The adverse neuro-developmental effects of postnatal steroids in the preterm infant: a systematic review of RCTs

Prospective evaluation of postnatal steroid administration: a 1-year experience from the California Perinatal Quality Care Collaborative

OBJECTIVE

Postnatal steroids (PNSs) are used frequently to prevent or treat chronic lung disease (CLD) in the very low birth weight (VLBW) infant, and their use continues despite concerns regarding an increased incidence of longer-term neurodevelopmental abnormalities in such infants. More recently, there has been a suggestion that corticosteroids may be a useful alternative therapy for hypotension in VLBW infants, but there have been no prospective reports of such use for a current cohort of VLBW infants.

METHODS

The California Perinatal Quality Care Collaborative (CPQCC) requested members to supplement their routine Vermont Oxford Network data collection with additional information on any VLBW infant treated during their hospital course with PNS, for any indication. The indication, actual agent used, total initial daily dose, age at treatment, type of respiratory support, mean airway pressure, fraction of inspired oxygen, and duration of first dosing were recorded.

RESULTS

From April 2002 to March 2003 in California, 22 of the 62 CPQCC hospitals reported supplemental data, if applicable, from a cohort of 1401 VLBW infants (expanded data group [EDG]), representing 33.2% of the VLBW infants registered with the CPQCC during the 12-month period. PNSs for CLD were administered to 8.2% of all VLBW infants in 2003, 8.6% of infants in the 42 hospitals that did not submit supplemental data (routine data-set group, compared with 7.6% in EDG hospitals). Of the 1401 VLBW infants in the EDG, 19.3% received PNSs; 3.6% received PNSs for only CLD, 11.8% for only non-CLD indications, and 4.0% for both indications. At all birth weight categories, non-CLD use was significantly greater than CLD use. The most common non-CLD indication was hypotension, followed by extubation stridor, for which 36 (16.3%) infants were treated. For hypotension, medications used were hydrocortisone followed by dexamethasone. Infants treated with PNSs exclusively for hypotension had a significantly higher incidence of intraventricular hemorrhage, periventricular leukomalacia, and death when compared with infants treated only for CLD or those who did not receive PNSs.

CONCLUSIONS

The common early use of hydrocortisone for hypotension and the high morbidity and mortality in children receiving such treatment has not been recognized previously and prospective trials evaluating the short- and long-term risk/benefit of such treatment are urgently required.

Lasting effects of developmental dexamethasone treatment on neural cell number and size, synaptic activity, and cell signaling: critical periods of vulnerability, dose-effect relationships, regional targets, and sex selectivity

Glucocorticoids administered to prevent respiratory distress in preterm infants are associated with neurodevelopmental disorders. To evaluate the long-term effects on forebrain development, we treated developing rats with dexamethasone (Dex) at 0.05, 0.2, or 0.8 mg/kg, doses below or spanning the range in clinical use, testing the effects of administration during three different stages: gestational days 17-19, postnatal days 1-3, or postnatal days 7-9. In adulthood, we assessed biomarkers of neural cell number and size, cholinergic presynaptic activity, neurotransmitter receptor expression, and synaptic signaling mediated through adenylyl cyclase (AC), in the cerebral cortex, hippocampus, and striatum. Even at doses that were devoid of lasting effects on somatic growth, Dex elicited deficits in the number and size of neural cells, with the largest effect in the cerebral cortex. Indices of cholinergic synaptic function (choline acetyltransferase, hemicholinium-3 binding) indicated substantial hyperactivity in males, especially in the hippocampus, effectively eliminating the normal sex differences for these parameters. However, the largest effects were seen for cerebrocortical cell signaling mediated by AC, where Dex treatment markedly elevated overall activity while obtunding the function of G-protein-coupled catecholaminergic or cholinergic receptors that stimulate or inhibit AC; uncoupling was noted despite receptor upregulation. Again, the effects on signaling were larger in males and offset the normal sex differences in AC. These results indicate that, during critical developmental periods, Dex administration evokes lasting alterations in neural cell numbers and synaptic function in forebrain regions, even at doses below those used in preterm infants.

Large-Dose Pretreatment with Methylprednisolone Fails to Attenuate Neuronal Injury After Deep Hypothermic Circulatory Arrest in a Neonatal Piglet Model

Conflicting results have been reported with regard to the neuroprotective effects of steroid treatment with cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA). We evaluated the mode and severity of neuronal cell injury in neonatal piglets after prolonged DHCA and the possible neuroprotective effect of systemic pretreatment (>6 h before surgery) with large-dose methylprednisolone (MP). Nineteen neonatal piglets (age, <10 days; weight, 2.1 +/- 0.5 kg) were randomly assigned to 2 groups: 7 animals were pretreated with large-dose systemic MP (30 mg/kg) 24 h before surgery, and 12 animals without pharmacological pretreatment (saline) served as control groups. All animals were connected to full-flow CPB with cooling to 15 degrees C and 120 min of DHCA. After rewarming to 38.5 degrees C with CPB, animals were weaned from CPB and survived 6 h before they were killed, and the brain was prepared for light and electron microscopy, immunohistochemistry, and TUNEL-staining. Quantitative histological studies were performed in hippocampus, cortex, cerebellum, and caudate nucleus. Systemic pretreatment with large-dose MP lead to persistent hyperglycemia but no significant changes of cerebral perfusion. Necrotic and apoptotic neuronal cell death were detected in all analyzed brain regions after 120 min of DHCA. In comparison to the control group, large-dose pretreatment with systemic MP lead to an increase of necrotic neuronal cell death and induced significant neuronal apoptosis in the dentate gyrus of the hippocampus (P = 0.001). In conclusion, systemic pretreatment with large-dose MP fails to attenuate neuronal cell injury after prolonged DHCA and induces regional neuronal apoptosis in the dentate gyrus.

Prenatal stress, the hypothalamic-pituitary-adrenal axis, and fetal and infant neurobehaviour

BACKGROUND

Although it has long been acknowledged that chronic HPA axis dysregulation impacts on adult neural function, little attention has been paid to the impact that disturbances of the maternal HPA axis may have on the developing fetal brain.

AIM

This editorial examines the associations between prenatal stress, neuroendocrine functioning, and behavioural outcome in both animal and human offspring, with a particular focus on the relationship between prenatal stress and human fetal and infant neurobehaviour.

STUDY DESIGN

Using electronic databases, a computerized search of published and unpublished data was undertaken.

RESULTS

There is growing evidence that prenatal stress impacts on offspring neural function and behaviour in animal populations. That these findings may be applicable to human fetal neurobehaviour and infant development and outcome is gaining research attention, and the potential importance of the timing of pregnancy stress is being increasingly highlighted.

CONCLUSIONS

There is a pressing need for more research into the role of maternal stress and anxiety during pregnancy on human fetal and infant outcomes. Future studies should prospectively pair physiological and psychological measures both pre- and postnatally if the HPA axis function of the mother and her infant is to be more fully understood.

Disruption of rat forebrain development by glucocorticoids: critical perinatal periods for effects on neural cell acquisition and on cell signaling cascades mediating noradrenergic and cholinergic neurotransmitter/neurotrophic responses

Glucocorticoids are the consensus treatment for the prevention of respiratory distress in preterm infants, but there is evidence for increased incidence of neurodevelopmental disorders as a result of their administration. We administered dexamethasone (Dex) to developing rats at doses below or within the range of those used clinically, evaluating the effects on forebrain development with exposure in three different stages: gestational days 17-19, postnatal days 1-3, or postnatal days 7-9. At 24 h after the last dose, we evaluated biomarkers of neural cell acquisition and growth, synaptic development, neurotransmitter receptor expression, and synaptic signaling mediated by adenylyl cyclase (AC). Dex impaired the acquisition of neural cells, with a peak effect when given in the immediate postnatal period. In association with this defect, Dex also elicited biphasic effects on cholinergic presynaptic development, promoting synaptic maturation at a dose (0.05 mg/kg) well below those used therapeutically, whereas the effect was diminished or lost when doses were increased to 0.2 or 0.8 mg/kg. Dex given postnatally also disrupted the expression of adrenergic receptors known to participate in neurotrophic modeling of the developing brain and evoked massive induction of AC activity. As a consequence, disparate receptor inputs all produced cyclic AMP overproduction, a likely contributor to disrupted patterns of cell replication, differentiation, and apoptosis. Superimposed on the heterologous AC induction, Dex impaired specific receptor-mediated cholinergic and adrenergic signals. These results indicate that, during a critical developmental period, Dex administration leads to widespread interference with forebrain development, likely contributing to eventual, adverse neurobehavioral outcomes.

