Transient tachypnea of the newborn

Left atrial strain assessment unveils left ventricular diastolic dysfunction in neonates with transient tachypnea of the newborn: A prospective observational study

INTRODUCTION

An inadequate clearance of lung fluid plays a key role in the pathogenesis of transient tachypnea of the newborn (TTN).

OBJECTIVES

To evaluate if left ventricular diastolic dysfunction contributes to reduced clearance of lung fluid in TTN.

MATERIALS AND METHODS

This was a prospective, observational study. Echocardiography and lung ultrasound were performed at 2, 24 and 48 h of life (HoL) to assess biventricular function and calculate lung ultrasound score (LUS). Left atrial strain reservoir (LASr) provided surrogate measurement of left ventricular diastolic function.

RESULTS

Twenty-seven neonates with TTN were compared with 27 controls with no difference in gestation (36.1 ± 2 vs. 36.9 ± 2 weeks) or birthweight (2508 ± 667 vs. 2718 ± 590 g). Biventricular systolic function was normal in both groups. LASr was significantly lower in cases at 2 (21.0 ± 2.7 vs. 38.1 ± 4.4; p < 0.01), 24 (25.2 ± 4.5 vs. 40.6 ± 4.0; p < 0.01) and 48 HoL (36.5 ± 5.8 and 41.6 ± 5.2; p < 0.01), resulting in a significant group by time interaction (p < 0.001), after adjusting for LUS and gestational diabetes. A logistic regression model including LUS, birth weight and gestational diabetes as covariates, showed that LASr at 2 HoL was a predictor of respiratory support at 24 HoL, with an adjusted odds ratio of 0.60 (CI 0.36-0.99).

CONCLUSIONS

LASr was reduced in neonates with TTN, suggesting diastolic dysfunction, that may contribute to the delay in lung fluid clearance.

The effect of non-invasive high-frequency oscillatory ventilation on the duration of non-invasive respiratory support in late preterm and term infants with transient tachypnea of the newborn: a randomized controlled trial

Nasal continuous positive airway pressure (nCPAP) is one of the most commonly used non-invasive respiratory support modes in neonates with transient tachypnea of the newborn (TTN). Non-invasive high-frequency oscillatory ventilation (nHFOV) is a non-invasive respiratory support mode that has been increasingly used in neonatal respiratory disorders. This prospective randomized controlled study compared the efficacy of nHFOV and nCPAP in reducing the duration of non-invasive respiratory support. Late preterm and term infants > 34 weeks' gestation were included in the study. The infants were randomly assigned to receive either nHFOV or nCPAP. Treatment was started with standard settings in both groups. Infants who met treatment failure criteria were switched to nasal intermittent mandatory ventilation for further positive-pressure support. A total of 60 infants were included in the study. Thirty of these infants were included in the nHFOV group and 30 were included in the nCPAP group. The median duration of non-invasive respiratory support was not significantly different between the two groups (21 h [IQR: 16-68] for nHFOV vs 15 h [IQR: 11-33] for nCPAP; p = 0.09). However, after adjusting for potential confounders, nHFOV was associated with a shorter duration of non-invasive respiratory support than nCPAP (adjusted mean difference: 16.3 h; 95% CI: 0.7 to 31.9; p = 0.04). nHFOV was well tolerated and did not increase the risk of complications.    Conclusion: Our findings suggest that nHFOV is an effective and safe ventilation mode for late preterm and term neonates with TTN.   Trial registry: Clinicaltrials.gov (NCT03006354). Date of registration: December 30, 2016. What is Known: • nHFOV is a ventilation model that has been increasingly used for the management of RDS. • TTN is one of the most common causes of neonatal respiratory distress. What is New: • nHFOV is associated with shorter duration of non-invasive respiratory support and duration of oxygen support. • nHFOV may be a safe and effective alternative to nCPAP for neonates with TTN.

The diagnostic value of n-terminal probrain natriuretic peptides to differentiate neonatal pneumoniae and transient tachypnea of the newborn

BACKGROUND

The primary objective of the study was to determine the diagnostic value of serum N-terminal probrain natriuretic peptide (NT-proBNP) levels to differentiate neonatal pneumonia (NP) and transient tachypnea of the newborn (TTN). The secondary objective was to investigate the prognostic role of NT-proBNP levels in neonates with severe respiratory distress (RD).

