Assessment of lung ventilation of premature infants with bronchopulmonary dysplasia at 1.5 Tesla using phase-resolved functional lung magnetic resonance imaging.

BACKGROUND: The most common chronic complication of preterm birth is bronchopulmonary dysplasia (BPD), widely referred to as chronic lung disease of prematurity. All current definitions rely on characterizing the disease based on respiratory support level and do not provide full understanding of the underlying cardiopulmonary pathophysiology. OBJECTIVE: To evaluate a rapid functional lung imaging technique in premature infants and to quantitate pulmonary ventilation using 1.5 Tesla magnetic resonance imaging (MRI). MATERIALS AND METHODS: We conducted a prospective MRI study of 12 premature infants in the neonatal intensive care unit (NICU) using the phase resolved functional lung MRI technique to calculate pulmonary ventilation parameters in preterm infants with and without BPD grade 0/1 (n = 6) and grade 2/3 (n = 6). RESULTS: The total ventilation defect percentage showed a significant difference between groups (16.0% IQR (11.0%,18%) BPD grade 2/3 vs. 8.0% IQR (4.5%,9.0%) BPD grade 0/1, p = 0.01). CONCLUSION: Phase-resolved functional lung MRI is feasible for assessment of ventilation defect percentages in preterm infants and shows regional variation in localized lung function in this population.

Predictors of 24-h outcome in newborns in need of positive pressure ventilation at birth.

BACKGROUND: Birth asphyxia, defined as 5-minute Apgar score <7 in apneic newborns, is a major cause of newborn mortality. Heart rate (HR) response to ventilation is considered an important indicator of effective resuscitation. OBJECTIVES: To describe the relationship between initial HR in apneic newborns, HR responses to ventilation and 24-h survival or death. METHODS: In a Tanzanian hospital, data on all newborns ≥34 weeks gestational age resuscitated between June 2013-January 2017 were recorded using self-inflating bags containing sensors measuring ventilation parameters and expired CO2, dry-electrode electrocardiography sensors, and trained observers. RESULTS: 757 newborns of gestational age 38 ±â€¯2 weeks and birthweight 3131 ±â€¯594 g were included; 706 survived and 51 died. Fetal HR abnormalities (abnormal, undetectable or not assessed) increased the risk of death almost 2-fold (RR = 1.77; CI: 1.07, 2.96, p = 0.027). For every beat/min increase in first detected HR after birth the risk of death was reduced by 2% (RR = 0.98; CI: 0.97, 0.99, p < 0.001). A decrease in HR to <100 beats/minute when ventilation was paused increased the risk of death almost 2-fold (RR = 1.76; CI: 0.96, 3.20, p = 0.066). An initial rapid increase in HR to >100 beats/min in response to treatment reduced the risk of dying by 75% (RR = 0.25; CI: 0.14, 0.44, p < 0.001). A 1% increase in expired CO2 was associated with 28% reduced risk of death (RR = 0.72; CI: 0.62,0.85, p < 0.001). CONCLUSIONS: The risk of death in apneic newborns can be predicted by the fetal HR (absent or abnormal), initial newborn HR (bradycardia), and the HR response to ventilation. These findings stress the importance of reliable fetal HR monitoring during labor and providing effective ventilation following birth to enhance survival.

The relation between given volume and heart rate during newborn resuscitation.

