First Week Of Life Research Articles

A history of depression and prenatal depression are associated with a lower likelihood of breastfeeding initiation and maintenance, and more breastfeeding problems.

This study tests the hypotheses that lifetime history of depression, and prenatal depression, are associated with a reduced likelihood of breastfeeding initiation (giving the baby any breastmilk during the first week of life) and breastfeeding maintenance (giving the baby breastmilk for at least 6 months), and a greater likelihood of reporting breastfeeding problems. We analyzed data from the Norwegian Mother, Father, and Child cohort study (MoBa), N = 78,307. Mothers reported a lifetime history of depression during the second trimester of pregnancy, and current symptoms of depression during the third trimester using the Hopkins Symptoms Checklist short version (SCL-8). At six months postpartum, mothers self-reported breastfeeding initiation, maintenance, and difficulties. Using binary logistic regression analyses, we report that a lifetime history of depression is associated with a lower likelihood of breastfeeding initiation (OR = 0.751, 95%CI = 0.650-0.938), breastfeeding maintenance (OR = 0.712, 95%CI = 0.669-0.785), and a greater likelihood of breastfeeding difficulties (OR = 1.86, 95%CI = 1.72-2.06). Similarly, prenatal depression was associated with a lower likelihood of breastfeeding initiation (OR = 0.904, 95%CI = 0.878-0.929), breastfeeding maintenance (OR = 0.929, 95%CI = 0.920-0.938), and a greater likelihood of breastfeeding difficulties (OR = 1.10, 95%CI = 1.09-1.12). Results remained largely unchanged when covaried for several confounding variables, including medication use. We provide novel evidence that pre-conception and prenatal symptoms of depression are associated with breastfeeding outcomes. This information could be used to identify women very early in pregnancy who may need additional support with breastfeeding. There is also a need to fully understand the biopsychosocial mechanisms that mediate the relationship between depression prior to birth and breastfeeding outcomes.

Bacteria colonization and gene expression related to immune function in colon mucosa is associated with growth in neonatal calves regardless of live yeast supplementation

BackgroundAs Holstein calves are susceptible to gastrointestinal disorders during the first week of life, understanding how intestinal immune function develops in neonatal calves is important to promote better intestinal health. Feeding probiotics in early life may contribute to host intestinal health by facilitating beneficial bacteria colonization and developing intestinal immune function. The objective of this study was to characterize the impact of early life yeast supplementation and growth on colon mucosa-attached bacteria and host immune function.ResultsTwenty Holstein bull calves received no supplementation (CON) or Saccharomyces cerevisiae boulardii (SCB) from birth to 5 d of life. Colon tissue biopsies were taken within 2 h of life (D0) before the first colostrum feeding and 3 h after the morning feeding at d 5 of age (D5) to analyze mucosa-attached bacteria and colon transcriptome. Metagenome sequencing showed that there was no difference in α and β diversity of mucosa-attached bacteria between day and treatment, but bacteria related to diarrhea were more abundant in the colon mucosa on D0 compared to D5. In addition, qPCR indicated that the absolute abundance of Escherichia coli (E. coli) decreased in the colon mucosa on D5 compared to D0; however, that of Bifidobacterium, Lactobacillus, and Faecalibacterium prausnitzii, which could competitively exclude E. coli, increased in the colon mucosa on D5 compared to D0. RNA-sequencing showed that there were no differentially expressed genes between CON and SCB, but suggested that pathways related to viral infection such as “Interferon Signaling” were activated in the colon mucosa of D5 compared to D0.ConclusionsGrowth affected mucosa-attached bacteria and host immune function in the colon mucosa during the first 5 d of life in dairy calves independently of SCB supplementation. During early life, opportunistic pathogens may decrease due to intestinal environmental changes by beneficial bacteria and/or host immune function. Predicted activation of immune function-related pathways may be the result of host immune function development or suggest other antigens in the intestine during early life. Further studies focusing on the other antigens and host immune function in the colon mucosa are required to better understand intestinal immune function development.

