Bronchopulmonary dysplasia and intrauterine growth restriction

Associations between Bronchopulmonary Dysplasia, Insulin-like Growth Factor I and Nutrition

Insulin-like growth factor I (IGF-I) has been suggested as an important factor in the pathogenesis of bronchopulmonary dysplasia (BPD). In turn, nutrition has been associated with IGF-I levels and could be of importance in the pathogenesis of BPD. This study aimed to explore the association between nutrition, the IGF-I axis and the occurrence of BPD. Eighty-six preterm infants (44 male, mean gestational age: 29.0 weeks (standard deviation: 1.7 weeks)) were enrolled in an observational study. Serum IGF-I (µg/L) and insulin-like growth factor binding protein 3 (IGFBP-3; mg/L) were measured at birth and at 2, 4 and 6 weeks postnatal age. BPD was diagnosed at 36 weeks postmenstrual age. Twenty-nine infants were diagnosed with BPD. For every µg/L per week increase in IGF-I, the odds of BPD decreased (0.68, 95% CI 0.48-0.96, corrected for gestational age). The change in IGF-I in µg/L/week, gestational age in weeks and a week of predominant donor human milk feeding were associated with the occurrence of BPD in the multivariable analysis (respectively, OR 0.63 (0.43-0.92), OR 0.44 (0.26-0.76) and 7.6 (1.2-50.4)). IGFBP-3 was not associated with the occurrence of BPD in the multivariable analysis. In conclusion, a slow increase in IGF-I levels and a lower gestational age increase the odds of BPD. Donor human milk might increase the odds of BPD and should be further explored.

Appropriate Delivery Timing in Fetuses with Fetal Growth Restriction to Reduce Neonatal Complications: A Case-Control Study in Romania

(1) Background: The main challenge in cases of early onset fetal growth restriction is management (i.e., timing of delivery), trying to determine the optimal balance between the opposing risks of stillbirth and prematurity. The aim of this study is to determine the likelihood of neonatal complications depending on the time of birth based on Doppler parameters in fetuses with early onset fetal growth restriction; (2) Methods: A case-control study of 205 consecutive pregnant women diagnosed with early onset FGR was conducted at the Obstetrics Clinic of the Municipal Emergency Hospital in Timisoara, Romania; The case group included newborns who were delivered at the onset of umbilical arteries absent/reversed end-diastolic flow, and the control included infants delivered at the onset of reversed/absent ductus venosus A-wave. (3) Results: The overall neonatal mortality rate was 2.0%, and there was no significant statistical difference between the two study groups. In infants delivered up to 30 gestational weeks, grades III/IV intraventricular hemorrhage and bronchopulmonary dysplasia were statistically significantly more frequent in the control group. Moreover, univariate binomial logistic regression analysis on fetuses born under 30 gestational weeks shows that those included in the control group are 30 times more likely to develop bronchopulmonary dysplasia and 14 times more likely to develop intraventricular hemorrhage grades III/IV; (4) Conclusions: Infants delivered according to the occurrence of umbilical arteries absent/reversed end-diastolic flow are less likely to develop intraventricular hemorrhage grades III/IV and bronchopulmonary dysplasia.

Effects of Ponderal Index on Neonatal Mortality and Morbidities in Extremely Premature Infants

BACKGROUND

To evaluate how intrauterine stress affects extremely premature infants in terms of intrauterine growth restriction. We hypothesized that extremely premature infants with mildly-low ponderal index (MPI) would have better neonatal outcomes.

METHODS

We selected 2,721 subjects of 23 to 28 weeks of gestation between 2013 and 2015 from Korean Neonatal Network database. They were divided into 4 groups based on ponderal index (PI) percentile; PI ≤ 3rd as severely-low PI (SPI, n = 82), 3rd < PI ≤ 10th as MPI (n = 190), 10th < PI ≤ 90th as adequate PI (API, n = 2,179), and PI > 90th as high PI (HPI, n = 270).