Gestational dexamethasone treatment elicits sex-dependent alterations in locomotor activity, reward-based memory and hippocampal cholinergic function in adolescent and adult rats

Glucocorticoids are the consensus treatment for preventing respiratory distress syndrome in preterm infants but there is emerging evidence of subsequent neurobehavioral abnormalities, independent of somatic growth effects. Pregnant rats were given 0.2 mg/kg of dexamethasone, a dose commensurate with clinical use, on gestational days 17-19 and behavioral evaluations were made on the offspring in adolescence and adulthood. The dexamethasone groups had the same body weights as the controls but nevertheless displayed long-term, sex-selective alterations in locomotor and cognitive behaviors. In the figure-8 activity apparatus, dexamethasone treatment ablated the normal sex differences in locomotor activity by reducing values in females to the lower level typical of males; habituation of activity similarly was impaired in females, reducing the profile to match that of control males, while male rats in the dexamethasone group showed a partially feminized pattern of habituation. In the 8-arm radial maze, control rats displayed typical sex differences, with male rats performing more accurately than females. Dexamethasone treatment eliminated this normal dichotomy, delaying learning in males while improving performance in females to the level normally seen in control males. Finally, we assessed hippocampal [3H]hemicholinium-3 binding as a biomarker for cholinergic synaptic activity, and again found loss of sex differences in the dexamethasone group: values in males were increased to the higher levels typical of females. These results indicate that gestational treatment with dexamethasone obtunds the normal sex differences in neurochemistry and behavior that are typically seen in adolescence in adulthood, thus producing sex-selective alterations in activity, learning, and memory.

Neonatal glucocorticosteroid treatment causes systolic dysfunction and compensatory dilation in early life: studies in 4-week-old prepubertal rats

Glucocorticosteroid treatment is widely used to prevent chronic lung disease in premature infants. Recent studies in adult rats, treated with dexamethasone in the neonatal period, report negative long-term effects on the heart and severely reduced life expectancy. We treated neonatal rats with dexamethasone and studied cardiac function after 4 wk (prepubertal age) to investigate whether the late effects as previously described are preceded by detectable alterations in cardiac function at a younger age. Male rat pups (n = 12) were injected intraperitoneally with dexamethasone on d 1, 2, and 3 (0.5, 0.3, and 0.1 mug/g) of life. Control pups (n = 10) received saline. At 4 wk the animals were anesthetized, and a pressure-conductance catheter was introduced into the left ventricle to measure pressure-volume loops. Cardiac function was measured and pressure-volume relations were determined to quantify intrinsic systolic and diastolic function. Subsequently, hearts were excised for histologic examination. Compared with saline-treated animals, dexamethasone-treated rats had a reduced ventricular weight (270 +/- 40 versus 371 +/- 23 mg, p < 0.001) and reduced systolic function (end-systolic elastance: 1.24 +/- 0.43 versus 2.50 +/- 1.39 mm Hg/muL, p = 0.028). Cardiac output was maintained and end-diastolic volume was increased (84 +/- 23 versus 59 +/- 19 microL, p = 0.012) indicating a state of compensatory dilatation. Heart rate, diastolic function, and systemic vascular resistance were unchanged. Neonatal dexamethasone treatment causes cardiac alterations that can be detected in the prepubertal period and that may precede severe cardiac dysfunction later in life. If our findings are confirmed in humans, this may have consequences for a large patient population and cardiac screening at young age may be indicated to enable secondary prevention.

The safety, pharmacokinetics, and anti-inflammatory effects of intratracheal recombinant human Clara cell protein in premature infants with respiratory distress syndrome

Clara cell 10-kD protein (CC10) is a potent anti-inflammatory protein that is normally abundant in the respiratory tract. CC10 is deficient and oxidized in premature infants with poor clinical outcome (death or the development of bronchopulmonary dysplasia). The safety, pharmacokinetics, and anti-inflammatory activity of recombinant human CC10 (rhCC10) were evaluated in a randomized, placebo-controlled, double-blinded, multicenter trial in premature infants with respiratory distress syndrome. A total of 22 infants (mean birth weight: 932 g; gestational age: 26.9 wk) received one intratracheal dose of placebo (n = 7) or 1.5 mg/kg (n = 8) or 5 mg/kg (n = 7) rhCC10 within 4 h of surfactant treatment. Pharmacokinetic analyses demonstrated that the serum half-life was 11.6 (1.5 mg/kg group) and 9.9 h (5 mg/kg group). Excess circulating CC10 was eliminated via the urine within 48 h. rhCC10-treated infants showed significant reductions in total cell count (p < 0.0002), neutrophil counts (p < 0.001), and total protein concentrations (p < 0.01) and tended to have decreased IL-6 (p < 0.07) in tracheal aspirate fluid collected over the first 3 d of life. Infants in all three groups showed comparable growth. At 36 wk postmenstrual age, five of seven infants were still hospitalized and two of seven infants were receiving oxygen in the placebo group compared with two of seven hospitalized and one of seven receiving oxygen in the 1.5-mg/kg group and four of six hospitalized and three of six receiving oxygen in the 5-mg/kg group. A single intratracheal dose of rhCC10 was well tolerated and had significant anti-inflammatory effects in the lung. Multiple doses of rhCC10 will be investigated for efficacy in reducing pulmonary inflammation and ameliorating bronchopulmonary dysplasia in future studies.

Structural and functional brain development after hydrocortisone treatment for neonatal chronic lung disease

OBJECTIVE

There is much concern about potential neurodevelopmental impairment after neonatal corticosteroid treatment for chronic lung disease. Dexamethasone is the corticosteroid most often used in this clinical setting, and it has been shown to impair cortical growth among preterm infants. This study evaluated long-term effects of prematurity itself and of neonatal hydrocortisone treatment on structural and functional brain development using three-dimensional MRI with advanced image-processing and neurocognitive assessments.

METHODS

Sixty children born preterm, including 25 children treated with hydrocortisone and 35 children not treated with hydrocortisone, and 21 children born at term were evaluated, at a mean age of 8 years, with quantitative MRI and neurocognitive assessments (Wechsler Intelligence Scales for Children-Revised [WISC-R]). Automatic image segmentation was used to determine the tissue volumes of cerebral gray matter, white matter, and cerebrospinal fluid. In addition, the volume of the hippocampus was determined manually. WISC-R scores were recorded as mean intelligence scores at evaluation. Neonatal hydrocortisone treatment for chronic lung disease consisted of a starting dose of 5 mg/kg per day tapered over a minimum of 3 weeks.

RESULTS

Cerebral gray matter volume was reduced among preterm children (regardless of hydrocortisone treatment), compared with children born at term (preterm: 649 +/- 4.4 mL; term: 666 +/- 7.3 mL). Birth weight was shown to correlate with gray matter volume at 8 years of age in the preterm group (r = 0.421). Cerebrospinal fluid volume was increased among children born preterm, compared with children born at term (preterm: 228 +/- 4.9 mL; term: 206 +/- 8.2 mL). Total hippocampal volume tended to be lower among children born preterm, with a more pronounced reduction of hippocampal volume among boys (preterm: 6.1 +/- 0.13 mL; term: 6.56 +/- 0.2 mL). The WISC-R score was lower for children born preterm, compared with children born at term (preterm: 99.4 +/- 12.4; term: 109.6 +/- 8.8). Children treated with neonatal hydrocortisone had very similar volumes of gray matter (preterm with hydrocortisone: 650 +/- 7.0 mL; preterm without hydrocortisone: 640 +/- 5.6 mL), white matter (preterm with hydrocortisone: 503 +/- 6.1 mL; preterm without hydrocortisone: 510 +/- 4.9 mL), and cerebrospinal fluid (preterm with hydrocortisone: 227 +/- 7.4 mL; preterm without hydrocortisone: 224 +/- 6.0 mL), compared with untreated infants. The hippocampal volumes were similar in the 2 groups (preterm with hydrocortisone: 5.92 +/- 0.15 mL; preterm without hydrocortisone: 5.81 +/- 0.12 mL). The WISC-R score assessments were within the normal range for both groups, with no difference between the groups (preterm with hydrocortisone: 100.8 +/- 13; preterm without hydrocortisone: 98.6 +/- 12.3).

CONCLUSIONS

Prematurity is associated with mild brain structural differences that persist at 8 years of age, with associated lower scores in neurocognitive assessments. The data suggest that perinatal hydrocortisone given at the described dosage has no long-term effects on either neurostructural brain development or neurocognitive outcomes.

Diagnosis and treatment of neonatal hypotension outside the transitional period

The etiology and pathophysiology of the circulatory compromise are among the primary determinants of the clinical presentation of patients with neonatal shock. Therefore, in the absence of direct assessment of cardiac output and organ blood flow, the characteristic clinical presentation itself may guide the initial management of the circulatory compromise. This chapter discusses different pathophysiology-driven management approaches to a number of characteristic clinical presentations of neonatal shock. The clinical presentations discussed in detail are the hypotensive very low birth weight neonate with a hemodynamically significant patent ductus arteriosus, and the preterm or term neonate with perinatal depression, pressor/inotrope resistance and relative adrenal insufficiency, and with specific systemic inflammatory response syndrome. In the absence of information from appropriately designed, randomized clinical trials, management of neonatal shock remains based on pathophysiology and experience. Thus, as there is little evidence for the effectiveness of these management approaches to improve mortality and short-and long-term outcome, the therapeutic approaches described in this chapter should be carefully evaluated and cautiously entertained when treating a neonate with circulatory compromise.