METHODS

A prospective, observational, single-blinded study involving 58 late preterm and term newborns who were diagnosed with TTN or NP was conducted between June 2020 and June 2021 at a level-3 neonatal intensive care unit in Kırıkkale University Faculty of Medicine. TTN and NP groups were compared for serum NT-proBNP levels measured at the 1st and 24th hours of life. Optimal cut-off NT-proBNP value was determined by Youden index to predict the diagnosis of NP. Lung ultrasound was used to support the diagnosis of TTN and NP. In addition, lung ultrasound score (LUS) was used to determine severe RD.

RESULTS

The median of NT-proBNP level was significantly higher at the 24th hour of life in the NP group than in the TTN group, respectively 7263.5 pg/mL (1643-35,000) and 3308 pg/mL (69-19,746), p = 0.004. At a cut-off value of 5515.5 pg/mL, NT-proBNP had a sensitivity of 75% and specificity of 73.8% to predict NP [AUC= 0.749 (95% CI: 0.602-0.895; p = 0.004)]. The study population was divided into two groups as high score group (n: 23, LUS ≥ 7) and low score group (n: 35, LUS < 7) according to the LUS at the 6th hour of life. NT-proBNP values at 24th hour of life were 6320 pg/mL (69-35,000) in high score group and 3500 pg/mL (570-15,948) in low score group, p = 0.044. Duration of oxygen support (p = 0.006), noninvasive ventilation (p = 0.008) and NICU stay (p = 0.004) were higher in high-score group.

DISCUSSION

NT-proBNP values at 24th hour of life can be used as a relatively early predictor in the differentiation between NP and TTN in late preterm and term neonates. In addition, elevated NT-proBNP values are related to the higher LUS which reflects the severity of RD regardless of diagnosis.

Incidence, Clinical Features, and Outcomes of Transient Tachypnea of the Newborn at a Tertiary Care Center in Western India

Background

Transient tachypnea of the newborn (TTN) is a self-limiting, benign condition leading to respiratory distress shortly after birth. It is among the leading cause of respiratory distress in term and late preterm neonates. The disease is transient and resolves by three to four days in most neonates.

Objective

The objective of this study was to study the incidence of TTN, its clinical features, predictors of outcomes and duration of hospital stay in these neonates suffering from it.

Methods

This was a prospective study done at a tertiary care center carried out between August 2019 to July 2021. The study subjects were late pre-term (34 to 36 weeks of gestation) and term neonates with respiratory distress who were admitted to the neonatal intensive care unit (NICU). The diagnosis was based on clinical features, radiological features, and clinical course in NICU.

Results

The total number of cases with TTN was 74. The incidence of TTN was 16 per 1000 live births. 63.5% were male, 75.7% were term births, 70.3% were born via lower section cesarean section (LSCS), and 66.2% were normal birth weight (≥2.5 kg) infants. A high incidence of TTN was found in late pre-term babies, babies born via LSCS, and male sex. None of the neonates required ventilatory support, either noninvasive or invasive.

Conclusion

Delivery by LSCS and male sex were risk factors for the development of TTN. The distress in TTN is usually mild to moderate, and in most cases, oxygen supplementation suffices. Higher Downes’ score at presentation, low birth weight, preterm, and delivery by LSCS were found to be predictors for a longer duration of distress and thus the longer duration of NICU stay. Although severe complications for TTN have been reported in the literature, they are rare. Careful observation can decrease not only a lot of unnecessary investigations but also allow clinicians at secondary and primary centers to better care for neonates with TTN. 