BACKGROUND: During delivery room resuscitation of depressed newborns, provision of appropriate tidal volume (TV) with establishment of functional residual capacity (FRC) is essential for circulatory recovery. Effective positive pressure ventilation (PPV) is associated with a rapid increase in heart rate (HR). The relationship between delivery of TV and HR responses remains unclear. OBJECTIVES: The study objectives were to determine (1) the relationship between a given TV during initial PPV and HR responses of depressed newborns, and (2) the optimal delivered TV associated with a rapid increase in HR. METHODS: In a Tanzanian rural hospital, ventilation and ECG signals were recorded during neonatal resuscitation and stored in Neonatal Resuscitation Monitors. Resuscitators without positive end-expiratory pressure were used for PPV. No oxygen was used. Perinatal events were observed and recorded by research assistants. RESULTS: 215 newborns of gestational age 37.3±1.9 weeks and birth weight 3115±579g were included. There was a non-linear relationship between delivered TV and HR increase. TV of 9.3ml/kg produced the largest increase in HR during PPV. Frequent interruptions of PPV sequences to provide stimulation/suctioning occurred in all cases and were associated with further HR increases, especially for newborns with initial HR<100 beats/minute. CONCLUSIONS: There was a consistent positive relationship between HR increase and delivered TV. The unanticipated finding of a further increase in HR with PPV pauses to provide stimulation/suctioning suggests that most newborns were in primary rather than secondary apnea.

A novel approach to the study of hypoxia-ischemia-induced clinical and subclinical seizures in the neonatal rat.

Perinatal hypoxic-ischemic encephalopathy (HIE) is a major cause of acute mortality and chronic neurologic morbidity in infants and children. HIE is the most common cause of neonatal seizures, and seizure activity in neonates can be clinical, with both EEG and behavioral symptoms, subclinical with only EEG activity, or just behavioral. The accurate detection of these different seizure manifestations and the extent to which they differ in their effects on the neonatal brain continues to be a concern in neonatal medicine. Most experimental studies of the interaction between hypoxia-ischemia (HI) and seizures have utilized a chemical induction of seizures, which may be less clinically relevant. Here, we expanded our model of unilateral cerebral HI in the immature rat to include video EEG and electromyographic recording before, during and after HI in term-equivalent postnatal-day-12 rats. We observed that immature rats display both clinical and subclinical seizures during the period of HI, and that the total number of seizures and time to first seizure correlate with the extent of tissue damage. We also tested the feasibility of developing an automated seizure detection algorithm for the unbiased detection and characterization of the different types of seizure activity observed in this model.

Severe neonatal hypoxic respiratory failure correlates with histological chorioamnionitis and raised concentrations of interleukin 6 (IL6), IL8 and C-reactive protein.

BACKGROUND: The mechanisms contributing to hypoxic respiratory failure (HRF) in term infants are multifactorial. Recent evidence suggests a potential pathogenetic role for inflammation. Nitric oxide (NO), a pulmonary vasodilator, is inhibited by inflammatory mediators that are upregulated in the presence of placental inflammation. OBJECTIVE: To examine the relationship between histological chorioamnionitis and/or funisitis, serum concentrations of inflammatory mediators and severity of HRF. METHODS: Prospective observational study involving term neonates with HRF and normal controls. Blood samples were taken at birth from mixed cord blood, at 6 h and 30 h for cytokines and CRP, and at 72 h and 96 h for CRP. Placentas were examined for chorioamnionitis. The primary outcome was the administration of inhaled nitric oxide (iNO) therapy. Data were analysed using analysis of variance and chi(2) analysis. RESULTS: 32 neonates with hypoxic respiratory failure and 25 controls were enrolled. 14/32 (44%) neonates with HRF required iNO, 9/32 (28%) required high-frequency ventilation and 3/32 (9%) required ECMO; 2/32 (6%) died. Neonates with HRF had more than threefold higher cord levels of interleukin 8 (IL8) than the controls (p<0.05). At 6 h and 30 h, serum IL6, IL8 and CRP were > or =2.2-fold higher in neonates who received iNO (p<0.003). 23/32 (72%) infants with HRF had evidence of histological chorioamnionitis and/or funisitis compared with 5/25 (20%) controls (p<0.001). CONCLUSION: Severe HRF, as defined by the need for iNO, is associated with raised blood levels of proinflammatory mediators and increased occurrence of histological chorioamnionitis and funisitis, suggesting that inflammation contributes to the severity of hypoxic failure.

Glucose-6-phosphate dehydrogenase deficiency in triplets of African-American descent.