The influence of pre- and postnatal exposure to air pollution and green spaces on infant’s gut microbiota: Results from the MAMI birth cohort study

BackgroundAnimal and human studies indicate that exposure to air pollution and natural environments might modulate the gut microbiota, but epidemiological evidence is very scarce. ObjectivesTo assess the potential impact of pre- and postnatal exposure to air pollution and green spaces on infant gut microbiota assembly and trajectories during the first year of life. MethodsMAMI (“MAternal MIcrobes”) birth cohort (Valencia, Spain, N = 162) was used to study the impact of environmental exposure (acute and chronic) on infant gut microbiota during the first year of life (amplicon-based 16S rRNA sequencing). At 7 days and at 1, 6 and 12 months, residential pre- and postnatal exposure to air pollutants (NO2, black carbon -BC-, PM2.5 and O3) and green spaces indicators (NDVI and area of green spaces at 300, 500 and 1000 m buffers) were obtained. For the association between exposures and alpha diversity indicators linear regression models (cross-sectional analyses) and mixed models, including individual as a random effect (longitudinal analyses), were applied. For the differential taxon analysis, the ANCOM-BC package with a log count transformation and multiple-testing corrections were used. ResultsAcute exposure in the first week of life and chronic postnatal exposure to NO2 were associated with a reduction in microbial alpha diversity, while the effects of green space exposure were not evident. Acute and chronic (prenatal or postnatal) exposure to NO2 resulted in increased abundance of Haemophilus, Akkermansia, Alistipes, Eggerthella, and Tyzerella populations, while increasing green space exposure associated with increased Negativicoccus, Senegalimassilia and Anaerococcus and decreased Tyzzerella and Lachnoclostridium populations. DiscussionWe observed a decrease in the diversity of the gut microbiota and signs of alteration in its composition among infants exposed to higher levels of NO2. Increasing green space exposure was also associated with changes in gut microbial composition. Further research is needed to confirm these findings.

Vaginal Progesterone for Preventing Preterm Birth and Adverse Perinatal Outcomes in Twin Gestations: A Systematic Review and Meta-analysis

(Abstracted from Am J Obstet Gynecol 2023;229:599–616.e3) Preterm birth represents a significant burden to both healthcare systems and individuals. Complications resulting from preterm birth are a leading cause of death in newborns in the first weeks of life and account for 36% of all neonatal deaths, increasing the risk of both short- and long-term complications.

Bowel function in a prospective cohort of 1052 healthy term infants up to 4 months of age

The purpose of this study is to describe the defecation pattern of healthy infants up to 17 weeks of age. We included 1052 healthy term infants from the prospective HELMi cohort (NCT03996304). Parents filled in recurring online questionnaires on feeding, gastrointestinal function, and crying weekly for the first 17 weeks of life. Defecation frequency was highest at the age of 3 weeks (a median of 4 times/day, interquartile range (IQR) 2.9–5). At each time point, the median defecation frequency of breastfed infants was higher than that of infants receiving formula (e.g., at week 17 a median of 2 times/day, IQR 0.9–3.6, and a median of 1.1, IQR 0.6–1.4, respectively). The dominant color of the stool was most often yellow or light brown. Nearly black stools were reported in the first week of life in 3.4%. Nearly half (47.4%) of the infants had green stool color dominating for at least 1 week, with comparable frequency among breastfed (47.7%) and formula-fed (45.2%) infants. Green stools were associated with a higher defecation frequency (linear mixed-effect model p < 0.0001). Occasional blood in stool was reported in 9.3% and recurrent blood in 5.2% of the infants with no difference in stool consistency. Hard stools were rare (≤ 1%). Conclusion: This study enlightens the spectrum of defecation patterns in healthy term infants during the first 17 weeks of life. A better understanding of bowel function helps healthcare professionals distinguish normal from abnormal when addressing defecation, the color of stools, and the type of feeding.What is Known:• Breastfed infants have more frequent and more yellow-colored stools than formula-fed infants.• Stools with green color are often suggested by the parents or even by medical professionals to indicate disease or discomfort in early life.What is New:• Nearly half of the healthy term infants had green stool dominating for at least one week during the first 17 weeks and occasional blood was reported in almost 10% of the infants during this period.• Data on normal variation in bowel function and stool may serve primary health care professionals when educating the families and caretakers of infants.