Fetal arrhythmias: the Saint-Justine hospital experience

We intend to review our experience with the investigation and management of foetal arrhythmia on the basis of superior vena cava/ascending aorta (SVC/AA) Doppler flow velocity recordings. Irregular rhythms n = 307. Premature atrial and ventricular contractions were easily identified and generally self-limited in time. Sustained bradycardia n = 19. Four had sinus bradycardia, six presented with blocked atrial bigeminism, three showed 2:1, and five had a complete atrio-ventricular (AV) block. Another foetus that presented with first-degree AV block developed a Luciani-Wenckebach phenomenon 1 week later. These different types of bradycardia were all identified on SVC/AA Doppler recordings. Tachyarrhythmia n = 30. Five types of tachyarrhythmia were observed: Type I: Short ventriculo-atrial (VA) tachycardia (VA < AV), n = 11. Ten foetuses of this group presented a distinctive Doppler flow velocity pattern characterised by 1:1 AV conduction and a tall atrial wave ('a' wave) superimposed on the aortic ejection wave. They were considered to have re-entrant tachycardia through a fast-conducting AV accessory pathway; all 10 responded to digoxin therapy. The eleventh foetus with short VA tachycardia had atrial ectopic tachycardia with AV node dysfunction; he was treated successfully with sotalol. Type II: Long VA tachycardia (VA > AV): n = 8. In seven cases, an 'a' wave of normal amplitude with normal AV time interval could be clearly identified in front of the aortic ejection wave: one foetus in this group was considered to be in sinus tachycardia based on the variability of its heart rate; in another, sudden onset of tachycardia triggered by extrasystoles led to the possibility of permanent junctional reciprocating tachycardia (PJRT). The five other foetuses had atrial ectopic tachycardia. The last foetus presented with AV and VA intervals of the same duration and a heart rate of 210 beats/min; he did not respond either to digoxin or to sotalol, and was found after birth to have PJRT. The drug of first choice in this group was sotalol. Type III: Simultaneous onset of atrial and ventricular contractions: n = 3. These foetuses were classified as junctional ectopic tachycardia. Two responded to amiodarone. The other foetus converted spontaneously to sinus rhythm. Type IV: Flutter: n = 7. All presented with 2:1 AV relationship except one who had a variable block. Digoxin was prescribed as a first choice associated with sotalol in three cases. Conversion to sinus rhythm was documented in all; however, one hydropic foetus with advanced cardiomyopathy died one day after birth. Type V: Ventricular tachycardia: n = 1. This 30-week foetus presented alternance of AV dissociation (atrial rate: 130, ventricular rate: 170 beats/min) and atrial capture (ventricular rate of 138 beats/min). The arrhythmia responded well to propanol, and no recurrence was recorded after birth. Precise prenatal identification of arrhythmia type can be achieved with the SVC/AA Doppler approach. Such information allows for a better management and a rational choice of appropriate anti-arrhythmic drug.

Improved survival rates with increased neurodevelopmental disability for extremely low birth weight infants in the 1990s

BACKGROUND

Advances in perinatal care have resulted in increased survival rates for extremely low birth weight children. We sought to examine the relative changes in rates of survival and neurodevelopmental impairment at 20 months of corrected age among 500- to 999-g birth weight infants born at our perinatal center during 2 periods, before and after the introduction of surfactant therapy in 1990.

METHODS

Four hundred ninety-six infants with birth weights of 500 to 999 g were born at our perinatal center during period I (1982-1989) (mean body weight: 762 g; mean gestational age: 25.8 weeks) and 682 during period II (1990-1998) (mean body weight: 756 g; mean gestational age: 25.5 weeks). Rates of death and survival with and without neurodevelopmental impairment at 20 months of corrected age for the 2 periods were compared with logistic regression analyses, with adjustment for gestational age.

RESULTS

Survival rates increased from 49% during period I to 67% during period II. Neonatal morbidity rates also increased during period II, including rates of sepsis (from 37% to 51%), periventricular leukomalacia (from 2% to 7%), and chronic lung disease, defined as oxygen dependence at 36 weeks of corrected age (from 32% to 43%). Rates of severe cranial ultrasound abnormalities were similar (22% vs 22%). Among children monitored, the rate of neurologic abnormalities, including cerebral palsy, increased from 16% during period I to 25% during period II and the rate of deafness increased from 3% to 7%. The overall rate of neurodevelopmental impairment (major neurosensory abnormality and/or Bayley Mental Developmental Index score of <70) increased from 26% to 36%. Compared with period I, in period II there were decreased rates of death (odds ratio [OR]: 0.3; 95% confidence interval [CI]: 0.2-0.4) and increased rates of survival with impairment (OR: 2.3; 95% CI: 1.7-3.3) but also increased rates of survival without impairment (OR: 1.7; 95% CI: 1.3-2.2). Compared with period I, for every 100 infants with birth weights of 500 to 999 g born in period II, 18 additional infants survived, of whom 7 were unimpaired and 11 were impaired.

CONCLUSIONS

The improved survival rates in the 1990s occurred with an increased risk of significant neurodevelopmental impairment. Prospective parents of extremely low birth weight infants should be advised of this substantial risk, to facilitate decision-making in the delivery room.

Follow-up at 15 years of preterm infants from a controlled trial of moderately early dexamethasone for the prevention of chronic lung disease

OBJECTIVE

Postnatal dexamethasone treatment of ventilator-dependent preterm infants results in rapid improvement in lung function and reduction in chronic lung disease. However, limited data are available on long-term outcomes after such therapy. We studied growth, neurodevelopmental, and pulmonary outcomes at adolescence in children who had participated in a double-blind, placebo-controlled trial of dexamethasone beginning at 2 weeks of age for the prevention of chronic lung disease.

METHODS

Thirty-six infants (birth weight < or =1250 g and gestational age < or =30 weeks) who were dependent on mechanical ventilation at 2 weeks of age received a 42-day course of dexamethasone, an 18-day course of dexamethasone, or saline placebo. Twenty-two children survived to 15 years (69% of the 42-day dexamethasone group, 67% of the 18-day dexamethasone group and 45% of the control group), and all were evaluated. Intact survival was defined as survival with normal neurologic examination, IQ >70, and receiving education in the regular classroom.

RESULTS

There were no differences among groups for growth or incidence of neurologic abnormalities. The mean IQ for the 42-day dexamethasone group was 85 +/- 10 compared with 60 +/- 20 for the 18-day dexamethasone group and 73 +/- 23 for the control group. All children in the 42-day dexamethasone group were receiving education in the regular classroom compared with only 50% of the 18-day dexamethasone group and 40% of the control group. As a result, intact survival was significantly greater for the 42-day dexamethasone group (69%) than for either the 18-day dexamethasone group (25%) or the control group (18%). Pulmonary function was significantly better for the 42-day dexamethasone group compared with the 18-day dexamethasone group (eg, forced expiratory volume in 1 second: 90 +/- 16 vs 71 +/- 15% predicted, respectively).

CONCLUSION

A 42-day course of dexamethasone therapy beginning at 2 weeks of age in preterm infants who are at high risk for severe chronic lung disease was associated with improved long-term neurodevelopmental outcome. Although additional research is needed to establish the optimal steroid preparation, dosage, and duration of therapy, these data support the view that moderately early (beginning at 1-2 weeks) corticosteroid treatment is advantageous for a select group of ventilator-dependent preterm infants.

Impact of postnatal systemic corticosteroids on mortality and cerebral palsy in preterm infants: effect modification by risk for chronic lung disease

OBJECTIVE

In preterm infants, chronic lung disease (CLD) is associated with an increased risk for cerebral palsy (CP). However, systemic postnatal corticosteroid therapy to prevent or treat CLD, although effective in improving lung function, may cause CP. The objective of this study was to determine the effect of systemic postnatal corticosteroid treatment on death and CP and to assess any modification of effect arising from risk for CLD.

METHODS

Randomized, controlled trials of postnatal corticosteroid therapy for prevention or treatment of CLD in preterm infants that reported rates of both mortality and CP were reviewed and their data were synthesized. Twenty studies with data on 1721 randomized infants met eligibility criteria. The relationship between the corticosteroid effect on the combined outcome, death or CP, and the risk for CLD in control groups was analyzed by weighted meta-regression.