Chest ultrasound in neonates: What neonatologists should know

For many years, ultrasound was thought to have no indications in pulmonary imaging because lungs are filled with air, creating no acoustic mismatch, as encountered by ultrasound wave beam. Lung ultrasound (LUS) was started in adult critical care settings to detect pleural effusion and acquired more indications over time. In the neonatal intensive care unit (NICU), the use of chest ultrasound has gained more attention during the last two decades. Being a radiation-free, bedside, rapid, and handy tool, LUS started to replace chest X-rays in NICU. Using LUS depends upon understanding the nature of normal lungs and the changes induced by different diseases. With the help of LUS, an experienced neonatologist can detect many of the respiratory problems so fast that interventional therapy can be introduced as early as possible. LUS can diagnose pleural effusion, pneumothorax, pneumonia, transient tachypnoea of the newborn, respiratory distress syndrome, pulmonary atelectasis, meconium aspiration syndrome, bronchopulmonary dysplasia, and some other disorders with very high accuracy. LUS will be helpful in initial diagnosis, follow-up, and predicting the need for further procedures such as mechanical ventilation, diuretic therapy, surfactant therapy, etc. There are some limitations to using LUS in some respiratory disorders such as bullae, interstitial emphysema, and other conditions. This review will highlight the importance of LUS, its uses, and limitations.

Protocol for a multicenter, double-blind, randomized, placebo-controlled phase III trial of the inhaled β2-adrenergic receptor agonist salbutamol for transient tachypnea of the newborn (the REFSAL trial)

BACKGROUND

Transient tachypnea of the newborn (TTN), which results from inadequate absorption of fetal lung fluid, is the most common cause of neonatal respiratory distress. Stimulation of β-adrenergic receptors enhances alveolar fluid absorption. Therefore, the β2-adrenergic receptor agonist salbutamol has been proposed as a treatment for TTN. This study aims to evaluate the efficacy and safety of salbutamol as supportive pharmacotherapy together with non-invasive nasal continuous positive airway pressure (NIV/nCPAP) for the prevention of persistent pulmonary hypertension of the newborn (PPHN) in infants with TTN.

METHODS AND ANALYSIS

This multicenter, double-blind, phase III trial will include infants with a gestational age between 32 and 42 weeks who are affected by respiratory disorders and treated in eight neonatal intensive care units in Poland. A total of 608 infants within 24 h after birth will be enrolled and randomly assigned (1:1) to receive nebulized salbutamol with NIV or placebo (nebulized 0.9% NaCl) with NIV. The primary outcome is the percentage of infants with TTN who develop PPHN. The secondary outcomes are the severity of respiratory distress (assessed with the modified TTN Silverman score), frequency of need for intubation, duration of NIV and hospitalization, acid-base balance (blood pH, partial pressure of O₂ and CO₂, and base excess), and blood serum ionogram for Na⁺, K⁺, and Ca²⁺.

DISCUSSION

The Respiratory Failure with Salbutamol (REFSAL) study will be the first clinical trial to evaluate the efficacy and safety of salbutamol in the prevention of persistent pulmonary hypertension in newborns with tachypnea, and will improve short term outcomes. If successful, the study will demonstrate the feasibility of early intervention with NIV/nCPAP together with nebulized salbutamol in the management of TTN.

ETHICS AND DISSEMINATION

The study protocol was approved by the Bioethics Committee of the Medical University of Warsaw, Warsaw, Poland on November 16, 2020 (decision number KB/190/2020). All procedures will follow the principles of the Declaration of Helsinki. The results of the study will be submitted for knowledge translation in peer-reviewed journals and presented at national and international pediatric society conferences.

CLINICAL TRIAL REGISTRATION

It is registered at ClinicalTrials.gov NCT05527704, EudraCT 2020-003913-36; Protocol version 5.0 from 04/01/2022.

Fluid handling and blood flow patterns in neonatal respiratory distress syndrome versus transient tachypnea: a pilot study

Background

Cardiovascular and renal adaptation in neonates with Respiratory Distress Syndrome (RDS) and Transient Tachypnea of the Newborn (TTN) may be different.

Methods

Neonates ≥32 weeks were diagnosed with RDS or TTN based on clinical, radiologic and lung sonographic criteria. Weight loss, feeding, urine output, and sodium levels were recorded for the first 3 days, and serial ultrasounds assessed central and organ Doppler blood flow. A linear mixed model was used to compare the two groups.