Incremental supply of fat, lactose, or protein influences the diurnal pattern of heat production and substrate oxidation in preweaning calves

Increasing nutrient supply to dairy calves has well known benefits; however, the effects of milk replacer (MR) composition when supplied in higher amounts are not fully understood, particularly in the first weeks of life. To better understand the metabolism of macronutrient supply in young calves (21 d old), we investigated diurnal patterns of heat production and substrate oxidation in young calves fed MR with an incremental supply of fat, lactose, or protein. Thirty-two groups of 3 mixed-sex Holstein-Friesian newborn calves (3.4 ± 1.6 d of age), were randomly assigned to one of 4 dietary treatments and studied for 21 d. Diets consisted of a basal MR (23.3% CP, 21.2% EE, and 48.8% lactose of DM) fed at 550 kJ/kg BW0.85 per day (CON; n = 24), or the basal MR incrementally supplied with 126 kJ of digestible energy/BW0.85 per day as milk fat (+FAT; n = 23), lactose (+LAC; n = 24), or milk protein (+PRO; n = 23). Calves were fed MR in 2 daily meals and had ad libitum access to water, but were not supplied with any calf starter nor forage. After 2 weeks of adaptation to the diets, groups of 3 calves were placed for 1 wk in an open-circuit respiration chamber for nitrogen and energy balance measurements (lasting 7 d). On d 3, glucose oxidation kinetics was estimated by using [U-13C]glucose. Measurements included total heat production (total energy [HP], activity [Hact] expenditure, resting metabolic rate [RMR]), respiration quotient (RQ), carbohydrate (COX) and fat oxidation (FOX) in 10 min. intervals and averaging these values per hour over days. Incremental supply of lactose and fat increased body fat deposition, with observed patterns in RMR indicating that this increase occurred primarily after the meals. Specifically, the average daily RMR was highest in the +PRO group and lowest in the CON treatment. The HP was higher in the +PRO group and throughout the day, hourly means of HP were higher in this treatment mainly caused by an increase in Hact. The recovery of 13CO2 from oral pulse-dosed [U-13C]glucose was high (77%), and not significantly different between treatments, indicating that ingested lactose was oxidized to a similar extent across treatments. Increasing lactose supply in young calves increased fat retention by reduction in fatty oxidation. Calves fed a MR with additional protein or fat raised RMR persistently throughout the day, whereas the extra lactose supply only affects RMR after the meal. Dietary glucose was almost completely oxidized (77% based on (13C) glucose measurement) regardless of nutrient supplementation. Extra protein supply increased HP and FOX compared with similar intakes of fat and lactose. Fasting heat production (FHP) of young, group-housed calves is comparable to literature values and unaffected by energy intake. Overall, these findings deepen our understanding of how different nutrients affect metabolic processes, fat retention, and energy expenditure in young dairy calves.

Actual electrolyte intake during the first week of life and morbidity in very-low-birthweight infants.