RESULTS

Among all infants who were randomized, a significantly higher rate of CP after corticosteroid treatment (typical risk difference [RD]: 0.05; 95% confidence interval [CI]: 0.02, 0.08) was partly offset by a nonsignificant reduction in mortality (typical RD: -0.02; 95% CI: -0.06 to 0.02). Consequently, there was no significant effect of corticosteroid treatment on the combined rate of mortality or CP (typical RD: 0.03; 95% CI: -0.01 to 0.08). However, on meta-regression, there was a significant negative relationship between the treatment effect on death or CP and the risk for CLD in control groups. With risks for CLD below 35%, corticosteroid treatment significantly increased the chance of death or CP, whereas with risks for CLD exceeding 65%, it reduced this chance.

CONCLUSIONS

The effect of postnatal corticosteroids on the combined outcome of death or CP varies with the level of risk for CLD.

Minor neurological dysfunction, cognitive development, and somatic development at the age of 3 to 7 years after dexamethasone treatment in very-low birth-weight infants

The objective of this study was to assess minor neurological dysfunction, cognitive development, and somatic development after dexamethasone therapy in very-low-birthweight infants. Thirty-three children after dexamethasone treatment were matched to 33 children without dexamethasone treatment. Data were assessed at the age of 3-7 years. Dexamethasone was started between the 7th and the 28th day of life over 7 days with a total dose of 2.35 mg/kg/day. Exclusion criteria were asphyxia, malformations, major surgical interventions, small for gestational age, intraventricular haemorrhage grades III and IV, periventricular leukomalacia, and severe psychomotor retardation. Each child was examined by a neuropediatrician for minor neurological dysfunctions and tested by a psychologist for cognitive development with a Kaufman Assessment Battery for Children and a Draw-a-Man Test. There were no differences in demographic data, growth, and socio-economic status between the two groups. Fine motor skills and gross motor function were significantly better in the control group (p<0.01). In the Draw-a-Man Test, the control group showed better results (p<0.001). There were no differences in development of speech, social development, and the Kaufman Assessment Battery for Children. After dexamethasone treatment, children showed a higher rate of minor neurological dysfunctions. Neurological development was affected even without neurological diagnosis. Further long-term follow-up studies will be necessary to fully evaluate the impact of dexamethasone on neurological and cognitive development.

Clinical measures to preserve cerebral integrity in preterm infants

Impaired psychomotor development, often anteceded by major intraventricular hemorrhage or periventricular leukomalacia, constitutes the most important long-term morbidity of very preterm infants. We reviewed randomized controlled trials aimed at reducing the incidence of brain damage, as detected by ultrasound, or neurodevelopmental impairment during follow-up of preterm infants. Preliminary reports of reduced rates of intraventricular hemorrhage obtained with administration of fresh frozen plasma, ethamsylate, phenobarbitone, or morphine have not been confirmed in subsequent larger trials. Early administration of indomethacin may reduce intraventricular hemorrhage without affecting long-term outcome. Pancuronium, inositol, and vitamin E decreased intraventricular hemorrhage rates but later psychomotor development was not examined. Thyroxin supplementation failed to improve neurodevelopmental outcome while protein enrichment of formula and individualized developmental care appear to be beneficial. The largest reductions in cerebral palsy and neurodevelopmental impairment were achieved by avoidance of postnatal steroids. This finding emphasizes the need to include these late endpoints in any randomized trial involving preterm infants.

Corticothérapie post-natale chez le prématuré : bénéfices et risques

This review examines the risk/benefit ratio of postnatal steroid treatment in preterm infants and correlates epidemiological data with special emphasis on experimental evidence concening the impact of steroid on brain development. With all regimens, steroid treatment consistently reduced the need for assisted ventilation at 28 days of postnatal age or at term. However, neither oxygen at term nor neonatal mortality has been decreased by this treatment. Conversely, respiratory benefits should be weighed against several adverse effects: hyperglycemia, hypertension, gastrointestinal bleeding or perforation, increased risk of cerebral palsy. The impact of dexamethasone on brain development and risk factors of white matter damage could be involved in the association between postnatal steroid treatment and neurological impairment in treated infants. Injectable preparations of dexamethasone contain sulphiting preservatives which could account for the alterations in neuronal maturation observed in animal models. Early use of dexamethasone should especially be avoided for postnatal steroid treatment in premature infants. Other glucocorticoids as alternatives to dexamethasone need to be evaluated in appropriate and large controlled trials with long term follow up.

Injectable dexamethasone administration enhances cortical GABAergic neuronal differentiation in a novel model of postnatal steroid therapy in mice

Injectable dexamethasone (DXM) is widely used during the postnatal period in premature infants. However, this treatment has been associated with an increased incidence of neuromotor disorders. Few studies have directly addressed the impact of DXM therapy on neuronal differentiation. We used a murine model of postnatal steroid therapy in which mouse pups aged 3 and 4 postnatal days (P) received intraperitoneal injections of 1 mg . kg(-1) . 12 h(-1) of an injectable preparation that contained DXM and sulfites (DXM), pure DXM, or sulfites. The animals were weighed before they were killed on P5, P10, or P21, and their brains were investigated by immunohistochemistry with markers for neuronal differentiation. DXM administration was associated with a 20-30% reduction in body and brain weight gains and in cortical thickness on P5 and P10. gamma-Amino-butyric acid+ (GABA+) interneuron density was significantly increased (+50%) in the cerebral cortex of the animals given injectable DXM on P5 to P21 compared with controls (p < 0.01). In parallel, the density of cortical neurons expressing two interneuron markers (calbindin 28-kD and calretinin) increased significantly. These alterations occurred with injectable DXM but not with pure DXM or sulfites alone. In contrast, none of the study treatments modified the expression of other markers for neuronal transmission or axon myelination. In the animals that were given injectable DXM, cleaved caspase 3 antibody showed increased neuronal cell death, but calbindin antibody did not. In conclusion, in a murine model of postnatal steroid therapy, injectable DXM induced a selective increase in GABAergic neurons in the cerebral cortex.

Management of Bronchopulmonary Dysplasia in Infants

Bronchopulmonary dysplasia (BPD) is a common cause of morbidity and mortality in preterm neonates and at present its management is unclear. Over the past three decades there has been a growing use of corticosteroids in the postnatal period; first for the treatment and then, more recently, for the prevention of BPD. The first published use of corticosteroids to treat neonatal lung disease was in 1956; however, it was only in the 1980s and 1990s that their use in neonates became commonplace. Concerns about their long-term neurodevelopmental consequences arose in the late 1990s when follow-up of randomised controlled trials indicated an increased risk of cerebral palsy after postnatal dexamethasone exposure. Dexamethasone has been the most frequently used corticosteroid in neonatal units, although others, including hydrocortisone, prednisolone and methylprednisolone, have been studied, as have inhaled corticosteroids. Systematic reviews indicate that systemic corticosteroids improve respiratory function in the short term and expedite extubation in preterm neonates. However, there is a high risk of hypertension, hyperglycaemia and gastrointestinal complications in corticosteroid-treated neonates and, if administered in the first 4 days of life, an association with long-term neurodevelopmental delay. There should be emphasis on prevention of BPD by reducing the risk factors associated with its development. There is no role for use of corticosteroids in the first 4 days of life as the high risk of long-term adverse effects outweighs any likely short-term benefits. Corticosteroid use should be limited to exceptional clinical circumstances, such as a ventilator-dependent infant after the second week of life who cannot be weaned from ventilation and whose condition is worsening. If used, they should be prescribed at the lowest effective dose for the shortest possible time. Further randomised trials of low-dose corticosteroids given after the first week of life are warranted and should assess both short- and long-term outcomes.

Fetal and neonatal inflammatory response and adverse outcome

This article will define the concept of fetal/neonatal inflammatory response, and examine the complex interaction between inflammation and neurotoxicity. There appear to be important interactions between infection/inflammation and hypoxia-ischaemia leading to cytokine release and subsequent brain injury. This article will also define adverse outcome and summarize the complexities inherent to neurodevelopmental assessment. Finally, this article will investigate the currently available evidence suggesting a link between inflammatory response and adverse neurodevelopmental outcome, and focus on those variables that need further study: timing and nature of the infectious/inflammatory process; established and new anti-insult strategies; morbidity in organs other than the brain; genetic influences; and environmental factors.

Neonatal dexamethasone treatment affects social behaviour of rats in later life

Synthetic glucocorticoids, like dexamethasone (DEX), have been frequently administered to premature infants to prevent chronic lung disease. Major concern has arisen about the long-term neurodevelopmental sequelae of this DEX treatment. In the present study, we found that neonatal DEX treatment in rats, using a treatment protocol resembling the one used in the clinical situation, increased social play behaviour in juvenile life. Furthermore, neonatal DEX treatment increased sexual motivation and intromission behaviour in the bi-level chamber, decreased submissive behaviour during an aggressive encounter, and impaired social memory in adulthood. These changes in social behaviour are not due to a general behavioural impairment since anxiety behaviour in the elevated plus maze and exploratory activity in the open-field were not affected in DEX rats. In addition, DEX rats showed no alteration in the total duration of social interest or social activity during a social interaction test. These effects of neonatal DEX treatment on behaviour later in life likely result from neurodevelopmental actions of the hormone since we found no differences in received maternal care between DEX and SAL treated pups. Together these results indicate that neonatal treatment with DEX selectively alters aspects of the behavioural response to social challenges. Thus, neonatal DEX treatment may lead to inappropriate interactions with conspecifics later in life. These data therefore warrant investigation of lasting and potentially adverse effects of treatment of human neonates with DEX on social functioning.