RESULTS

The mortality in MPI and API groups was comparable (16.3% vs. 16.9%). It was significantly lower than that in the SPI and HPI groups (30.5% and 24.9%, respectively; P = 0.001). The MPI and API groups had better neonatal morbidities compared with the SPI and/or HPI groups, while the MPI group (8.2%) showed a lower incidence of severe intraventricular hemorrhage (IVH) than the other groups (SPI, 21.3%; API, 15.0%; HPI, 19.7%, respectively; P = 0.004). The MPI group had a trend of a bottom in neonatal mortality and morbidities in extremely premature infants.

CONCLUSION

The MPI and API groups had lower mortality, massive pulmonary hemorrhage, severe bronchopulmonary dysplasia or death, pulmonary hypertension and neonatal seizure rates than the SPI and/or HPI groups, while the MPI group showed a lower incidence of severe IVH than the other groups. We speculate that the lower incidence of neonatal morbidities and mortality in the MPI group indicating mild intrauterine stress might accelerate fetal maturation resulting in better outcomes in extremely premature infants.

Present and Future of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common respiratory disorder among infants born extremely preterm. The pathogenesis of BPD involves multiple prenatal and postnatal mechanisms affecting the development of a very immature lung. Their combined effects alter the lung's morphogenesis, disrupt capillary gas exchange in the alveoli, and lead to the pathological and clinical features of BPD. The disorder is ultimately the result of an aberrant repair response to antenatal and postnatal injuries to the developing lungs. Neonatology has made huge advances in dealing with conditions related to prematurity, but efforts to prevent and treat BPD have so far been only partially effective. Seeing that BPD appears to have a role in the early origin of chronic obstructive pulmonary disease, its prevention is pivotal also in long-term respiratory outcome of these patients. There is currently some evidence to support the use of antenatal glucocorticoids, surfactant therapy, protective noninvasive ventilation, targeted saturations, early caffeine treatment, vitamin A, and fluid restriction, but none of the existing strategies have had any significant impact in reducing the burden of BPD. New areas of research are raising novel therapeutic prospects, however. For instance, early topical (intratracheal or nebulized) steroids seem promising: they might help to limit BPD development without the side effects of systemic steroids. Evidence in favor of stem cell therapy has emerged from several preclinical trials, and from a couple of studies in humans. Mesenchymal stromal/stem cells (MSCs) have revealed a reparatory capability, preventing the progression of BPD in animal models. Administering MSC-conditioned media containing extracellular vesicles (EVs) have also demonstrated a preventive action, without the potential risks associated with unwanted engraftment or the adverse effects of administering cells. In this paper, we explore these emerging treatments and take a look at the revolutionary changes in BPD and neonatology on the horizon.

Hydrocortisone and bronchopulmonary dysplasia: variables associated with response in premature infants

OBJECTIVE

The primary objective was to evaluate hydrocortisone's efficacy for decreasing respiratory support in premature infants with developing bronchopulmonary dysplasia (BPD). Secondary objectives included assessment of the impact of intrauterine growth restriction (IUGR), maternal history of chorioamnionitis, side effects and route of administration associated with hydrocortisone's efficacy. Dexamethasone as second-line treatment to decrease respiratory support was reviewed.

METHODS

Retrospective chart review of preterm infants requiring respiratory support receiving hydrocortisone.

RESULTS

A total of 48 patients were included. Successful extubation was achieved in 50% of intubated patients after hydrocortisone treatment with no major complications. In our small study, history of maternal chorioamnionitis, IUGR or route of administration did not affect the response. Rescue dexamethasone after hydrocortisone therapy was ineffective in the ten patients who failed extubation following hydrocortisone.

CONCLUSION

Hydrocortisone is effective in decreasing respiratory support in patients with developing BPD without major complications. Randomized studies are warranted to confirm our findings.