To describe sodium and potassium intake, their sources and plasma concentrations, and the association between intake and morbidity in very-low-birthweight (VLBW, <1500 g) infants during the first week of life. This retrospective cohort study comprised 951 VLBW infants born at <32 weeks. Infants were divided into three groups according to gestational age: 23-26 (n = 275), 27-29 (n = 433) and 30-31 (n = 243) weeks. Data on fluid management and laboratory findings were acquired from an electronic patient information system. The median sodium intake was highest in the 23-26 week group, peaking at 6.4 mmol/kg/day. A significant proportion of sodium derived from intravascular flushes; it reached 27% on day 1 in the 23-26 week group. High cumulative sodium intake in the first postnatal week was associated with weight gain from birth to day 8 in the 23-26 week group. High intake of sodium associated with an increased risk of surgically ligated patent ductus arteriosus (PDA), bronchopulmonary dysplasia and intraventricular haemorrhage, whereas low intake of potassium associated with an increased risk of PDA. Sodium intake in the most premature infants exceeded recommendations during the first postnatal week. Saline flushes accounted for a significant proportion of the sodium load.

Age- and Sex-Dynamic Fluctuations and Reference Intervals for Alkaline Phosphatase Among the Spanish Population.

Interpretation of alkaline phosphatase (ALP) activity is essential for the diagnosis of certain diseases. ALP changes during life and may vary between different populations. To establish reference intervals (RIs) and percentile charts for ALP activity in the Spanish population through a multicentric observational study and to compare the RIs to those defined in other countries. A total of 662 350 ALP measurements from individuals ages 0 to 99 years from 9 Spanish tertiary care centers collected between 2020 and 2022 were analyzed. This study is the largest published in the literature to date. Continuous percentile charts for ALP according to sex and age were established which can be used as RIs. Higher levels are reached during the first weeks of life. In puberty, a differential evolution is observed in both sexes, reaching a peak at 10 to 13 years of age in boys and remaining stable in girls at this age. Significant differences were also observed in adults, higher in men between ages 20 and 49 years and between ages 50 and 79 years in women, as reported in some countries. ALP activity follows an age- and sex-dependent fluctuation with geographic differences. It is important to have appropriate reference values for each population in order to allow for a correct diagnostic interpretation and early diagnosis of diseases related to ALP abnormalities.

Testing the reported long-term advantages of protein-fortified human milk in very low birth weight neonates

Preterm infants are at-risk for extrauterine growth restriction and downward percentile-crossing between birth and discharge. Increased energy and protein intake through fortification of human milk during the first weeks of life has been associated with improved short-term growth and better developmental outcomes. The aim of this study was to evaluate whether these benefits persist up to children school age. The study was designed as an observational study. During hospitalization, 22 very low birth weight preterm infants were fed with increasing protein fortification of human milk (protein supplemented group, PSG). As a control group (CG), 11 preterm infants were fed with standard nutrition regimen. At children school age (9–11 years), we assessed anthropometric data (weight, height, BMI), global health (renal function), and specific psychological outcomes (Child Behavior Checklist 6–18). A global homogeneity between CG and PSG groups emerged: we found no significant differences in weight, height, and BMI, nor in internalizing symptom outcomes (all ps &amp;gt; 0.05). However, mothers reported significantly higher externalizing symptoms for the PSG infants compared to CG infants. Therefore, neonatal enteral protein supplementation in very low birth weight preterm infants leads to no positive nor adverse consequences in long-term assessment, suggesting that benefits are restricted to the neonatal term and first years of age.

Flicker electroretinogram in preterm infants

BackgroundInfants born prematurely are at risk of developing retinopathy of prematurity, which is associated with abnormalities in retinal function as measured using electroretinography. The aim of this study was to record non-invasive flicker electroretinograms (ERGs) in preterm infants and compare function of moderate and very or extremely preterm infants.MethodsIn this non-randomized, cross-sectional study, 40 moderate preterm (gestational age (GA) 34 0/7 to 36 6/7 weeks, Group A) and 40 very or extremely preterm infants (GA ≤ 31 weeks, Group B) were recruited for flicker ERG recording through closed eyelids using the RETeval® device and skin electrodes. Group A was tested within the first week of life and Group B between 34th and 37th week postmenstrual age. Flicker stimuli were presented at 28.3 Hz with stimulus levels of 3, 6, 12, 30 and 50 cd•s/m2. Primary endpoints were peak time (ms) and amplitude (µV).ResultsFlicker ERGs were recordable in most infants with the highest proportion of reproducible ERGs at 30 cd•s/m2. Amplitudes increased with stronger flicker stimulation, while peak times did not differ significantly between stimulus levels nor groups. Amplitudes were significantly greater in Group B at the strongest stimulus level (Mann-Whitney-U-Test=198.00, Z = 4.097, p = <0.001).ConclusionsFeasibility of collecting flicker ERG data in most preterm infants was confirmed. We found no evidence of reduced retinal responses to flicker stimuli associated with extreme prematurity. Higher amplitudes in very and extremely preterm infants could indicate acceleration of retinal development following birth, triggered by visual stimulation.