Perinatal corticosteroids: a review of the research. Part II: Postnatal administration

Postnatal corticosteroids are often administered during the neonatal intensive care unit stay to reduce the risk and severity of chronic lung disease (CLD) in preterm infants. In 2002, the American Academy of Pediatrics Committee on Fetus and Newborn and the Canadian Paediatric Society Fetus and Newborn Committee jointly advised against the routine use of systemic dexatmethasone for the prevention of CLD in very low birth weight infants. The objective of this review is to present evidence-based research and expert opinion to provide the neonatal clinician with current information regarding dexamethasone use with premature infants. This article serves to inform neonatal clinicians about the benefits and potential adverse neurosensory risks of this treatment option.

Postnatal glucocorticoid exposure alters the adult phenotype

We examined the effect of six doses of dexamethasone (Dex) administered daily (2–7 days of age) to postnatal rats on body weight gain, food and water intake, peripheral hormonal/metabolic milieu, and hypothalamic neuropeptides that regulate food intake. We observed a Dex-induced acute (3 days of age) suppression of endogenous corticosterone and an increase in circulating leptin concentrations that were associated with a decrease in body weight in males and females. Followup during the suckling, postsuckling, and adult stages (7–120 days of age) revealed hypoleptinemia in males and females, and hypoinsulinemia, a relative increase in the glucose-to-insulin ratio, and a larger increase in skeletal muscle glucose transporter (GLUT 4) concentrations predominantly in the males, reflective of a catabolic state associated with a persistent decrease in body weight gain. The increase in the glucose-to-insulin ratio and hyperglycemia was associated with an increase in water intake. In addition, the changes in the hormonal/metabolic milieu were associated with an increase in hypothalamic neuropeptide Y content in males and females during the suckling phase, which persisted only in the 120-day-old female with a transient postnatal decline in α-melanocyte-stimulating hormone and corticotropin-releasing factor. This increase in neuropeptide Y (NPY) during the suckling phase in males and females was associated with a subsequent increase in adult food intake that outweighed the demands of body weight gain. In contrast to the adult hypothalamic findings, cerebral ventricular dilatation was more prominent in adult males. We conclude that postnatal Dex treatment causes permanent sex-specific changes in the adult phenotype, setting the stage for future development of diabetes (increased glucose:insulin ratio), obesity (increased NPY and food intake), and neurological impairment (loss of cerebral volume).

A randomized trial of two dexamethasone regimens to reduce side-effects in infants treated for chronic lung disease of prematurity

OBJECTIVE

Dexamethasone has been widely used to reduce the incidence of chronic lung disease in preterm infants. However side-effects are common, and the ideal dose of dexamethasone has not been identified. We aimed to determine whether an individualized course of dexamethasone given to preterm babies at risk of chronic lung disease reduced the total dose of dexamethasone administered and reduced side-effects compared with a standard 42-day course.

METHODS

Thirty-three infants in a regional neonatal unit with a birthweight of < or =1250 g who required mechanical ventilation at 7 days of age were randomly assigned to a 42-day course of dexamethasone or an individualized course tailored to their respiratory status. The primary outcome was linear growth at 36 weeks corrected gestational age.

RESULTS

Infants in the individualized course received a 40% lower total dose of dexamethasone. However, there was no difference between the two groups in linear growth or in the incidence of any other side-effects of treatment. There was also no difference in respiratory status or neurodevelopmental outcome.

CONCLUSION

The individualized course of dexamethasone used in this study reduced the total dose of dexamethasone administered but did not significantly reduce side-effects of treatment or alter outcome in infants at risk of chronic lung disease.

Modification of cord blood IL-6 production with IgM enriched human immunoglobulin in term and preterm infants

Pro-inflammatory cytokines contribute significantly to the morbidity of premature infants. IL-6 and IL-8 are involved in the pathogenesis of pulmonary and cerebral tissue injury. The effect of human immunoglobulin preparations on cytokine production in preterm infants has not been studied. We investigated the influence of immunoglobulin on LPS stimulated IL-6 and IL-8 production in cord blood of healthy preterm neonates. Ten non-infected preterm infants delivered by cesarean section and 5 healthy term neonates were included. In the preterm infants, significant IL-6 production was observed in the absence of immunoglobulin after 4 h [median 113 (39-725) pg/ml], 8 h [375 (234-1795) pg/ml] and 12 h [360 (248-2765) pg/ml] of LPS incubation. IL-6 concentrations were significantly lower after incubation with LPS+immunoglobulin after 4 h [median 38 (5-568) pg/ml; p=0.005], 8 h [178 (10-1830) pg/ml; p=0.001] and 12 h [182 (29-2530) pg/ml; p=0.002]. Cultures from term infants produced IL-6 levels approx. 4 times of those from premature infants unaffected by immunoglobulin. IL-8 production also correlated to gestational age and was not affected by immunoglobulin in both groups. Human immunoglobulin preparation may modify IL-6 production in cord blood cultures from premature infants.

Center differences and outcomes of extremely low birth weight infants

OBJECTIVE

Previous multicenter studies have shown significant center differences in neonatal characteristics and morbidities. This study evaluated center differences in outcome at 18 to 22 months among extremely low birth weight (ELBW; 401-1000 g) infants after adjusting for demographics and antenatal interventions, and it identified neonatal interventions associated with outcome differences.

METHODS

We assessed the outcome of 2478 liveborn infants who were admitted in 1993 and 1994 to the 12 centers of the Neonatal Research Network of the National Institute of Child Health and Human Development; 1483 (60%) infants survived to 18 to 22 months, and 1151 (78%) had comprehensive evaluations. Logistic regression analyses were performed to identify center differences and the association of 4 neonatal interventions--active resuscitation, postnatal steroids, ventilator treatment for < or =27 days, and full enteral feedings < or =24 days--with adverse outcomes (cerebral palsy, low Bayley scores, and neurodevelopmental impairment [NDI]), after adjusting for demographics and antenatal interventions.

RESULTS

Using bivariate analyses, significant center differences were identified for mortality, antenatal and postnatal interventions, social and environmental variables, neonatal morbidities, and neurodevelopmental outcomes for the 12 centers. After adjustment for maternal and infant demographics and antenatal interventions, the percentage of ELBW infants who had died or had NDI at 18 to 22 months ranged from 52% to 85%. Active resuscitation and postnatal steroids were associated with increases of NDI of 11.8% and 19.3%, whereas shorter ventilation support and shorter time to achieve full enteral feeds were associated with decreases in NDI of 20.7% and 17.3%, respectively.

CONCLUSION

There are large and disturbing differences among centers in outcomes at 18 to 22 months after adjusting for demographic and antenatal interventions. Center differences in postnatal interventions associated with differences in outcome can provide hypotheses for testing in clinical trials to improve outcome.

Outcomes at school age after postnatal dexamethasone therapy for lung disease of prematurity

BACKGROUND

We studied the outcomes at school age in children who had participated in a double-blind, placebo-controlled trial of early postnatal dexamethasone therapy (initiated within 12 hours after birth) for the prevention of chronic lung disease of prematurity.

METHODS

Of the 262 children included in the initial study, 159 lived to school age. Of these children, 146 (72 in the dexamethasone group and 74 in the control group) were included in our study. All the infants had had severe respiratory distress syndrome requiring mechanical ventilation shortly after birth. In the dexamethasone group, 0.25 mg of dexamethasone per kilogram of body weight was given intravenously every 12 hours for one week, and then the dose was tapered. We evaluated the children's growth, neurologic and motor function, cognition, and school performance.

RESULTS

Children in the dexamethasone group were significantly shorter than the controls (P=0.03 for boys, P=0.01 for girls, and P=0.03 for all children) and had a significantly smaller head circumference (P=0.04). Children in the dexamethasone group had significantly poorer motor skills (P<0.001), motor coordination (P<0.001), and visual-motor integration (P=0.02). As compared with the controls, children in the dexamethasone group also had significantly lower full IQ scores (mean [+/-SD], 78.2+/-15.0 vs. 84.4+/-12.6; P=0.008), verbal IQ scores (84.1+/-13.2 vs. 88.4+/-11.8, P=0.04), and performance IQ scores (76.5+/-14.6 vs. 84.5+/-12.7, P=0.001). The frequency of clinically significant disabilities was higher among children in the dexamethasone group than among controls (28 of 72 [39 percent] vs. 16 of 74 [22 percent], P=0.04).

