Small thymus at birth and neonatal outcome in very-low-birth-weight infants

Abstract

Acute thymic involution in the human fetus and newborn is associated with histological chorioamnionitis, a leading cause of prematurity, neonatal morbidity and mortality [3, 5,12,14]. Positive linear relationships between thymus size, birth weight [7] and gestational age [5] have been reported. Although a small thymus size at birth has been shown to be an accurate predictor for bronchopulmonary dysplasia (BPD) in very-low-birthweight (VLBW) infants [4], no information exists to date on the relationship between thymus size and other adverse neonatal outcomes. A total of 326 consecutive VLBW newborns who were admitted to the neonatal intensive care unit (NICU) in Brindisi and who survived for at least 36 weeks' post-conceptional age were recruited (157 males, 169 females; gestational age: 28.9±3.1 weeks, range: 24-32; birth weight: 1,205±235 g, range: 550-1,490. Over the last 16 years, a minimal handling policy, i.e. nasal continuous positive airway pressure (nCPAP) and/or nasal intermittent positive pressure ventilation (nIPPV) for the treatment of respiratory distress syndrome (RDS), has been used in the Brindisi NICU [9]. Major malformations, primary immunodeficiency disorders and mediastinal diseases were excluded. A single standardised dose of prenatal steroid was used in our population. Thymic size was measured on standard chest radiographs routinely performed for clinical reasons. Thymic size was expressed as the ratio between the transverse diameter of the cardiothymic image at the level of the carina and that of the thorax (CT/T) [2, 4, 5], and a CT/T <0.28 was considered to indicate a small thymic size [2]. Each measurement was made in triplicate and mean values were used for data analysis. Mean intra-and inter-observer coefficients of variation were 3.2% and 5.1%, respectively [1]. Chest radiographs with ill-defined cardiothymic silhouette were excluded. Approval of the Institutional Review Board and informed consent from the parents were obtained. BPD is usually defined as oxygen dependency at 28 days' postnatal age or 36 weeks' post-conceptional age. In this respect, the last definition was not applicable due to the very low incidence of oxygen-dependency at 36 weeks in our population [4,9]. Intraventricular haemorrhage (IVH, grades 1-4] and periventricular leukomalacia (PVLM), necrotising enterocolitis (NEC), retinopathy of prematurity (ROP, grades 1-5), RDS, patent ductus arteriosus (PDA) and seizures were defined according to widely recognised criteria. Sepsis was defined as described [13]. Data were expressed as means ± standard deviation for continuous, normally distributed data and medians with inter-quartile range for non-normal distributions. The t-test or Mann-Whitney U test, and v 2 test or Fisher's exact test were used to compare continuous, normally distributed data, non-parametric continuous data and categorical data, respectively. Data were analysed by multiple logistic regression models, with each of the end-points (RDS, PDA, ROP, PVL, IVH, NEC, sepsis, seizures) as the dependent variab...

Early dynamic changes in pulse oximetry signals in preterm newborns with histologic chorioamnionitis

“…Cumulating evidence indicates that HCA is associated with a fetal inflammatory systemic response syndrome (4,11,46). Our research on acute thymic involution in newborns and fetuses with proven HCA is in line with this notion (22,(47)(48)(49). Although these data are suggestive of a similarity between the systemic inflammatory response syndrome of the fetus/ newborn and that seen in children and adults, to date no information exists on this intriguing issue.…”

In Utero Exposure to Phthalates and Fetal Development

“…Fourthly, HCA is a leading cause of preterm birth [23,[25][26][27][28][29][34][35][36] and we have found an association between phthalate exposure and a shortened duration of pregnancy in humans [6].…”

“…Although suppression of COX-2 expression, mediated by PPARs, has been reported in various tissues and cell lines, some natural PPAR agonists induce cyclooxygenase (COX)-2 expression and activity, the enzyme catalyzing the rate-limiting step leading to the production of prostaglandins associated with labour within intrauterine tissues [14][15][16][17][18][19][20][21]. To this regard, COX-2 is induced during inflammation-mediated preterm labor [22] and it is believed to be overexpressed in chorioamnionitis (CA), a well known fetal systemic inflammatory response syndrome, and a leading cause of fetal/neonatal morbidity and mortality, including fetal death, preterm birth and brain injury [23][24][25][26][27][28][29][30][31][32][33][34][35][36]. On the other hand, EFAs play a critical role for fetal growth and development.…”

Maternal pulse oximetry perfusion index as a predictor of early adverse respiratory neonatal outcome after elective cesarean delivery

“…Prior research has shown the occurrence of an acute fetoneonatal thymic involution following a placental inflammatory process, as a result of a possible activation of the fetal and/or maternal hypothalamic-pituitaryadrenal axis in preterm labor and delivery (32)(33)(34)(35)(36)(37). To this regard, corticotropin releasing factor (CRF) placental receptors may play a major role in activation of the maternal and fetal hypothalamic-pituitary-adrenal axis.…”