Cerebral venous thrombosis and deep medullary vein thrombosis: Padua experience over the last two decades.

Cerebral venous thrombosis (CVT) is a cerebrovascular disorder that accounts for 20% of perinatal strokes. CVT incidence ranges from 0.67 to 1.12 per 100,000 newborns, while the incidence of "deep medullary vein thrombosis" (DMVT), a subtype of CVT, cannot be accurately estimated. This study aims to analyze the case history of CVT in the neonatal period, with a specific focus on DMVT. Newborns diagnosed with CVT, with or without DMVT, between January 2002 and April 2023, were collected using the Italian Registry of Infantile Thrombosis (RITI). Cerebral MRIs were reviewed by an expert neuroradiologist following a standardized protocol. Forty-two newborns with CVT were identified, of which 27/42 (64%) had CVT, and the remaining 15/42 (36%) had DMVT (isolated DMVT in 9/15). Symptom onset occurred in the first week of life (median 8days, IQR 4-14) with a male prevalence of 59%. The most common risk factors for CVT were complicated delivery (38%), prematurity (40%), congenital heart diseases (48%), and infections (40%). Seizures were the predominant presenting symptom in 52% of all cases. Hemorrhagic infarction was higher in cases with isolated DMVT (77%) compared to patients with CVT without DMVT (p = 0.013). Antithrombotic treatment was initiated in 36% of patients. Neurological impairment was observed in 48% of cases at discharge, while 18 out of 31 infants (58%) presented one or more neurological deficits at long term follow up. Conclusion:DMVT occurs in over a third of neonates with CVT. Multicentric studies are essential to establish standardized protocols for therapy, neuroimaging, and follow-up in these patients.

Canine Amniotic Fluid at Birth Holds Information about Neonatal Antibody Titres against Core Vaccine Viruses.

There is a growing interest in the composition of amniotic fluid (AF) in both humans and animals. In addition to its nutritional and protective functions for the foetus, current knowledge demonstrates that AF also serves advanced diagnostic, prognostic, and therapeutic roles. Newborn dogs have an underdeveloped immune system, making them highly susceptible to dangerous pathogens such as canine parvovirus (CPV-2), canine infectious hepatitis virus (CAdV-1), and canine distemper virus (CDV), thus exposing them to a high risk of mortality in the first weeks of life. Immunoglobulins G (IgGs) represent the only antibody isotype capable of crossing the placenta in a small amount and have been detected also in canine AF. The primary aim of this study was to investigate the reliability of AF collected at birth as a marker of passive immunity in canine species. For this purpose, total and specific IgGs against CPV-2, CAdV-1, and CDV were investigated and quantified in both maternal plasma and AF collected at the time of caesarean section. The vaccination status of the bitches was also taken into consideration. Since the immune system can be influenced by gestational age, with preterm infants having immature innate and adaptive immunity, IgG concentrations were correlated with amniotic lecithin, sphingomyelin, cortisol, surfactant protein A, and pentraxin 3 levels. In a previous study from our group on foetal maturity these molecules were measured in the same samples. Finally, correlations between their amniotic content and neonatal outcomes were investigated. This study demonstrates that AF analysis at birth can provide valuable insights into neonatal immunity in puppies, offering a non-invasive method to detect potential early health risks, for improved puppy care and management.