Results

Twenty-one neonates were included, 11 with TTN and 10 with RDS. Those with RDS showed less weight loss (− 2.8 +/− 2.7% versus − 5.6 +/− 3.4%), and less enteral feeds (79.2 vs 116 ml/kg/day) than those with TTN, despite similar fluid prescription. We found no difference in urine output, or serum sodium levels. Doppler parameters for any renal or central parameters were similar. However, Anterior Cerebral Artery maximum velocity was lower (p = 0.03), Superior Mesenteric Artery Resistance Index was higher in RDS, compared to TTN (p = 0.02).

Conclusion

In cohort of moderately preterm to term neonates, those with RDS retained more fluid and were fed less on day 3 than those with TTN. While there were no renal or central blood flow differences, there were some cerebral and mesenteric perfusion differences which may account for different pathophysiology and management.

A randomized controlled trial of restricted versus standard fluid management in late preterm and term infants with transient tachypnea of the newborn

BACKGROUND

Transient tachypnea of the newborn(TTNB) is the most common respiratory morbidity in late preterm and term babies and is pathophysiologically related to delayed lung fluid clearance after birth. Mimicking low physiological fluid intake in the initial period of life may accelerate the recovery from TTNB. In a randomized controlled trial, we compared the roles of restricted versus standard fluid management in babies with TTNB requiring respiratory support.

METHODS

This parallel group,non-blinded, stratified randomized controlled trial was conducted in a level III neonatal unit of eastern India. Late preterm and term babies with TTNB requiring continuous positive airway pressure (CPAP) were randomly allocated to standard and restricted fluid arms for the first 72 hours (hrs). Primary outcome was CPAP duration.

RESULTS

In total, 100 babies were enrolled in this study with 50 babies in each arm. CPAP duration was significantly less in the restricted arm (48[42, 54] hrs vs 54[48,72] hrs, p = 0.002). However, no difference was observed in the incidence of CPAP failure between the two arms. In the subgroup analysis, the benefit of reduced CPAP duration persisted in late preterm but not in term infants. However, the effect was not significant in the late preterm babies exposed to antenatal steroid.

CONCLUSION

This trial demonstrated the safety and effectiveness of restrictive fluid strategy in reducing CPAP duration in late preterm and term babies with TTNB. Late preterm babies, especially those not exposed to antenatal steroid were the most benefitted by this strategy.

The neonatal respiratory morbidity associated with early term caesarean section - an emerging pandemic

OBJECTIVES

To examine the impact of early term caesarean section (CS) on respiratory morbidity and early neonatal outcomes when elective caesarean section was carried out before 39 completed weeks gestation in our population.

METHODS

A one-year population-based retrospective cohort analysis using routinely collected hospital data. Livebirths from women who had elective lower segment cesarean section (ELSCS) for uncomplicated singleton pregnancies at early term (ET) 37+0 to 38+6 weeks were compared to full term (FT)≥39+0 weeks gestation. Exclusion criteria included diabetes, antenatal corticosteroid use, stillbirths, immediate neonatal deaths, normal vaginal deliveries and emergency caesareans sections. The outcomes were combined respiratory morbidity (tachypnea [TTN] and respiratory distress syndrome [RDS]), Apgar <7 at 5 min of age, respiratory support, duration of respiratory support and NICU admission.

RESULTS

Out of a total of 1,466 elective CS with term livebirths, the timing of CS was early term (ET) n=758 (52%) and full term (FT) n=708 (48%). There was a higher incidence of respiratory morbidities and neonatal outcomes in the ET in comparison to FT newborns. In the univariable analysis, significant risks for outcomes were: the need for oxygen support OR 2.42 (95% C.I. 1.38-4.22), respiratory distress syndrome and/or transient tachypnea of newborn (RDSF/TTN) OR 2.44 (95% C.I. 1.33-4.47) and neonatal intensive care unit (NICU) admission OR 1.91 (95% C.I. 1.22-2.98). Only the need for oxygen support remained (OR 1.81, 95% C.I. 1.0-3.26) in the multivariable analysis. These results were observed within the context of a significantly higher proportion of older, multiparous, and higher number of previous caesarean sections in the early term CS group.

CONCLUSIONS

There is a significant risk of respiratory morbidities in infants born by elective cesarean section prior to full term gestation. Obstetricians should aim towards reducing the high rate of women with previous multiple cesarean sections including balancing the obstetric indication of early delivery among such women with the evident risk of neonatal respiratory morbidity.