Diagnostic Approach to Pulmonary Hypertension in Premature Neonates

Bronchopulmonary dysplasia (BPD) is a form of chronic lung disease in premature infants following respiratory distress at birth. With increasing survival of extremely low birth weight infants, alveolar simplification is the defining lung characteristic of infants with BPD, and along with pulmonary hypertension, increasingly contributes to both respiratory morbidity and mortality in these infants. Growth restricted infants, infants born to mothers with oligohydramnios or following prolonged preterm rupture of membranes are at particular risk for early onset pulmonary hypertension. Altered vascular and alveolar growth particularly in canalicular and early saccular stages of lung development following mechanical ventilation and oxygen therapy, results in developmental lung arrest leading to BPD with pulmonary hypertension (PH). Early recognition of PH in infants with risk factors is important for optimal management of these infants. Screening tools for early diagnosis of PH are evolving; however, echocardiography is the mainstay for non-invasive diagnosis of PH in infants. Cardiac computed tomography (CT) and magnetic resonance are being used as imaging modalities, however their role in improving outcomes in these patients is uncertain. Follow-up of infants at risk for PH will help not only in early diagnosis, but also in appropriate management of these infants. Aggressive management of lung disease, avoidance of hypoxemic episodes, and optimal nutrition determine the progression of PH, as epigenetic factors may have significant effects, particularly in growth-restricted infants. Infants with diagnosis of PH are managed with pulmonary vasodilators and those resistant to therapy need to be worked up for the presence of cardio-vascular anomalies. The management of infants and toddlers with PH, especially following premature birth is an emerging field. Nonetheless, combination therapies in a multi-disciplinary setting improves outcomes for these infants.

Bronchopulmonary Dysplasia: Chronic Lung Disease of Infancy and Long-Term Pulmonary Outcomes

Bronchopulmonary dysplasia (BPD) is a chronic lung disease most commonly seen in premature infants who required mechanical ventilation and oxygen therapy for acute respiratory distress. While advances in neonatal care have resulted in improved survival rates of premature infants, limited progress has been made in reducing rates of BPD. Lack of progress may in part be attributed to the limited therapeutic options available for prevention and treatment of BPD. Several lung-protective strategies have been shown to reduce risks, including use of non-invasive support, as well as early extubation and volume ventilation when intubation is required. These approaches, along with optimal nutrition and medical therapy, decrease risk of BPD; however, impacts on long-term outcomes are poorly defined. Characterization of late outcomes remain a challenge as rapid advances in medical management result in current adult BPD survivors representing outdated neonatal care. While pulmonary disease improves with growth, long-term follow-up studies raise concerns for persistent pulmonary dysfunction; asthma-like symptoms and exercise intolerance in young adults after BPD. Abnormal ventilatory responses and pulmonary hypertension can further complicate disease. These pulmonary morbidities, combined with environmental and infectious exposures, may result in significant long-term pulmonary sequalae and represent a growing burden on health systems. Additional longitudinal studies are needed to determine outcomes beyond the second decade, and define risk factors and optimal treatment for late sequalae of disease.

Mortality and morbidity risks vary with birth weight standard deviation score in growth restricted extremely preterm infants

OBJECTIVE

To assess whether the mortality and morbidity risks vary with birth weight standard deviation score (BWSDS) in growth restricted extremely preterm infants.

STUDY DESIGN

This was a multicenter retrospective cohort study using the database of the Neonatal Research Network of Japan and including 9149 infants born between 2003 and 2010 at <28 weeks gestation. According to the BWSDSs, the infants were classified as: <-2.0, -2.0 to -1.5, -1.5 to -1.0, -1.0 to -0.5, and ≥-0.5. Infants with BWSDS≥-0.5 were defined as non-growth restricted group.

RESULTS

After adjusting for covariates, the risks of mortality and some morbidities were different among the BWSDS groups. Compared with non-growth restricted group, the adjusted odds ratio (aOR) for mortality [aOR, 1.69; 95% confidence interval (CI), 1.35-2.12] and chronic lung disease (CLD) (aOR, 1.28; 95% CI, 1.07-1.54) were higher among the infants with BWSDS -1.5 to <-1.0. The aOR for severe retinopathy of prematurity (ROP) (aOR, 1.36; 95% CI, 1.09-1.71) and sepsis (aOR, 1.72; 95% CI, 1.32-2.24) were higher among the infants with BWSDS -2.0 to <-1.5. The aOR for necrotizing enterocolitis (NEC) (aOR, 2.41; 95% CI, 1.64-3.55) was increased at a BWSDS<-2.0.