The use of two or more courses of low-dose systemic dexamethasone to extubate ventilator-dependent preterm neonates may be associated with a higher prevalence of cerebral palsy at two years of corrected age

BackgroundOur objective was to determine whether the use of two or more courses of low-dose systemic dexamethasone for extubation of ventilator-dependent preterm infants after the first week of life, as proposed in the DART study, is associated with greater neurodevelopmental harm at two years of corrected age, compared to a single course. MethodsRetrospective review at seven level III neonatal intensive care units. Preterm infants who underwent only one course of systemic dexamethasone for extubation were grouped into DART-1; those who underwent two or more courses were grouped into DART-2. Data and outcomes of infants in DART-2 were compared with those in DART-1. Results150 preterm infants were studied: 104 in DART-1 and 46 in DART-2. Patients in DART-2 had a lower gestational age (25 vs. 26 weeks, p = 0.031) and greater morbidity. The average dexamethasone cumulative dose for patients in DART-1 was 0.819 mg/kg, vs. 1.697 mg/kg for patients in DART-2. A total of 14 patients died. The neuromotor and neurosensory assessments at two years of corrected age revealed in the DART-2 survivors, after the multivariate analysis, a higher prevalence of cerebral palsy with functional motor class 2 (OR = 6.837; 95%CI: 1.054–44.337; p = 0.044) and ophthalmological problems requiring the use of glasses (OR = 4.157; 95%CI: 1.026–16.837; p = 0.046). ConclusionsIn this cohort, the use of more than one course of systemic dexamethasone in low doses for extubation of ventilator-dependent premature infants after the first week of life was associated, at two years of corrected age, with a higher prevalence of cerebral palsy with functional motor class 2 and ophthalmological problems requiring the use of glasses.

Nutritional intake and growth until two years of age in moderate and late preterms.

Moderate and late preterm infants (MLPTI) (gestational age 32 0/7-36 6/7 weeks), are at risk for suboptimal growth. This study evaluated adherence to nutritional recommendations until 6 months corrected age (CA), growth until 2 years CA, and associations between nutritional intake and growth until 2 years CA. We prospectively collected nutritional intakes from 100 MLPTI during the first week of life and at 6 weeks, 3 months, and 6 months CA. Anthropometry was assessed at birth, discharge, term age, and at 6 weeks, 3 months, 6 months, 1 year, and 2 years CA. On day 7, <40% reached nutritional recommendations. Thereafter, >80% reached protein recommendations until 6 months of life, but <60% reached energy recommendations. Weight z-scores increased from -0.44 at term-age to 0.59 at 3 months CA, but declined to -0.53 at 2 years CA on the TNO curves. No significant associations were found between nutritional intake and growth until 2 years CA. No associations were demonstrated between nutritional intakes and growth until 2 years CA, despite not reaching recommended intakes. Despite high efforts to optimize growth, MLPTI find their own growth curve in the first 2 years of life. This research is pioneering in identifying how nutrition influences growth in moderate and late preterm infants (MLPTI) up to 2 years corrected age (CA). MLPTI often do not meet the recommended protein and energy intake in their first week of life, suggesting that current guidelines might be too high. No association was demonstrated between nutritional intake and growth of MLPTI in the first 2 years of life. Initially, MLPTI show an increase in weight z-scores from term age up to 3 months CA but experience a decline in weight z-scores at 2 years CA, according to TNO growth charts.

Insulin-like growth factor-1 effects on kidney development in preterm piglets.