Unfolding the pathophysiology of congenital thrombotic thrombocytopenic purpura in pregnancy: lessons from a cluster of familial cases

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP), a rare, potentially life-threatening thrombotic microangiopathy, manifests either as congenital TTP or acquired forms. It is caused by the absence or severe depletion of a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13) protease, leading to the accumulation of ultra large von Willebrand factor multimers as well as extensive platelet adhesion and clumping, which can ultimately cause severe secondary end-organ damage. Pregnancy can provoke or exacerbate TTP, leading to maternal and fetal complications.

OBJECTIVE

In this report, we focused on pregnancy outcomes in a recently recognized cohort of congenital TTP patients of Bedouin Arab descent in southern Israel who were all homozygous for a novel c.3772delA variant of the ADAMTS13 gene, leading to the clinical manifestations of TTP largely during pregnancy.

STUDY DESIGN

All patients presented in this study belong to 2 closely related families of Arab Bedouin descent and were found to be homozygous for a novel ADAMTS13-c.3772delA variant. The cohort consisted of 19 females; 16 of them had congenital TTP and had been pregnant and were thus included. Patient data were collected from electronic medical records.

RESULTS

Of note, 13 women from our cohort, who delivered 14 fetuses (owing to 1 twin pregnancy), were diagnosed with congenital TTP following complicated pregnancies, which included recurrent pregnancy loss, stillbirth, early onset preeclampsia (both mild and severe), hemolysis, elevated liver enzymes and low platelet count syndrome, intrauterine growth restriction with abnormal Doppler flow, preterm premature rupture of membranes, and a total perinatal mortality rate of 30.7% (4/13). An additional 3 women, who were diagnosed owing to complications outside of pregnancy and at older ages, experienced TTP during their pregnancies, which occurred before diagnosis. Subsequent pregnancies were treated with fresh frozen plasma leading to a 100% fetal survival rate in the pregnancies that reached fetal viability. All placentas had lesions consistent with maternal vascular underperfusion. However, the severity and frequency of these lesions were lower in the 8 placentas from pregnancies treated with fresh frozen plasma.

CONCLUSION

This case series details a distinctive cohort of congenital TTP patients, all homozygous for the same, novel ADAMTS13 variant, who presented with clinical complications during pregnancy and maternal vascular lesions of underperfusion in the placenta. Our findings imply that the variant identified in the ADAMTS13 gene in our cohort may have a specific functional impact on the placenta, and that treatment with fresh frozen plasma during pregnancy ameliorates the course of the disease, leading to a milder phenotype or a normal pregnancy in the majority of cases.

Effect of continuous positive airway pressure versus nasal cannula on late preterm and term infants with transient tachypnea of the newborn

OBJECTIVE

To compare continuous positive airway pressure (CPAP) with nasal cannula (NC) as primary noninvasive respiratory therapy in hypoxic infants for transient tachypnea of the newborn (TTN).

STUDY DESIGN

Retrospective cohort study of infants born at ≥34 weeks of gestation between January 1, 2015 and December 31, 2018.

RESULT

After adjusting for gestational age and birth weight, the maximum fractional inspired oxygen (FiO2) was significantly lower in the CPAP group with an incidence rate ratio (IRR) of 0.85 (95% CI: 0.76-0.96). Although nonsignificant, the CPAP group needed 32% fewer hours on oxygen with an IRR of 0.68 (95% CI: 0.38-1.22). The duration of respiratory support and the incidence of pneumothorax were similar between both groups.

CONCLUSION

Comparing CPAP with NC as initial noninvasive respiratory therapy for TTN, significantly lower maximum FiO2 was observed in the infants of CPAP group without increase in the incidence of pneumothorax.

Antenatal Corticosteroids: Extending the Practice for Late-Preterm and Scheduled Early-Term Deliveries?