Despite the prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency in African Americans, the disorder maybe often overlooked as a diagnosis in the absence of overt signs of hemolysis in neonates with hyperbilirubinemia. We present a case report of anemia and prolonged hyperbilirubinemia due to G6PD deficiency in the absence of hemolysis in dichorionic, triamniotic, preterm triplets of African-American descent.

The genesis of cognitive and behavioral deficits in premature graduates of intensive care.

Increased survival of very low birth weight infants including those born at the cutting edge of viability is associated with substantial cognitive and behavioral deficits at follow-up that has extended into school age and adolescence. These problems have occurred as common in the presence or absence of neurosonographic abnormalities. Factors/events that may predispose to these problems include medical complications of prematurity i.e. chronic lung disease, recurrent episodes of apnea and bradycardia, transient hypothyroxinemia of prematurity, hyperbilirubinemia, nutritional deficiencies, medications used to treat such conditions i.e. glucorticoids, theophylline etc. and stress associated with prolonged hospitalization. With regard to the latter, attachment to multiple devices that limits infant provider interactions, high noise levels and constant light levels are considered to be of particular importance. Experimental evidence is presented that demonstrates the value of positive interactions between the subject and provider with regard to neurobehavioral outcome. Some suggested interventions include reducing noise levels and displacing it with music, modulating light exposure and enhancing infant parent interactions such as kangaroo care. Finally the important postnatal role of social influences on cognitive and behavioral outcomes is discussed.

Neurobehavioral deficits in premature graduates of intensive care--potential medical and neonatal environmental risk factors.

There is growing evidence that a large number of very low birth weight infants are exhibiting neurobehavioral problems in the absence of cerebral palsy at follow-up that has extended into school age and adolescence. Many clinical factors (ie, chronic lung disease, recurrent apnea and bradycardia, transient hypothyroxemia of prematurity, hyperbilirubinemia, nutritional deficiencies, glucocorticoid exposure), as well as stressful environmental conditions, including infant-provider interaction, constant noise, and bright light, may act in combination to impact on the developing brain, even in the absence of overt hemorrhage and/or ischemia. Any potential intervention strategy designed to prevent cognitive and behavioral problems has to account for the numerous biological and clinical conditions and/or interventions, as well as postdischarge social and environmental influences.

Hypermagnesemia does not increase brain intracellular magnesium in newborn swine.

Phosphorus-31 magnetic resonance spectroscopy was used in 2-day (n = 4) and 40-day (n = 4) miniswine to determine whether plasma hypermagnesemia alters brain intracellular magnesium concentration and if the plasma-brain intracellular magnesium relationship changes with age. At control, brain intracellular magnesium concentration was similar in the 2-day (0.24 +/- 0.04 mM) and 40-day groups (0.21 +/- 0.01 mM). Intravenous infusions of magnesium sulfate (MgSO(4), 60 minute) raised plasma magnesium concentration to 4-6 mM in both groups. During and for 3 hours after MgSO(4) infusions, there were no changes in brain intracellular magnesium concentration in either group and no correlation between plasma and brain intracellular magnesium (r = 0.11 and 0.08 for 2- and 40-day groups, respectively). Brain intracellular magnesium concentration appears to be tightly regulated.

Neonatal adrenal hemorrhage: clinical and abdominal sonographic findings.

Four neonates with adrenal hemorrhage are presented. The clinical manifestations included most often an abdominal mass but also anemia, jaundice, hypotension, bluish discoloration of the scrotum, and abdominal calcification. The diagnosis was established in each case upon abdominal sonographic findings. The review of these patients emphasizes the subtle and diverse clinical presentation of adrenal hemorrhage in a neonate and stresses the importance of abdominal sonography in establishing the diagnosis.

Linear hyperechogenicity within the basal ganglia and thalamus of preterm infants.