CONCLUSIONS

Early postnatal dexamethasone therapy should not be recommended for the routine prevention or treatment of chronic lung disease, because it leads to substantial adverse effects on neuromotor and cognitive function at school age.

Postnatal steroid treatment and brain development

This review examines the risk/benefit ratio of postnatal steroid treatment in preterm infants and correlates epidemiological data with experimental evidence on the effect of glucocorticosteroids on brain development.

High incidence of nephrocalcinosis in extremely preterm infants treated with dexamethasone

BACKGROUND

The use of postnatal corticosteroids to treat or prevent chronic lung disease is common in very preterm infants. Medullary nephrocalcinosis has been noted as a possible side effect.

OBJECTIVE

This prospective study was designed to assess the incidence of nephrocalcinosis in extremely preterm infants exposed to dexamethasone.

PATIENTS AND METHODS

A prospective study of extremely preterm infants, recruited to a randomized trial of dexamethasone treatment for chronic lung disease, was initiated. Infants had US of the renal tract scheduled on entry into the study, at day 28 and at discharge or at the corrected gestational age of 36 weeks.

RESULTS

Thirty-three infants were enrolled in the study. Birth weight ranged between 440 and 990 g and gestation between 24 and 28 weeks. Nine infants died and six had incomplete data. Because there was no difference in incidence of calcification between those on the short course and those on the long course of dexamethasone, analysis was made on the entire cohort. One infant had nephrocalcinosis at the time of the initial US examination on day 26 of life. By day 28, nephrocalcinosis was present in 31% of those with complete data. By discharge, or corrected gestational age of 36 weeks, US evidence of nephrocalcinosis was present in 15 (83%) of 18 infants. All infants had at least one course of an aminoglycoside antibiotic during the study. All infants had parenteral nutrition. Only four infants received furosemide more regularly than single doses. The longest course was 10 days, received by an infant who did not develop nephrocalcinosis.

CONCLUSION

The incidence of nephrocalcinosis is high in this group of sick, extremely preterm infants. Dexamethasone may be a factor in the development of nephrocalcinosis. Future research should focus on the natural history of nephrocalcinosis in extremely preterm infants.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Systemic glucocorticoids have been widely prescribed for use in infants and young children with acute viral bronchiolitis but the actual benefit of this intervention requires clarification.

OBJECTIVES

To systematically review the evidence on the effectiveness of systemic glucocorticoids for the treatment of infants and young children with acute viral bronchiolitis.

SEARCH STRATEGY

Multiple strategies were incorporated to maximize identification of suitable studies. The following databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2003); MEDLINE (January 1966 to September 2003); Current Contents (1998 to 2000); EMBASE (January 1990 to September 2003); and Sci Search. Handsearches through cited references and contacts with experts were also used.

SELECTION CRITERIA

Only randomised controlled trials (RCT) were eligible for inclusion. Studies were included if participants were diagnosed with acute viral bronchiolitis and treated with systemic (oral, intramuscular or intravenous) corticosteroids. Three reviewers independently selected potentially relevant articles. Four reviewers evaluated these studies, determined eligibility and assessed the methodological quality of each RCT.

DATA COLLECTION AND ANALYSIS

The primary outcome of interest was length of hospital stay (LOS). Secondary outcomes were: respiratory rate, haemoglobin oxygen saturation, and hospital admission and revisit rates. Data were extracted independently by the four reviewers and the results compiled and compared. Two reviewers reassessed studies to clarify points of discrepancy in the data extraction and database entry processes. Missing data were requested from the authors or calculated from other data presented in the study report.

MAIN RESULTS

There was complete agreement on the inclusion of 13 trials and the exclusion of five studies. Two main study recruitment groups were identified: a) infants and young children within the first 48 hours of hospitalisation (10 trials), and b) outpatient infants and young children who were randomised from the emergency department and who may nor may not have required hospital admission (three trials).A total of 1,198 children aged 0 to 30 months were treated with the equivalent of 0.5 to 10 mg/kg of systemic prednisone for two to seven days. Outcomes of interest were not measured in each RCT. In the pooled analysis of seven trials, there was a decrease in LOS in treated children of 0.38 days (95% confidence interval (CI) -0.81 to 0.05), indicating no significant difference between treatment groups. In the pooled analysis of eight trials, the day three clinical score measured: a standard mean difference (SMD) of -0.20 (95% CI -0.73 to 0.32), indicating no difference between treatment groups. Subgroup analyses for base LOS and clinical score outcomes were performed on infants who were a) less than 12 months of age, b) all respiratory syncytial virus (RSV) positive, c) treated with less than 6 mg/kg of prednisone equivalent throughout the illness and d) first-time wheezers. These were limited by the small number of studies in each subgroup. Hospital admission rates were examined in three trials and no difference was seen between treatment groups (odds ratio (OR) 1.05 (95% CI 0.23 to 4.87). Readmission rates were reported in six studies; with no significant differences between treatment groups. Hospital revisit rates were reported in three studies, with a significant difference between treatment groups reported in one study only. The respiratory rate and haemoglobin oxygen saturation were reported descriptively in six RCTs; no differences were found between groups. Co-interventions (oxygen, supportive fluids and bronchodilators) were used similarly between treatment groups in all RCTs.

REVIEWERS' CONCLUSIONS

No benefits were found in either LOS or clinical score in infants and young children treated with systemic glucocorticoids as compared to placebo. There were no differences in these outcomes between treatment groups; either in the pooled groups; either in the pooled analysis or in any of the sub analyses. Among the three studies evaluating hospital admission rates following the initial hospital visit there was no difference between treatment groups. There were no differences found in respiratory rate, haemoglobin oxygen saturation, hospital revisit or readmission rates. Subgroup analyses were significantly limited by the low number of studies in each comparison. Marked study heterogeneity and occasionally conflicting direction of benefit between trials suggests that these results should be interpreted with caution. Specific data on the harm of corticosteroid therapy in this patient population are lacking. Available evidence suggests that corticosteroid therapy is not of benefit in this patient group.

[Neonatal lupus syndrome: review of the literature]

PURPOSE

Neonatal lupus syndrome include skin lesions, hematological and hepatic disorders, and congenital heart block (CHB) in the absence of severe cardiac malformation. This rare disorder is closely linked to transplacental transport of anti-SSA/Ro and anti-SSB/La maternal antibodies.

CURRENT KNOWLEDGE AND KEY POINTS

The prevalence of CHB in newborns of anti-Ro/SSA positive women with known connective tissue disease is 2% and the risk of recurrence ranges from 10 to 17%. Skin and systemic lesions are transient, whereas CHB is definitive and is associated with significant morbidity and mortality (estimated at 16-19%). A pacemaker must be implanted in 2/3 of cases. Myocarditis may be associated or may appeared secondarily. Mothers of children with CHB are usually asymptomatic or have Gougerot-Sjögren, or undifferentiated connective tissue disease. Mothers of children with cutaneous manifestations may present with more severe disease and systemic lupus erythematosus. In anti-Ro/SSA positive pregnant women, echocardiograms should be performed at least every 2 weeks from 16 to 24 weeks gestation. Electrocardiogram should be performed for all children.

FUTURE PROSPECTS AND PROJECTS

The efficiency of prophylactic treatment of CHB is not established. Therapy for CHB detected in utero is not standardized and involves fluorinated steroids (especially betamethasone).

Current perspectives on the prevention and management of chronic lung disease in preterm infants

Chronic lung disease (CLD) or bronchopulmonary dysplasia is a recognized sequel of preterm birth. With improving survival of infants at lower gestational ages, the incidence is on the rise. Pathological features of CLD include alveolar maldevelopment, with or without areas of pulmonary fibrosis. Assisted ventilation, infection/inflammation, oxygen administration, and fluid overload are the major risk factors in the evolution of CLD.Interventions, including the treatment of maternal infection, administration of prenatal glucocorticoids, and postnatal surfactant replacement therapy, improve the survival of preterm infants; however, their effect on CLD is difficult to determine. Strategies that have been effective in reducing CLD are the administration of retinol (vitamin A), high frequency oscillatory ventilation, and administration of glucocorticoids. Previous concerns regarding neurological problems associated with high frequency ventilation have not been substantiated in recent studies. Current recommendations do not advise the routine use of glucocorticoids due to concerns regarding long-term neurodevelopment. Therapies that were found to be ineffective in reducing the incidence of CLD include prenatal thyrotropin, cromolyn sodium (sodium cromoglycate), alpha-1 antitrypsin, superoxide dismutase, tocopherol (vitamin E), ascorbic acid (vitamin C), allopurinol, ambroxol, inositol, inhaled bronchodilators, and fluid restriction. Strategies that may be effective in reducing lung injury and subsequent CLD include avoiding assisted ventilation, lung protective ventilatory maneuvers, permissive hypercapnia, prevention of infection, early aggressive nutrition, and the treatment of a patent ductus arteriosus. The use of inhaled glucocorticoids improves pulmonary dynamics but long-term effects are unknown. The management of infants with established CLD has not been studied adequately, and the role of various ventilatory strategies for infants with established CLD is not clear. Adequate oxygenation should be maintained to prevent hypoxic episodes. Diuretics are helpful during acute decompensation; however, their long-term impact has not been well studied. Provision of adequate nutrition, immunization (routine and against respiratory syncytial virus), follow-up, and monitoring are the key elements in the long-term management of infants with CLD. Future research priorities should be to identify strategies to prevent/treat inflammation and promote the healing processes in the injured lung. The long-term effects of lung-protective ventilation strategies need to be studied.

