Ionized magnesium and gestational age.

OBJECTIVE: Investigation of magnesium (Mg) homeostasis has re-emerged as an area of interest in preterm born neonates who are at risk for brain pathology. However, data regarding the association between the biologically active ionized form of Mg and gestational age (GA) at an early stage of life in newborn infants are controversial. METHODS: We evaluated the total and ionized Mg electrolyte (TMg and IMg) as well as the calcium (TCa and ICa) and pH in the cord blood and on day 2 of life in 22 neonates born at different gestational ages (< 32, 32-34 and > or =35 week) without magnesium tocolysis and absence of serious complications during pregnancy and delivery. RESULTS: The IMg fraction that accounted for 68.1+/-5.1% of the TMg in the cord blood and 67.9+/-4.5% of the TMg on day 2 of life, was significantly higher in very preterm infants (GA< 32 week) as compared to neonates with GA > 35 week. Higher IMg levels were correlated with the lower pH that was recorded in the cord blood of the very preterm infants (correlation coefficient, r=-0.80, p< 0.0001) and ICa (r = -0.52, P< 0.01). Lower pH also was correlated with the GA (P< 0.0001). However, standard multiple regression analysis showed significant association between IMg levels and decreased pH but not the gestational age or ICa (beta=-1.10+/-0.21, p< 0.00009). CONCLUSION: Extremely preterm infants even without additional exposure to tocolytic magnesium are at risk for the lower pH associated elevation of ionized Mg, which should be considered during the management of these infants in order to prevent hypermagnesemia-related pathology.

Thrombocytopenia related neonatal outcome in preterms.

OBJECTIVE: To investigate the thrombocytopenia and platelet transfusion related outcome in very preterm infants. METHODS: Cases (n=94) with at least one episode of thrombocytopenia (platelet counts < 150 x 10(9)/L) and controls (n=70) were identified from a database of 1054 neonates with gestational age < or = 32 weeks admitted to a level III NICU. Thrombocytopenia and platelet transfusion related morbidity (IVH, sepsis, NEC, and bleeding) and mortality were analyzed with respect to gestational age (< 28 weeks and 28-32 weeks), severity of thrombocytopenia (mild if platelet count > or = 100 and < 150 x 10(9)/L, moderate if count > or = 50 and < 100 x 10(9)/L, and severe if platelets < 50 x 10(9)/L), age of thrombocytopenia onset (early < 72 hours and late > or =72 hours). RESULTS: The majority of thrombocytopenia (67.0%) was diagnosed after 72 hours of age, and was mild in 12.8%, moderate in 36.2% and severe in 51.0% of the cases. Neonates with severe and moderate thrombocytopenia were more frequently born at lower gestational age and birth weight. NEC and sepsis especially that caused by Candida infection, were associated with severe thrombocytopenic events. The development of IVH was strongly associated with lower gestational age but not the severity and age of thrombocytopenia onset. Mucocutaneous bleeding complicated 18.4% of cases with severe and late-onset thrombocytopenia (7/38). Platelets were transfused to 85.4% of infants with severe and 64.7% of infants with moderate thrombocytopenia (P< 0.02). The gestational age of the majority of the platelet transfused neonates (49/60, 81.7%) was < 28 weeks. Mean gestational age and birth weight, and rates of severe thrombocytopenia, IVH, sepsis and mortality were comparable in transfused vs not-transfused infants with gestational age 28-32 weeks. Platelet transfused neonates with gestational age < 28 weeks had lower birth weights, were more often severely thrombocytopenic, and died more frequently than infants of a similar gestational age who were not transfused. CONCLUSION: Platelet transfusions did not lower mortality in very premature born infants with moderate and severe thrombocytopenia during the NICU admission.

Dysfunction of innate immunity and associated pathology in neonates.

The neutrophils and complement system are the critical elements of innate immunity mainly due to participation in the first line of defense against microorganisms by means of phagocytosis, lysis of bacteria and activation of naive B-lymphocytes. In this report we provide an overview of the up to date information regarding the neutrophil and complement system's functional ability in newborn infants in association with the maternal conditions that exist during the intrauterine stage, gestational age and post-neonatal pathology. The neonates' capacity to control the neutrophil and complement protein activation process has also been discussed because of the evidence that uncontrolled activation of these immune elements provides a significant contribution to the tissue damage and subsequent pathology. The authors are confident that despite the many unanswered questions this review updates their knowledge and points the need for further research to clarify the role of the age-associated dysfunction of neutrophils and complement system in the infection and inflammation related pathology of newborn infants.

Neonatal morbidity and placental pathology.

OBJECTIVE: To investigate the association between gestational age, placental pathology and outcome among preterm births. METHODS: Medical records and placental pathology results of 165 preterm infants (gestational age pound 34 weeks) were used to analyze the development of intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), patent ductus arteriosus (PDA) and sepsis, in association with placental findings in the gestational age categories of 22-27 (n=71) and 28-33 (n=93) weeks. RESULTS: Significant differences were found in placental findings based on gestational age and neonatal morbidity. Lower gestational age was associated with increased infection-related lesions such as chorionic vasculitis (47.9%, P< 0.001) and acute chorioamnionitis (67.6%, P< 0.001). Placental lesions reflecting disturbances of fetal-placental blood flow (infarction, chorionic plate thrombi and basal perivillous fibrin) were predominantly seen in the 28-33 week gestational age category (P< 0.05-0.01). Despite the high prevalence of chorioamnionitis (38.8%), no significant association was found between this lesion and the tested preterm morbidity after controlling for gestational age. Only, villous edema and chorionic vasculitis were identified as independent predictors for the development of IVH (49.2%, ORA 2.57, 95% CI 1.01, 6.58 and 39.3%, ORA1.95, 95% CI 1.01, 4.21, respectively). CONCLUSION: Villous edema and chorionic vasculitis are significant risk factors for the development of the IVH among neonates born at gestational age pound 34 weeks.