Linear hyperechogenicity (LHE) within the basal ganglia and thalamus is an uncommon sonographic finding in preterm infants and is of unclear significance. The study objectives were to determine the clinical characteristics and neurodevelopmental outcome in preterm infants who develop LHE. Ten preterm and 20 control infants were evaluated developmentally at 18 months adjusted age using the Bayley Scales of Infant Development. LHE was diagnosed at 4 weeks (range = 1-11). Antenatal glucocorticoid therapy was more common in infants with LHE than in the control infants (90% vs 45%). Four (44%) of nine LHE infants and no control infants were positive for cytomegalovirus (P = 0.02, and three of 10 LHE infants and no control infants had a hypothyroid (P = 0.03). The mental development scores and behavioral evaluation results were lower in the infants with LHE than in the control infants (73.7 +/- 9.7 vs 83.7 +/- 9.4, P = 0.01 and 23.7 +/- 20.1 vs 43.9 +/- 25.4, P = 0.04, respectively). The infants without LHE also had poorer motor quality (22.8 +/- 20. 5 vs 55.7 +/- 37.4, P = 0.02) and lower emotional regulation scores (25.7 +/- 16 vs 42.3 +/- 24, P = 0.06) than the control infants. Preterm infants with LHE are at an increased risk of adverse neurodevelopmental outcome and, in particular, cognitive and behavioral performance. The sonographic evolution of LHE may be a marker of a diffuse insult to the brain.

Outcome following cardiopulmonary resuscitation in the neonate requiring ventilatory assistance.

BACKGROUND: there is limited data regarding the clinical characteristics and outcome of the neonate requiring ventilatory assistance who develops persistent bradycardia (PB) requiring cardiopulmonary resuscitation (CPR). OBJECTIVES: (1) to determine the percentage of newborn infants requiring respiratory assistance who develop PB and require CPR as part of resuscitation; (2) the associated clinical events; and (3) the short term outcome. METHODS: the medical charts of infants admitted to a neonatal intensive care unit who developed PB, defined as a heart rate <80 beats/min requiring CPR, were retrospectively reviewed. RESULTS: for 3 years, 39 (2.6%) of 1485 infants exhibited 62 episodes of PB requiring CPR; this represents 5.6% of 695 intubated infants. Fourteen (36%) infants rapidly responded to chest compressions only with restoration of heart rate within 2 min; termed brief CPR. None died in-hospital. Twenty-five (64%) infants required prolonged chest compressions, i.e. >2 min (termed prolonged CPR); 21 also received epinephrine. The median postnatal age at onset of CPR was 20 days (range 1-148 days) and the duration of CPR was 10 min (range 3-73 min). The more common medical conditions that may have contributed to the PB included severe bronchospasm associated with chronic lung disease (CLD) (n=6), shock associated with sepsis (n=4) and necrotizing enterocolitis (NEC) (n=2), pneumothorax (n=2), inadequate or improper ventilation (n=3), other (n=8). Nineteen (76%) infants died: 13 within 24 h of the event and six from 3 to 194 days following CPR. At 18 months follow-up, four of the six infants evaluated have a moderate to severe neurodevelopmental deficit. Of the nine infants requiring brief CPR who were evaluated, five are developing normally and four have a moderate to severe neurodevelopmental deficit. CONCLUSION: CPR in the neonate who requires ventilatory assistance is not uncommon. When brief in nature, mortality is low and short-term outcome is likely to be determined by the underlying medical condition. When CPR is prolonged, mortality is high and short-term outcome is poor.

Surveillance protocol for the detection of intracranial abnormalities in premature neonates.