Respiratory distress in late-preterm and early term infants generally may warrant admission to a special care nursery or an intensive care unit. In particular, respiratory distress syndrome and transient tachypnea of the newborn are the two most common respiratory morbidities. Antenatal corticosteroids (ACS) facilitate surfactant production and lung fluid resorption. The use of ACS has been proven to be beneficial for preterm infants delivered at less than 34 weeks' gestation. Literature suggests that the benefits of giving antenatal corticosteroids may extend to late-preterm and early term infants as well. This review discusses the short-term benefits of ACS administration in reducing respiratory morbidities, in addition to potential long term adverse effects. An update on the current practices of ACS use in pregnancies greater than 34 weeks' gestation and considerations of possibly extending versus restricting this practice to certain settings will also be provided.

Novel predictor markers for early differentiation between transient tachypnea of newborn and respiratory distress syndrome in neonates

Neonatal Respiratory Distress Syndrome (RDS) and Transient Tachypnea of newborn (TTN) are common similar neonatal respiratory diseases. Study the early predictor markers in differentiation between TTN and RDS in neonates. A prospective case control study which was done in Neonatal Intensive Care Unit (NICU) of Tanta University Hospital (TUH) from September 2016 to March 2018. Three groups of neonates were included in the study: RDS group (45 neonates), TTN group (45 neonates), and control group (45 healthy neonates). There were statistically significant difference (SSD) between our studied three groups as regard serum Malondialdehyde (MDA), Superoxide dismutase SOD, Lactate dehydrogenase (LDH), and blood PH and P-values were 0.001* for these comparative parameters. The ROC curve of RDS cases revealed that the serum MDA Cut off, sensitivity and specificity were 1.87 mmol/L, 98%, 96%, respectively which had the highest sensitivity and specificity followed by the serum SOD then the serum LDH and lastly the blood PH while in TTN cases, the serum MDA Cut off, sensitivity and specificity were 0.74 mmol/L, 96%, 93%, respectively then the serum SOD then the serum LDH and lastly the blood PH. Serum MDA, SOD, LDH, and PH had a beneficial role as early predictors in differentiation between TTN and RDS in neonates.

Salbutamol for transient tachypnea of the newborn

BACKGROUND

Transient tachypnea of the newborn is characterized by tachypnea and signs of respiratory distress. Transient tachypnea typically appears within the first two hours of life in term and late preterm newborns. Although transient tachypnea of the newborn is usually a self-limited condition, it is associated with wheezing syndromes in late childhood. The rationale for the use of salbutamol (albuterol) for transient tachypnea of the newborn is based on studies showing that β-agonists can accelerate the rate of alveolar fluid clearance. This review was originally published in 2016 and updated in 2020.

OBJECTIVES

To assess whether salbutamol compared to placebo, no treatment or any other drugs administered to treat transient tachypnea of the newborn, is effective and safe for infants born at 34 weeks' gestational age with this diagnosis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2020, Issue 4) in the Cochrane Library; PubMed (1996 to April 2020), Embase (1980 to April 2020); and CINAHL (1982 to April 2020). We applied no language restrictions. We searched the abstracts of the major congresses in the field (Perinatal Society of Australia New Zealand and Pediatric Academic Societies) from 2000 to 2020 and clinical trial registries.

SELECTION CRITERIA

Randomized controlled trials, quasi-randomized controlled trials and cluster trials comparing salbutamol versus placebo or no treatment or any other drugs administered to infants born at 34 weeks' gestational age or more and less than three days of age with transient tachypnea of the newborn.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology for data collection and analysis. The primary outcomes considered in this review were duration of oxygen therapy, need for continuous positive airway pressure and need for mechanical ventilation. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Seven trials, which included 498 infants, met the inclusion criteria. All trials compared a nebulized dose of salbutamol with normal saline. Four studies used one single dose of salbutamol; in two studies, three to four doses were provided; in one study, additional doses were administered if needed. The certainty of the evidence was low for duration of hospital stay and very low for the other outcomes. Among the primary outcomes of this review, four trials (338 infants) reported the duration of oxygen therapy, (mean difference (MD) -19.24 hours, 95% confidence interval (CI) -23.76 to -14.72); one trial (46 infants) reported the need for continuous positive airway pressure (risk ratio (RR) 0.73, 95% CI 0.38 to 1.39; risk difference (RD) -0.15, 95% CI -0.45 to 0.16), and three trials (254 infants) reported the need for mechanical ventilation (RR 0.60, 95% CI 0.13 to 2.86; RD -0.01, 95% CI -0.05 to 0.03). Both duration of hospital stay (4 trials; 338 infants) and duration of respiratory support (2 trials, 228 infants) were shorter in the salbutamol group (MD -1.48, 95% CI -1.8 to -1.16; MD -9.24, 95% CI -14.24 to -4.23, respectively). One trial (80 infants) reported duration of mechanical ventilation and pneumothorax but data could not be extracted due to the reporting of these outcomes (type of units of effect measure and unclear number of events, respectively). Five trials are ongoing.