Preterm birth disrupts fetal kidney development, potentially leading to postnatal acute kidney injury. Preterm infants are deficient in insulin-like growth factor 1 (IGF-1), a growth factor that stimulates organ development. By utilizing a preterm pig model, this study investigated whether IGF-1 supplementation enhances preterm kidney maturation. Cesarean-delivered preterm pigs were treated systemically IGF-1 or vehicle control for 5, 9 or 19 days after birth. Blood, urine, and kidney tissue were collected for biochemical, histological and gene expression analyses. Age-matched term-born pigs were sacrificed at similar postnatal ages and served as thereference group. Compared with term pigs, preterm pigs exhibited impaired kidney maturation, as indicated by analyses of renal morphology, histopathology, and inflammatory and injury markers. Supplementation with IGF-1 reduced signs of kidney immaturity, particularly in the first week of life, as indicated by improved morphology, upregulated expression of key developmental genes, reduced severity and incidence of microscopic lesions, and decreased levels of inflammatory and injury markers. No association was seen between the symptoms of necrotizing enterocolitis and kidney defects. Preterm birth in pigs impairs kidney maturation and exogenous IGF-1 treatment partially reverses this impairment. Early IGF-1 supplementation could support the development of preterm kidneys. Preterm birth may disrupt kidney development in newborns, potentially leading to morphological changes, injury, and inflammation. Preterm pigs have previously been used as models for preterm infants, but not for kidney development. IGF-1 supplementation promotes kidney maturation and alleviates renal impairments in the first week of life in preterm pigs. IGF-1 may hold potential as a supportive therapy for preterm infants sensitive to acute kidney injury.

Giant Congenital Lobar Emphysema: A Rare Cause of Persistent Respiratory Distress in Neonatal Intensive Care

Congenital lobar emphysema (CLE) is a rare congenital anomaly of the lung causing excessive aeration of one or more lobes of a histologically normal lung. It manifests in the first weeks of life and rarely in the neonatal period, with respiratory distress due to compression atelectasis and often associated with mediastinal displacement. CLE poses a challenge in terms of diagnosis and positive pressure ventilation due to air trapping. We report the case of a newborn presenting with persistent respiratory distress. A thoracic CT scan was performed, confirming the diagnosis of CLE. The definitive diagnosis is provided by histology of the operative specimen, revealing emphysematous lesions. Treatment involves lobectomy after stabilization of respiratory function. Surgical abstention is possible for asymptomatic or paucisymptomatic lesions.

Sex ratio and sex-specific chick mortality in a species with moderate sexual size dimorphism and female brood desertion

An equal sex ratio at the population level is the usual, evolutionarily stable condition. However, at the individual level, it may be adaptive for parents to manipulate the sex of their offspring, especially in species with sexual size dimorphism (SSD) when the costs and benefits of producing sons and daughters can vary. In this study, we investigated the hatching sex ratio (HSR) and fledging sex ratio (FSR) in the Whiskered Tern (Chlidonias hybrida). Despite the fact that SSD exists in Whiskered Terns already at the chick stage, HSR and FSR did not deviate from parity at the population level. We tested the dependence of HSR, FSR and the survival probability of males and females on the individual hatching date, average egg volume (in a clutch) and the number of nestlings. None of these factors influenced HSR. Survival probability was negatively correlated with the number of hatchlings. The proportion of females among the fledglings was positively correlated with the average egg volume per clutch. To better explore the effect of egg volume on the sex ratio, we tested the relationship between exact egg volume and hatchling sex or hatching success at the individual level; but despite the quite large sample size, our analyses failed to reveal any relationship. The sex ratio was equal among chicks that were found dead in a nest, mostly due to starvation, but more female than male chicks disappeared from nests (mostly due to predation), primarily in the first week of life. This indicates that females may be easier to predate, very likely by frogs hunting small chicks.

Antibiotic duration and gastric dysmotility in preterm neonates.

