Nephrogenesis is ongoing at the time of birth for the majority of preterm infants, but whether postnatal renal development follows a similar trajectory to normal in utero growth is unknown. Here, we ...examined tissue collected at autopsy from 28 kidneys from preterm neonates, whose postnatal survival ranged from 2 to 68 days, including 6 that had restricted intrauterine growth. In addition, we examined kidneys from 32 still-born gestational controls. We assessed the width of the nephrogenic zone, number of glomerular generations, cross-sectional area of the renal corpuscle, and glomerular maturity and morphology. Renal maturation accelerated after preterm birth, with an increased number of glomerular generations and a decreased width of the nephrogenic zone in the kidneys of preterm neonates. Of particular concern, compared with gestational controls, preterm kidneys had a greater percentage of morphologically abnormal glomeruli and a significantly larger cross-sectional area of the renal corpuscle, suggestive of renal hyperfiltration. These observations suggest that the preterm kidney may have fewer functional nephrons, thereby increasing vulnerability to impaired renal function in both the early postnatal period and later in life.
This study aimed to determine the long term effects of resolution of SDB in preschool children, either following treatment or spontaneous recovery, on cognition and behavior. Children diagnosed with ...SDB at 3-5y (N = 35) and non-snoring controls (N = 25), underwent repeat polysomnography (PSG) and cognitive and behavioral assessment 3 years following a baseline study. At follow-up, children with SDB were grouped into Resolved and Unresolved. Resolution was defined as: obstructive apnea hypopnea index (OAHI) ≤1 event/h; no snoring detected on PSG; and no parental report of habitual snoring. 57% (20/35) of children with SDB received treatment, with SDB resolving in 60% (12/20). 43% (15/35) were untreated, of whom 40% (6/15) had spontaneous resolution of SDB. Cognitive reduced between baseline and follow-up, however this was not related to persistent disease, with no difference in cognitive outcomes between Resolved, Unresolved or Control groups. Behavioral functioning remained significantly worse in children originally diagnosed with SDB compared to control children, regardless of resolution. Change in OAHI did not predict cognitive or behavioral outcomes, however a reduction in nocturnal arousals, irrespective of full resolution, was associated with improvement in attention and aggressive behavior. These results suggest that resolution of SDB in preschool children has little effect on cognitive or behavioral outcomes over the long term. The association between sleep fragmentation and behavior appears independent of SDB, however may be moderated by concomitant SDB. This challenges the assumption that treatment of SDB will ameliorate associated cognitive and behavioural deficits and supports the possibility of a SDB phenotype.
Intrauterine growth restriction (IUGR) refers to the situation where a fetus does not grow according to its genetic growth potential. One of the main causes of IUGR is uteroplacental vascular ...insufficiency. Under these circumstances of chronic oxygen and nutrient deprivation, the growth-restricted fetus often displays typical circulatory changes, which in part represent adaptations to the suboptimal intrauterine environment. These fetal adaptations aim to preserve oxygen and nutrient supply to vital organs such as the brain, the heart, and the adrenals. These prenatal circulatory adaptations are thought to lead to an altered development of the cardiovascular system and "program" the fetus for life long cardiovascular morbidities. In this review, we discuss the alterations to cardiovascular structure, function, and control that have been observed in growth-restricted fetuses, neonates, and infants following uteroplacental vascular insufficiency. We also discuss the current knowledge on early life surveillance and interventions to prevent progression into chronic disease.
Good quality sleep of sufficient duration is vital for optimal physiological function and our health. Sleep deprivation is associated with impaired neurocognitive function and emotional control, and ...increases the risk for cardiometabolic diseases, obesity and cancer. Sleep develops during fetal life with the emergence of a recognisable pattern of sleep states in the preterm fetus associated with the development, maturation and connectivity within neural networks in the brain. Despite the physiological importance of sleep, surprisingly little is known about how sleep develops in individuals born preterm. Globally, an estimated 15 million babies are born preterm (<37 weeks gestation) each year, and these babies are at significant risk of neural injury and impaired brain development. This review discusses how sleep develops during fetal and neonatal life, how preterm birth impacts on sleep development to adulthood, and the factors which may contribute to impaired brain and sleep development, leading to altered neurocognitive, behavioural and motor capabilities in the infant and child. Going forward, the challenge is to identify specific risk factors for impaired sleep development in preterm babies to allow for the design of interventions that will improve the quality and quantity of sleep throughout life.