AUTHORS' CONCLUSIONS

There was limited evidence to establish the benefits and harms of salbutamol in the management of transient tachypnea of the newborn. We are uncertain whether salbutamol administration reduces the duration of oxygen therapy, duration of tachypnea, need for continuous positive airway pressure and for mechanical ventilation. Salbutamol may slightly reduce hospital stay. Five trials are ongoing. Given the limited and low certainty of the evidence available, we could not determine whether salbutamol was safe or effective for the treatment of transient tachypnea of the newborn.

Can immature platelet fraction be an early predictor for congenital pneumonia?

Aim:

Timely diagnosis and treatment of congenital pneumonia are crucial. A new hematologic parameter, immature platelet fraction, has been used to gather clinical information on the prognosis of thrombocytopenia, as well as to measure inflammatory activity in adult patients. This study aimed to compare immature platelet fraction and sepsis biomarkers in late-preterm infants diagnosed as having congenital pneumonia and to evaluate its predictive value for congenital pneumonia.

Material and Methods:

Late-preterms were categorized based on infectious vs. non-infectious etiology of respiratory distress. Two sets of blood samples for markers were taken at 12–24 (sample-1) and 48–72 hours (sample-2) after birth. Immature platelet fraction was measured using a Sysmex XN-3000 analyzer.

Results:

From a total of 30 non-thrombocytopenic late-preterms, 16 were included in the congenital pneumonia group and 14 comprised the transient tachypnea group. The groups were comparable in terms of gestational age, birth weight, and cesarean section rate. The proportion of prolonged membrane rupture was significantly higher in the congenital pneumonia group. Values of immature platelet fraction-1, immature platelet fraction-2, and procalcitonin-2 were significantly higher in the congenital pneumonia group than in the transient tachypnea group. No significant differences were found between the groups in other biomarkers. It was determined that an immature platelet fraction-1 cut-off value of 2.9% could predict congenital pneumonia with a sensitivity of 65%, a specificity of 71.4%, a positive predictive value of 70.5%, and negative predictive value of 63.7% (area under the curve=0.724; p=0.028).

Conclusion:

Immature platelet fraction may have an early predictive role in the diagnosis of congenital pneumonia.

Term Newborns with relatively low Tissue Oxygen Saturation Levels soon after Birth are predisposed to Neonatal Respiratory Disorders in Low-risk, Elective Cesarean Sections