OBJECTIVE: To determine the optimal timing of cranial ultrasound scans (USs) for identifying preterm neonates weighing less than 1500 g at birth who develop intracranial complications of prematurity. DESIGN/SETTING: Observational study at an urban county hospital. METHODS: Serial USs from neonates with less than 1500-g birth weight (BW) admitted to the neonatal intensive care unit between January 1995 and December 1996 were reviewed by a pediatric neuroradiologist in a blinded random manner. RESULTS: Two hundred forty-eight neonates (78%) underwent at least 3 USs, 32 (10%) had 2 USs and 37 (12%) only 1 US. The initial US was normal in 156 neonates (49%) and abnormal in 161 (57%). The principal abnormalities included intraventricular hemorrhage (IVH) (n = 74), periventricular echogenicity (PVE) (n = 68), ventriculomegaly (n = 7), and solitary cysts (n = 9). Severe IVH (n = 17) occurred in 13 (11.4%) of 114 neonates at less than 1000-g BW and 4 (5%) of 79 neonates of BW 1000 to 1250 g. In 11 cases (65%), the severe IVH was clinically unsuspected. For neonates weighing less than 1000 g, IVH was diagnosed by days 3 to 5 in 10 (77%) of 13, by days 10 to 14 in 11 (84%) of 13, and by day 28 in all neonates; for neonates 1001 to 1250 g, IVH was diagnosed in 1 (24%) of 4 by days 3 to 5, 2 (50%) of 4 by days 10 to 14, and 3 (75%) of 4 by day 28. One infant's condition was diagnosed on routine US before discharge from the hospital. Cystic periventricular leukomalacia (PVL) was noted in 9 neonates; in 4 of the 9 cases, increased PVE was present on the initial US and cyst formation was obvious by the second US. For 4 neonates (3 with BW <1000 g), all routine USs were negative and cystic PVL was noted on the predischarge US in these cases. Nonobstructive ventriculomegaly in the absence of IVH or cystic PVL was observed in 14 neonates. In 6, it was noted on the initial screening US; in 4 of the cases, it evolved after the third screening US. Two hundred fifty-six neonates had a US before discharge from the hospital; 181 (72%) were normal and 75 (28%) abnormal. Nine significant lesions were identified by the US before discharge from the hospital (ie, severe IVH [n = 1], cystic PVL [n = 4], and ventriculomegaly [n = 4]). CONCLUSIONS: The following screening protocol is recommended: (1) Neonates of less than 1000-g BW: initial US on days 3 to 5 (should identify at least 75% of cases of IVH and some PVE abnormalities); second US on days 10 to 14 (should detect at least 84% of IVH and identify early hydrocephalus and early cyst formation); third scan on day 28 (should detect all cases of IVH, as well as assess PVE and ventricular size); and final scan before discharge from the hospital (should detect approximately 20% of significant late-onset lesions). (2) Neonates of 1000- to 1250-g BW: initial US at days 3 to 5 (should detect at least 40% of significant abnormalities); a second scan at day 28 (should detect at least 70% of significant abnormalities); and a predischarge scan (should detect all late-onset significant lesions). (3) Neonates of 1251- to 1500-g BW: an initial scan at days 3 to 5; and a second scan before discharge from the hospital if the clinical course is complicated. Arch Pediatr Adolesc Med. 2000;154:822-826

Extensive late-onset primary subarachnoid hemorrhage in a preterm infant.

Primary subarachnoid hemorrhage is a rare event in the preterm infant and is most often diagnosed at the postmortem examination. An extremely preterm infant who developed septicemia from Staphylococcus aureus infection in the second postnatal week and presented with hypotension, metabolic acidosis, anemia, thrombocytopenia, and seizures is reported. Cranial ultrasound revealed a large extra-axial fluid collection involving the left parietal cortex that at postmortem examination was observed to be a large left-sided primary subarachnoid hemorrhage. The subarachnoid hemorrhage is most likely secondary to events associated with septic shock and probable disseminated vascular coagulopathy.

Acute changes in arterial carbon dioxide tension and acid-base status and early neurologic characteristics in term infants following perinatal asphyxia.