Schematic illustration of how adverse events before and during birth, including the loss of critical placental factors, can impair brain maturation and alter sleep development.
Sudden infant death syndrome Moon, Rachel Y, MD; Horne, Rosemary SC, PhD; Hauck, Fern R, MD
Lancet,
11/2007, Letnik:
370, Številka:
9598
Journal Article, Book Review
Recenzirano
Summary Despite declines in prevalence during the past two decades, sudden infant death syndrome (SIDS) continues to be the leading cause of death for infants aged between 1 month and 1 year in ...developed countries. Behavioural risk factors identified in epidemiological studies include prone and side positions for infant sleep, smoke exposure, soft bedding and sleep surfaces, and overheating. Evidence also suggests that pacifier use at sleep time and room sharing without bed sharing are associated with decreased risk of SIDS. Although the cause of SIDS is unknown, immature cardiorespiratory autonomic control and failure of arousal responsiveness from sleep are important factors. Gene polymorphisms relating to serotonin transport and autonomic nervous system development might make affected infants more vulnerable to SIDS. Campaigns for risk reduction have helped to reduce SIDS incidence by 50–90%. However, to reduce the incidence even further, greater strides must be made in reducing prenatal smoke exposure and implementing other recommended infant care practices. Continued research is needed to identify the pathophysiological basis of SIDS.
Summary Over the past three decades there has been a steady increase in the incidence of preterm birth. The worldwide rate of preterm birth is estimated to be 9.6% of all births, a total of almost 13 ...million births annually. Preterm birth is associated with a range of adverse cardiovascular and central nervous system outcomes, which may be attributed to altered development of these systems following preterm birth. Preterm birth has a considerable impact on cardiovascular parameters with preterm infants displaying higher heart rates and reduced blood pressure when compared to term born infants at matched ages. Furthermore, premature infants have altered autonomic control of cardiovascular parameters which manifests as abnormalities in heart rate variability and baroreflex mediated control of heart rate and blood pressure. As a result, systemic cardiovascular parameters can be unstable following preterm birth which may place stress on the neonatal brain. The brain of a preterm infant is particularly vulnerable to these fluctuations due to immature cerebral haemodynamics. Preterm infants, particularly those who are very preterm or unwell, display fluctuating pressure-passivity between systemic blood pressure and cerebral blood flow representing a considerably increased risk of cerebral haemorrhage or hypoxia. This is further compounded by immaturity of cerebral blood flow–metabolism coupling, which means increased metabolic demand cannot adequately be met by increased cerebral blood flow. It has been suggested that adverse long-term outcomes following preterm birth may occur as a result of exposure to physiological stress either in-utero or early in infancy.
Abstract Objective Sleep disordered breathing (SDB) is common in children and ranges in severity from primary snoring (PS), to obstructive sleep apnea syndrome (OSAS). This study investigated ...everyday function (behavior, attention, executive skills) in children with varying degrees of SDB and control children with no history of SDB recruited from the community. Methods One hundred thirty-six children aged 7–12 were studied. Routine overnight polysomnography (PSG) classified children into 4 groups: PS ( n = 59), mild OSAS ( n = 24), moderate/severe OSAS ( n = 18), and controls ( n = 35). Behavioral function and behavioral aspects of attention and executive function were assessed using the Child Behavior Checklist (CBCL) and the Behavior Rating Inventory of Executive Function (BRIEF). Results Children with all severities of SDB had significantly higher rates of total, internalizing and externalizing behavioral problems compared to control children. Increased rates of behavioral executive dysfunction were also found across the SDB spectrum. Conclusion Our findings suggest that behavioral, attention, and executive function difficulties are present in children with PS as well as OSAS. These results have implications for the treatment of milder forms of SDB, particularly PS, which is commonly viewed as benign.
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