State of the Science: Achievements and Challenges Across the Spectrum of Care for Preterm Infants

The spectrum of care for preterm infants includes the perinatal and immediate neonatal periods, the initial hospitalization period including neonatal intensive care, transition to discharge, and from discharge through the first year of life. Care issues are sometimes lifelong. Advances and achievements of the past 20 years, particularly during the perinatal period and in neonatal intensive care, have resulted in significant increases in survivability of even the smallest and least mature infants. Challenges remain, particularly in establishing evidence-based standards of nursing practice in areas such as transition to oral feedings, breastfeeding in the intensive-care nursery, and developmentally based care, and in reducing short- and long-term morbidities in children born prematurely. This article illustrates achievements and challenges across the spectrum of care for preterm infants in the 1st year of life.

Developments in neonatal technology continue to improve infant outcomes

The past 20 years have yielded little success in reducing prematurity rates or decreasing the major morbidities of premature infants. Determination of interventions to decrease prematurity rates, and the development of methods to reduce premature neurologic damage, are the challenges for the next 20 years. With the advent of genetic analysis and the ability to study environmental and genetic interactions, we may be on the threshold of another significant decrease in mortality and morbidity in the premature infant.

Brainstem maturation after antenatal steroids exposure in premature infants as evaluated by auditory brainstem-evoked response

OBJECTIVE

Antenatal steroids result in fetal lung maturation, but may retard brain development. Auditory brainstem-evoked response (ABR) is a noninvasive assessment of brainstem maturation. The objective of this study was to determine if antenatal steroids affect brainstem maturation in infants </=32 weeks gestational age (GA).

DESIGN/METHODS

Bilateral monaural ABR were performed within the first 24 hours using 80 db nHL unfiltered click stimuli at a repetition rate of 39.9/seconds. ABR waveforms were categorized into Response Types based on response replicability and peak identification. Absolute wave latencies and interpeak latencies were measured when applicable. Data were collected for antenatal steroid exposure, mode of delivery, chorioamnionitis in utero, exposure to illicit drugs, exposure to magnesium sulfate, mechanical ventilation and 5 minute Apgar score <5 minute. Infants with TORCH infections, unstable conditions, and chromosomal disorders were excluded.

RESULTS

Of 186 infants studied, 130 received antenatal steroids. Data were analyzed in 2 week GA intervals. There was a significant difference (P<0.05) in race (29 vs 39% African-American), birth weight (1231 vs 1416 gm) and use of magnesium sulfate (60 vs 32%) among infants who did and did not receive antenatal steroids, respectively. There was no significant difference in the other parameters measured. Even after controlling for confounding variables, there was no difference between absolute wave latencies or interpeak latencies between groups at either 28 to 29 weeks' or 30 to 31 weeks' postmenstrual age. There was no significant difference in frequency distribution of ABR waveform Response Types between groups.

CONCLUSIONS

Antenatal steroids have neither a deleterious nor beneficial effect on brainstem maturation as measured by ABR in infants at </=32 weeks GA.

Follow-up data their use in evidence-based decision-making

Experience with certain perinatal interventions, such as supplemental oxygen and dexamethasone, leads to the conclusion that follow-up data are needed to be well informed about the safety of certain perinatal interventions. Experience with indomethacin suggests that follow-up data also are regarded by some clinicians as a necessary aspect of evidence about effectiveness. Ideally, clinical trials of perinatal interventions might involve collection of data about neonatal predictors of outcome (such as a neuroimaging study and a standardized neurologic assessment); several developmental and neurologic assessments before school entry; a comprehensive evaluation of the child's cognitive function, behavioral competencies, and academic performance at 7 to 8 years of age; serial detailed assessments of the family psychosocial functioning; and an inventory of resources available for the child. Many clinical trials have not included follow-up after the neonatal period, and in such cases information about the effect of the intervention on participants' HRQL is incomplete. The approach taken in several recent trials, in which the outcome of interest is neurodevelopmental outcome at 18 months, attempts to strike a balance between a theoretical ideal (a comprehensive, longitudinal follow-up through school age) and a follow-up regimen that is not prohibitively expensive. Such trials include follow-up during the first 1 to 3 years of life, when major disabilities can be identified reliably, thereby providing moderately informative data about participants' eventual quality of life, related to the presence or absence of major disability. If, however, there is reason to suspect that the intervention has effects on the developing brain, follow-up after school entry may provide additional evidence pertinent to the risks and benefits of the intervention.

Preterm outcomes research: a critical component of neonatal intensive care

While early preterm outcome studies described the lives of preterm survivors to justify the efforts required to save them, subsequent studies demonstrated their increased incidence of cerebral palsy, mental retardation, sensory impairments, minor neuromotor dysfunction, language delays, visual-perceptual disorders, learning disability and behavior problems compared to fullterm controls. Because infants born at the lower limit of viability require the most resources and have the highest incidence of neurodevelopmental disability, there is concern that resources have gone primarily to neonatal intensive care and are not available for meeting the followup, health, educational and emotional needs of these fragile infants and their families. Despite many methodological concerns, preterm outcome studies have provided insight into risk factors for and causes of CNS injury in preterm infants. Nevertheless, it remains difficult to predict neurodevelopmental outcome for individual preterm infants. Perinatal and neonatal risk factors are inadequate proxies for neurodevelopmental disability. Recent randomized controlled trials with one to five year neurodevelopmental followup have provided valuable information about perinatal and neonatal treatments. Recognizing adverse longterm neurodevelopmental effects of pharmacological doses of postnatal steroids is a sobering reminder of the need for longterm neurodevelopmental followup in all neonatal randomized controlled trials. Ongoing longterm preterm neurodevelopmental studies, analysis of changes in outcomes over time and among centers, and evaluation of the longterm safety, efficacy and effectiveness of many perinatal and neonatal management strategies and proposed neuroprotective agents are all necessary for further medical and technological advances in neonatal intensive care.

Patterns of motor disability in very preterm children

Motor development in very preterm children differs in several important ways from that of children born at full term. Variability is common, although the anatomic and physiologic bases for that variability are often poorly understood. Motor patterns over the first postnatal year may depend on behaviours learned during often long periods of neonatal intensive care. The normal pattern of development may be modified by disturbances of brain function caused both by the interruption of normal brain maturation ex-utero and the superimposition of focal brain injuries following very preterm birth. Abnormal patterns of development over the first year may evolve into clear neuromotor patterns of cerebral palsy or resolve, as "transient dystonias." Cerebral palsy is associated with identified patterns of brain injury secondary to ischaemic or haemorrhagic lesions, perhaps modified by activation of inflammatory cytokines. Cerebral palsy rates have not fallen as might be expected over the past 10 years as survival has improved, perhaps because of increasing survival at low gestations, which is associated with the highest prevalence of cerebral palsy. Children who escape cerebral palsy are also at risk of motor impairments during the school years. The relationship of these impairments to perinatal factors or to neurological progress over the first postnatal year is debated. Neuromotor abnormalities are the most frequent of the "hidden disabilities" among ex-preterm children and are thus frequently associated with poorer cognitive ability and attention deficit disorders. Interventions to prevent cerebral palsy or to reduce these late disabilities in very preterm children are needed.

The potential role for arachidonic and docosahexaenoic acids in protection against some central nervous system injuries in preterm infants

The risk of central nervous, visual, and auditory damage increases from 2/1000 live births in the normal birthweight to > 200/1000 as birthweight falls below 1500 g. Such babies are most likely to be born preterm. Advances in infant care have led to increasing numbers of very-low-birthweight, preterm infants surviving to school age with moderate to severe brain damage. Steroids are one of the current treatments, but they cause significant, long-term problems. The evidence reported here suggests an additional approach to protecting the very preterm infant by supporting neurovascular membrane integrity. The complications of preterm, very-low-birthweight babies include bronchopulmonary dysplasia, retinopathy of prematurity, intraventricular hemorrhage, periventricular leukomalacia, and necrotizing enterocolitis, all of which have a vascular component. Arachidonic acid (AA) and DHA are essential, structural, and functional constituents of cell membranes. They are especially required for the growth and function of the brain and vascular systems, which are the primary biofocus of human fetal growth. Molecular dynamics and experimental evidence suggest that DHA could be the ligand for the retinoid X receptor (RXR) in neural tissue. RXR activation is an obligatory step in signaling to the nucleus and in the regulation of gene expression. Very preterm babies are born with minimal fat stores and suboptimal circulating levels of these nutrients. Postnatally, they lose the biomagnification of the proportions of AA and DHA by the placenta for the fetus. No current nutritional management repairs these deficits. The placental biomagnification profile highlights AA rather than DHA. The resultant fetal FA profile closely resembles that of the vascular endothelium and not the brain. Without this nourishment, cell membrane abnormalities would be predicted. We present a scientific rationale for a common pathogenic process in the complications of prematurity.