CONCLUSION

Being growth restricted extremely preterm infants confer additional risks for mortality and morbidities such as CLD, ROP, sepsis and NEC, and these risks may vary with BWSDS.

Chorioamnionitis and lung injury in preterm newborns

There is a strong evidence that histologic chorioamnionitis is associated with a reduction of incidence and severity of respiratory distress syndrome (RDS). Short-term maturational effects on the lungs of extremely premature infants seem to be, however, accompanied by a greater susceptibility of the lung, eventually contributing to an increased risk of bronchopulmonary dysplasia (BPD). Genetic susceptibility to BPD is an evolving area of research and several studies have directly related the risk of BPD to genomic variants. There is a substantial heterogeneity across the studies in the magnitude of the association between chorioamnionitis and BPD, and whether or not the association is statistically significant. Considerable variation is largely dependent on differences of inclusion and exclusion criteria, as well as on clinical and histopathological definitions. The presence of significant publication bias may exaggerate the magnitude of the association. Controlling for publication bias may conduct to adjusted results that are no longer significant. Recent studies generally seem to confirm the effect of chorioamnionitis on RDS incidence, while no effect on BPD is seen. Recent data suggest susceptibility for subsequent asthma to be increased on long-term followup. Additional research on this field is needed.

Risk factors for bronchopulmonary dysplasia in five Portuguese neonatal intensive care units

The pathogenesis of bronchopulmonary dysplasia (BPD) is clearly multifactorial. Specific pathogenic risk factors are prematurity, respiratory distress, oxygen supplementation, mechanical ventilation (MV), inflammation, patent ductus arteriosus (PDA), etc.

AIM

To evaluate BPD prevalence and to identify risk factors for BPD in five Portuguese Neonatal Intensive Care Units in order to develop better practices the management of these newborns.

MATERIAL AND METHODS

256 very low birth weight infants with gestational age (GA) <30 weeks and/or birthweight (BW) <1250 g admitted in five Portuguese NICUs, between 2004 and 2006 were studied. A protocol was filled in based on clinical information registered in the hospital charts. BPD was defined as oxygen dependency at 36 weeks of postconceptional age.

RESULTS

BPD prevalence was 12.9% (33/256). BPD risk decreased 46% per GA week and of 39% per 100g BW. BPD risk was significantly higher among newborns with low BW (adj OR= 0.73, 95% CI=0.57- 0.95), severe hyaline membrane disease (adj OR= 9.85, 95% CI=1.05-92.35), and those with sepsis (adj OR=6.22, 95% CI=1.68-23.02), those with longer duration on ventilatory support (42 vs 3 days, respectively in BPD and no BPD patients, p <0.001) and longer duration of FiO2>0.30 (85 vs 5 days, respectively in BPD and no BPD patients, p <0.001).

COMMENTS

The most relevant risk factors were low birth weight, severe hyaline membrane disease, duration of respiratory support and oxygen therapy, and nosocomial sepsis. The implementation of potentially better practices to reduce lung injury in neonates must be addressed to improve practices to decrease these risk factors.

Intrauterine growth restriction and risk for arterial hypertension: a causal relationship?

AIMS

Intrauterine growth restriction (IUGR) has been demonstrated to have serious consequences for health in adult age. These include an increased risk for metabolic syndrome, pulmonary and cardiovascular disorders. These disorders are in part secondary to the development of arterial hypertension, which has been demonstrated to be more frequent in individuals subjected to restricted intrauterine growth.

METHODS

A review on publications on pathogenesis and epidemiology of hypertension associated to IUGR.

RESULTS

Current concepts for this association include a reduced nephrogenesis and increased arterial stiffness, impaired sympathetic regulation and steroid metabolism secondary to IUGR. Early postnatal risk-modifying factors include among others catch-up growth leading to childhood overweight.

CONCLUSION

IUGR increases the risk of hypertension in adult life. Identifying relevant risk factors for arterial hypertension will be the basis for the development of preventive concepts to be applied for predisposed individuals.