Prolonged antibiotic use after birth is associated with neonatal feeding intolerance and functional gastrointestinal disorders (FGIDs). A gastric dysrhythmia (tachygastria) with frequencies >4-9 cycles per minute, measured by electrogastrography (EGG), is associated with FGIDs. The relationship between prolonged antibiotic use and % time spent in tachygastria is unknown in preterm infants. We aimed to compare weekly changes in % tachygastria between preterm infants receiving long (>48 h) versus short (≤48 h) courses of antibiotics for early onset sepsis evaluation (initiated at <3 days of life). This was a longitudinal, prospective cohort study of 88 preterm infants (<34 weeks' gestation) with weekly EGG recordings from the first week of life until 40 weeks' post-menstrual age, discharge, or death. We calculated % of EGG recording time in tachygastria and determined the mean across weekly sessions. A mixed effects model assessed variance in % tachygastria between the short- and long-antibiotic exposure groups across all weeks. Baseline characteristics were similar between the two groups. There was no difference in % tachygastria between short and long antibiotic exposure groups across nine postnatal weeks (p = 0.08). Early, prolonged antibiotic exposure among preterm infants may not lead to significant gastric dysrhythmia. Future studies including larger sample sizes and a "no antibiotic" exposure arm are essential in elucidating this potential relationship.

PSIV-14 Assessing sow and suckling pig hemoglobin status in a single lactation following one or two iron supplementations of piglets in a commercial farm

Abstract Newborn piglets are typically anemic at birth [defined as blood hemoglobin concentration (Hb) &amp;lt; 10 g/dL] and sow’s milk contains negligible amounts of iron; common commercial practice is one dose of injectable iron in the first week of life. However, a considerable proportion of piglets have decreased Hb at weaning which may have implications on post-wean performance. Thus, there is interest in additional iron supplementation before weaning. The primary objective of this study was to evaluate the impact of one or two iron supplementations on offspring performance. A total of 172 sows (parity 1 to 8) and litters (n = 2,378 piglets) were assigned in a randomized complete block design to Control [piglets received one injectable iron dose (400 mg)], SUPoral (injectable iron as Control plus oral iron supplement at 1oz/litter per day for 8 d before weaning), or SUPinject (injectable iron as Control plus 100 mg 7 d before weaning). According to barn stand protocol, the first iron dose was provided to all piglets on d 7 after the initiation of farrowing. Sow Hb status was determined at entry to farrowing house and weaning; -Hb status of all born alive piglets was measured within 28 of birth and at weaning. Analysis of variance compared the effect of iron supplementation, parity, and their interaction on piglet Hb status. Sow Hb at entry (9.3, 10.4, and 9.6 g/dL ± 0.15, respectively) was less (P &amp;lt; 0.001) for parity 4-8 sows than parity 1, with parity 2-3 intermediate and no difference between parity groups at weaning (9.5 g/dL ± 0.16). Litter size at birth (total or born alive) and preweaning mortality did not differ between treatments. Piglet Hb at birth was not different between treatments; however, 85% of piglets from parity 4-8 sows were deemed anemic at birth compared with 72 and 76% in parity 1 and 2-3 sows, respectively (P &amp;lt; 0.05). Immediately before additional iron supplementation, Control piglets had lower (P &amp;lt; 0.0001) Hb than SUPoral and SUPinject piglets (7.4 vs 8.0 and 8.1 g/dL ± 0.12, respectively). At weaning, there were no differences in piglet Hb by iron supplementation treatments (11.4 g/dL ± 0.07). However, the percentage of piglets within a litter deemed anemic at weaning was greater (30%; P &amp;lt; 0.011) in parity 4-8 sows compared with parity 1 sows at 13%. There was no difference in piglet body weight at weaning between treatment groups or by parity grouping. In this study, additional iron supplementation before weaning had minimal impact on piglet iron status or growth. The decreased Hb at entry in older sows combined with greater proportion of anemic piglets at birth or weaning suggests greater attention to sow iron intake may be warranted.

Comparative efficacy of volume expansion, inotropes and vasopressors in preterm neonates with probable transitional circulatory instability in the first week of life: a systematic review and network meta-analysis

BackgroundThere exists limited agreement on the recommendations for the treatment of transitional circulatory instability (TCI) in preterm neonatesObjectiveTo compare the efficacy of various interventions used to treat TCIMethodsMedline and Embase...