Cognitive development at 5.5 years of children with chronic lung disease of prematurity

BACKGROUND

Preterm infants with chronic lung disease (CLD) had impaired cognitive development and poorer eye-hand coordination at 10 months of age.

AIMS

To study whether this effect of CLD persisted until school age and whether the severity of CLD affected outcome.

METHOD

Cognition and visual-motor skills were examined (Wechsler preschool and primary scale of intelligence, and tests from the Nepsy scale) in 60 very preterm children, without intraventricular haemorrhage or periventricular leucomalacia, at 5.5 years of age. Thirty two children suffered from CLD and 28 were controls.

RESULTS

The groups did not differ significantly in cognitive outcome. Children with CLD and controls attained a full scale intelligence quotient (IQ) of 94.4 and 99.1, a verbal IQ of 99.6 and 101.5, and a performance IQ of 90.9 and 96.7 respectively. Similarly, no difference was found in tests of eye-hand control. However, the children with the most severe form of CLD had significantly lower performance (84.8) and full scale(87.6) IQs and worse visual-motor performance than the controls. CLD grade III, together with the need for glasses or lenses, had a significant impact on the explained variance.

CONCLUSIONS

At school age, children born very preterm and who experienced severe CLD had deficits in cognition, visual-motor perception, and performance. The findings suggest a need to consider intervention programmes for such infants.

Corticosteroids in the prevention and management of bronchopulmonary dysplasia

Corticosteroids were first prescribed for preterm neonates to treat respiratory distress syndrome, but they were found to have no beneficial effect in this disorder. About 20 years ago, dexamethasone was first used to treat infants with bronchopulmonary dysplasia who were ventilator dependent after the age of 3 weeks. There were short-term benefits, with an improvement in lung function and a facilitation of endotracheal extubation. During the 1990s, corticosteroid treatment, mainly with dexamethasone in relatively high doses, became very common in neonatal intensive care units. Towards the end of the decade, however, follow-up studies provided evidence of abnormal neurodevelopment, especially in infants treated early (<4 days) with dexamethasone. The precise cause of these neurodevelopmental problems is unclear, but until further evidence has been obtained, the early use of dexamethasone cannot be recommended for preterm infants. This review attempts to provide evidence-based guidelines for postnatal steroid therapy in the management of chronic lung disease.

Alterations in adult rat heart after neonatal dexamethasone therapy

Glucocorticoid treatment in preterm babies to prevent chronic lung disease causes myocardial hypertrophy and increased myocardial protein content. Although these changes are thought to be transient, there is evidence that dexamethasone (DEX) induces permanent myocardial abnormalities as well. We investigated whether a therapeutic course of neonatal DEX in rat pups produces anatomic and biochemical alterations in rat hearts during adult life. Twenty-four rat pups were treated with DEX on d 1, 2, and 3 (0.5, 0.3, and 0.1 micro g/g) of life, with doses proportional to those used in preterm babies. Twenty-four control pups were treated with saline. At d 7, wk 8, or wk 45 (n = 8 per group) rats were killed. The anatomic parameters measured were body weight (Bw, in grams), heart (myocardial) weight (Hw, in milligrams), and the Hw:Bw ratio. Myocardial total protein (Prot) and DNA content were determined, and the Prot:DNA ratio was calculated. Histopathology and morphometry were performed on 45-wk-old rat hearts. In DEX-treated rat pups, at d 7, Bw and Hw were lower and the Hw:Bw ratio was increased. DNA content was lower, Prot higher, and Prot:DNA ratio was increased. In 8-wk-old rats Bw, Hw, DNA content, Prot content or Prot:DNA ratio did not differ between groups, but the Prot:DNA ratio still tended to be higher in DEX-treated rats. In 45-wk-old rats Hw and Hw:Bw ratio were significantly lower and Prot:DNA ratio higher in DEX-treated rats. Histopathologic analysis showed larger cardiomyocyte volume, length, and width, indicating hypertrophy, and increased collagen, indicating early degeneration of individual myocytes. In conclusion, neonatal DEX treatment in rat pups causes a permanent decrease in heart weight, as well as hypertrophy and early degeneration of cardiomyocytes during adulthood.

Cerebral palsy in very preterm infants: new epidemiological insights

The focus of this review is on new insights from recent epidemiological research on cerebral palsy in preterm infants. These include: 1) a better understanding of issues related to diagnosis and classification; 2) new information about the brain abnormalities underlying cerebral palsy in preterm infants; and 3) a better understanding of biological mechanisms that may underlie previously described epidemiological associations. Ongoing efforts to improve the diagnosis and classification of cerebral palsy have been enhanced by findings from serial examinations of cohorts of very preterm infants. Cranial ultrasonography through the anterior fontanelle of very preterm infants has provided information about grossly evident brain damage, found in about one-half of preterm infants who develop cerebral palsy. Insights into the pathophysiologic basis for certain epidemiologic associations have come from studies of experimental brain damage in animals and clinical studies of neurologic disorders in adults. Much of the current epidemiological research into the causes of cerebral palsy in preterm infants has focused on two potential mechanisms of brain damage. One mechanism involves insufficient cerebral perfusion; the other, cytokine-mediated damage, potentially triggered by events such as maternal infection (e.g., intrauterine or periodontal infection), neonatal infection (e.g., sepsis and necrotizing enterocolitis), and neonatal oxygen- or ventilator-induced lung injury. In addition to the preterm infant's increased exposure to such damaging factors, the high frequency of cerebral palsy in these infants might be due, in part, to insufficient levels of developmentally regulated protective substances, such as thyroid hormone and glucocorticoids. Models of causation currently are being investigated using recently developed methods for quantifying, with small quantities of blood, biomolecules that are suspected to either promote or protect against brain damage in the neonate. Clinical investigations now under way can be expected to identify strategies to be tested in clinical trials that could lower the risk of cerebral palsy in very preterm infants.

Glucocorticoid-attenuated response genes induced in the lung during endotoxemia

Cytokines and other mediators whose induction in inflammatory lung disease is attenuated by glucocorticoids are potential targets for development of selective anti-inflammatory treatments. We refer to genes with these regulatory characteristics as glucocorticoid-attenuated response genes, or GARGs. Systematic identification of GARGs has not been attempted previously in vivo. Using an endotoxemia model in adrenalectomized mice, we constructed a subtracted lung library enriched in endotoxemia-induced genes and identified candidate GARGs by differential hybridization screening. Northern analysis confirmed induction in the lung during endotoxemia and attenuation by glucocorticoids of 36 genes of diverse types. The majority were genes of unknown function not previously implicated in the pulmonary response to inflammation, including a new member of a 2'-5'-oligoadenylate synthetase-like family and a novel lung inducible Neuralized-related C3HC4 RING protein. Our results suggest that a full understanding of glucocorticoid effects on lung inflammation will require elucidation of the roles of an extensive network of glucocorticoid-modulated genes.

Glucocorticoid receptors in hippocampal neurons that do not engage proteasomes escape from hormone-dependent down-regulation but maintain transactivation activity

The glucocorticoid receptor (GR) protein is subjected to hormone-dependent down-regulation in most cells and tissues. This reduction in receptor levels that accompanies chronic hormone exposure serves to limit hormone responsiveness and operates at transcriptional, posttranscriptional, and posttranslational levels. The ability of glucocorticoid hormones to trigger GR down-regulation may be not universal, particularly in mature and developing neurons in which conflicting results regarding hormone control of GR protein have been reported. We find that endogenous GR is not down-regulated in the HT22 mouse hippocampal cell line and in primary hippocampal neurons derived from embryonic rats. Because GR has the capacity to be ubiquitylated in HT22 cells, receptor down-regulation must be limited by defects in either targeting of polyubiquitylated receptor to the proteasome or processing of the targeted receptor by the proteasome. Despite the lack of GR down-regulation in the HT22 cells, glucocorticoid-induced transcription from transiently transfected templates is attenuated upon prolonged hormone treatment. This termination of GR transactivation is not due to inefficient nuclear import or nuclear retention of the receptor. Furthermore, GR efficiently exports from HT22 cell nuclei in hormone-withdrawn cells, indicating that the receptor has access to both nuclear and cytoplasmic degradation pathways. Our results suggest that appropriate maturation of proteasomal degradative or targeting activities may be required, particularly in hippocampal neurons, for hormone-dependent down-regulation of GR.