BACKGROUND: Marked acute changes in arterial carbon dioxide tension (PaCO2) and acid-base status occur in the immediate postnatal period in infants delivered in the presence,of pathologic fetal acidemia (FA) in whom the risk for hypoxic-ischemic cerebral injury is high. The cerebral vasculature is extremely sensitive to changes in PaCO2. However, the relationship between the acute changes in PaCO2 and subsequent neonatal neurologic characteristics remains unclear. OBJECTIVES: (1) To determine the extent of the acute changes in PaCO2 and acid-base status following birth in infants delivered in the presence of pathologic FA and (2) to determine the potential relationship of the initial changes in PaCO2 and neonatal neurologic characteristics. METHODS: PaCO2 and acid base status of cord umbilical arterial blood and initial postnatal arterial blood were studied in 73 term infants admitted to the Neonatal Intensive Care Unit. Infants were categorized in three groups: I, no FA, no respiratory support and normal neonatal neurologic examination (n = 49); II, pathologic FA (umbilical artery pH < or = 7.00, base deficit > or = 12 mEq/l), no respiratory support and normal neonatal neurologic examination (n = 17); III, FA, intubated and with evidence of hypoxic ischemic encephalopathy (HIE) including seizures (n = 7). RESULTS: Demographic characteristics were similar among the three groups, although 5-min Apgar score < or = 5 was more common in group II (47%) and group III (100%) than in group I (4%). Umbilical arterial pH was lower in group III (6.75 +/- 0.18) vs. group II (6.90 +/- 0.09) and in group II vs. group I (6.90 +/- 0.09 vs. 7.19 +/- 0.09) (P < 0.005) and the PaCO2 was higher in group III (141 +/- 37 mmHg) vs. group II (94 +/- 22 mmHg) and in group II vs. group I (94 +/- 22 vs. 60 +/- 13 mmHg) (P < 0.05). The mean base deficit was large but comparable between groups III and II, i.e. 18 +/- 6 vs. 18 +/- 5 mEq/l, respectively, and higher than in group I infants (6 +/- 4 mEq/l) (P < 0.00). At 1 h postnatal age, the mean arterial pH had increased in all groups, i.e. 7.06 +/- 0.15 (group III), 7.25 +/- 0.09 (group II), and 7.31 +/- 0.06 (group I); however, the differences amongst the groups remained significant (P < 0.005). The mean PaCO2 decreased from 94 +/- 22 mmHg (12.5 +/- 2.9 kPa) to 30 +/- 6 mmHg (4.0 +/- 0.8 kPa) for the spontaneously ventilating group II infants and from 141 +/- 37 mmHg (18.8 +/- 4.9 kPa) to 45 +/- 14 mmHg (6.0 +/- 1.9 kPa) in the intubated group III infants (P < 0.005). A repeat PaCO2 at 2 h of age in group III infants had decreased to 29 + 2 mmHg (3.9 +/- 0.3 kPa),which was not different from the PaCO2 at 2 h in group II infants (30 +/- 8 mmHg; 4.0 +/- 1.1 kPa). No significant differences were observed for pH or base deficit at this time. CONCLUSIONS: Marked and rapid changes in PaCO2 and pH were observed in term infants delivered in the presence of pathologic FA. Initial postnatal PaCO2 values varied significantly with the lowest values noted in those infants breathing spontaneously and who exhibited an uneventful neonatal course; higher initial postnatal values, despite mechanical ventilation, were noted in infants with HIE including seizures. Further investigation in this area is imperative in order to better define the optimal respiratory management of the neurologically at-risk infant.

Age-dependent differences in the relationship between plasma and brain extracellular fluid concentrations of magnesium after MgSO4 infusions in miniswine.

