative data, explains how youth describe discontinuation of school, particularly male students who have higher dropout rates. • Identifies important policy implications for countries like Honduras that are attempting to improve rates of secondary school completion. This study uses longitudinal mixed methods data to examine patterns of dropout among a cohort of 1305 Honduran rural youth from the time they were in 6th grade to the age of 20. Based on our analysis of household and student surveys and in-depth interviews, we find that dropout is a major problem, particularly during transition years and during the first year of upper secondary education. Dropout results from the accumulation of push and pull factors that lead students to question whether it is worthwhile to stay enrolled, as they lack opportunities to convert their schooling into valued outcomes. [ABSTRACT FROM AUTHOR]