Magnesium is a potential neuroprotective agent in the treatment of head injury and ischemia whose efficacy is likely determined by increases in brain extracellular fluid (ECF) magnesium, which in turn depends on its concentration in plasma. The objectives of this study were to: 1) examine the effects of increasing plasma magnesium concentration ([Mg]plasma) to 4-6 mM on brain ECF magnesium concentration ([Mg]ECF) and 2) determine whether maturational changes occur in the transfer of magnesium into brain ECF for newborn and more mature (approximately 1 month old) miniswine. Increases in [Mg]plasma by systemic administration of MgSO4 resulted in similar maximal elevations in brain [Mg]ECF for both age groups (193+/-76% versus 253+/-106% of control for newborn and 1-month-old miniswine, respectively). Calculations of half-lives (t1/2) for the increase and decrease in magnesium concentration (t1/2 uptake and t1/2 clearance) were used to characterize magnesium kinetics in plasma and brain ECF. Plasma magnesium uptake was shorter in 1-month-old (t1/2 = 11.1+/-0.9 min) compared with newborns (12.9+/-1.7 min, p < 0.05). The faster increase in [Mg]plasma probably contributed to a faster uptake of brain [Mg]ECF in 1-month-old compared with newborn swine (t1/2 uptake = 27.9+/-12.8 versus 46.0+/-20.9 min, respectively, p < 0.05). Although plasma magnesium clearance was shorter in 1-month-old swine compared with newborn (t1/2 = 34.3+/-7.0 versus 74.7+/-33.7 min, respectively, p < 0.05), the clearance of magnesium from the brain ECF was similar for each age group. Reductions in blood pressure and heart rate occurred during hypermagnesemia and were similar in each age group. This study shows that acute elevations in [Mg]plasma to 4-6 mM result in similar relative increases in brain [Mg]ECF for both newborn and 1-month-old miniswine. However, there are maturational differences, as demonstrated by the faster rate of magnesium uptake into the ECF observed in the older miniswine.

Maternal fever and neonatal depression: preliminary observations.

The objectives of this study were to determine in term infants: (1) the importance of maternal fever (maternal temperature > 38 degrees C) as a risk factor for neonatal depression and (2) the clinical course of infants admitted to the Neonatal Intensive Care Unit (NICU) born to mothers with fever. For 2 years, 59 (0.24%) of 25,000 term infants had a 5-minute Apgar score < or = 5 and 22 (0.08%) infants were administered chest compressions with or without epinephrine as part of cardiopulmonary resuscitation (CPR) in the delivery room. The perinatal event most commonly associated with a 5-minute Apgar score < or = 5 was maternal fever in 19 infants (32%), with meconium + fetal heart rate (FTHR) abnormalities in 15 (25%), and FTHR abnormalities only in 13 (22%), additional associations (n = 13). By stepwise linear regression analysis, a 5-minute Apgar < or = 5 was related only to the initial infant temperature (p = 0.009, r = 0.33). Maternal fever noted in six infants (27%) was also commonly associated with CPR, as was the presence of meconium + FTHR abnormalities in seven (32%), and FTHR abnormalities only in four (18%). One hundred thirteen (7.5%) of the approximately 1,500 term infants born to mothers with maternal fever were admitted to the NICU. In addition to fever, the labor was complicated by meconium (in 16 infants), meconium + FTHR abnormalities (in 19 infants), and FTHR abnormalities only (in 11 infants). Resuscitative interventions in the delivery room included oxygen only in 43 infants, bag and mask ventilation in 38, continuous positive airway pressure in 10, intubation in 16, and CPR in six infants. Forty-nine infants (43%) had an initial temperature > 38 degrees C including 13 (11%) with an initial temperature > 39 degrees C. Twelve (10%) infants remained intubated on admission and five required ventilator support > 24 hours. One blood culture was positive although all mothers were pretreated with antibiotics. One infant developed hypoxic ischemic encephalopathy including seizures. Maternal fever is the perinatal event most frequently associated with a 5-minute Apgar score < or = 5 and a common association with the need for CPR. Clinicians attending the delivery of a mother with fever should anticipate the potential for neonatal depression; such awareness should facilitate appropriate preparation before delivery and potentially reduce the need for more intensive resuscitation.

Antenatal glucocorticoid, magnesium exposure, and the prevention of brain injury of prematurity.

Prevention of perinatal white matter injury with or without severe intraventricular hemorrhage (IVH) is critical to reduce cerebral palsy (CP) in premature infants. Antenatal therapies that may afford neuroprotection include glucocorticoids, which are associated with a significant reduction in severe IVH, and magnesium, which is associated with reduced CP. Potential protective mechanisms of glucocorticoids include a direct effect on brain, improved respiratory function, and more stable blood pressure hemodynamics. Because magnesium is often administered to mothers with pregnancy-induced hypertension, a condition associated with reduction in severe IVH, the independent neuroprotective role of magnesium remains unclear and warrants additional studies.