Background: Neonatal respiratory disorders, such as transient tachypnea of the newborn and respiratory distress syndrome, occur frequently after an elective cesarean delivery. Although conventional pulse oximetry is recommended for neonatal resuscitation, it often requires several minutes after birth to obtain a reliable signal. In a previous study, we used novel tissue oximetry equipment to detect fetal and neonatal early tissue oxygen saturation (StO₂) before and immediately after vaginal delivery. Therefore, we hypothesized that low neonatal StO₂ levels measured by tissue oximetry may lead to neonatal respiratory disorder after a scheduled cesarean delivery. Hence, this study aimed to evaluate the StO₂ levels measured by tissue oximetry in neonates with or without a respiratory disorder subsequently diagnosed after an elective cesarean delivery. Materials and methods: We enrolled 78 pregnant Japanese women who underwent an elective cesarean section at ≥36 weeks' gestation. After combined spinal and epidural anesthesia were administered to the mother, fetal StO₂ levels were measured by tissue oximetry using an examiner's finger-mounted sensor during a pelvic examination immediately before the cesarean section. We measured the neonatal StO₂ levels at 1, 3, and 5 minutes after birth and retrospectively compared the fetal and neonatal StO₂ levels with the incidence of subsequent diagnoses of neonatal respiratory disorders. Results: The data of StO₂ levels in 35 neonates were collected. Seven neonates (respiratory disorder (RD) group) were subsequently diagnosed with respiratory disorders by neonatal medicine specialists, whereas the 28 remaining neonates (NR group) were not. The median fetal StO₂ (interquartile range) of the RD and NR groups was 52.0% (41.8%-60.8%) and 42.5% (39.0%-52.5%), respectively (P = 0.12). The median neonatal StO₂ (interquartile range) of the RD and NR groups at 1 minute after birth was 42.0% (39.0%-44.0%) and 46.0% (42.0%-49.0%), respectively (P = 0.091). At 3 minutes after birth, the median neonatal StO₂ (interquartile range) of the RD and NR groups was 41.0% (39.0%-46.0%) and 47.0% (44.3%-53.5%), respectively (P = 0.004). Finally, at 5 minutes after birth, the median neonatal StO₂ (interquartile range) of the RD and NR groups was 45.0% (44.0%-52.0%) and 54.0% (49.3%-57.0%), respectively (P = 0.007). Conclusions: The StO₂ values in the RD group were lower than those in the NR group at 3 and 5 minutes after birth, suggesting that neonates with low StO₂ levels soon after birth may be predisposed to clinically diagnosed neonatal respiratory disorders.

Recent Advances in Pathophysiology and Management of Transient Tachypnea of Newborn

Transient tachypnea of newborn (TTN) results from failure of the newborn to effectively clear the fetal lung fluid soon after birth. TTN represents the most common etiology of respiratory distress in term gestation newborns and sometimes requires admission to the neonatal intensive care unit. TTN can lead to maternal-infant separation, the need for respiratory support, extended unnecessary exposure to antibiotics and prolonged hospital stays. Recent evidence also suggests that TTN may be associated with wheezing syndromes later in childhood. New imaging modalities such as lung ultrasound can help in the diagnosis of TTN and early management with distending pressure using continuous positive airway pressure may prevent exacerbation of respiratory distress.

Procalcitonin Level at 24 Hours of Age May be Predictive for Transient Tachypnea of the Newborn

Objective It is an important problem to differentiate transient tachypnea of the newborn (TTN) from bacterial pneumonia or other conditions in patients admitted to Neonatal Intensive Care Unit. The aim of this study was to evaluate the predictive value of procalcitonin (PCT) for TTN.

Methods A total of 52 infants were contained in the study. The patients were divided into three groups. Group 1 consisted of patients with pronounced grunting at more than 2 hours postnatal age (n = 16). Group 2 consisted of patients whose grunt was reduced or gone at 2 hours postnatal age but in whom tachypnea persisted until 24 hours postnatal age (n = 18). Group 3 consisted of patients with minimal or no respiratory distress at 24 hours postnatal age (n = 18). In all groups, PCT concentrations were determined at birth and 24 hours postnatal age.

Results PCT concentrations at birth were significantly higher in Group 1 than other groups, but there was no difference between Groups 2 and 3. PCT concentrations at 24 hours postnatal age were significantly higher in Groups 1 and 2 than Group 3. No difference was found between Group 1 and Group 2 at 24 hours postnatal age. All PCT concentrations in Group 3 were significantly lower than other groups. PCT thresholds for the diagnosis of TTN were 0.44 ng/mL at birth (sensitivity 58%, specificity 50%) and 5.11 ng/mL at 24 hours postnatal age (sensitivity 79.4%, specificity 89.1%).

Conclusion Serial PCT measurements at birth and postnatal 24 hours may be helpful in differentiating between pneumonia and TTN. Further researches are needed to confirm this initial study.

Non-invasive forced oscillometry to quantify respiratory mechanics in term neonates

BACKGROUND

To determine normative data by forced oscillation technique (FOT) in non-sedated normal term neonates and test the hypothesis that infants with transient tachypnea of the newborn (TTN) have higher resistance (R) and lower reactance (X) on day 1.

METHODS

Healthy term infants (n = 138) and infants with TTN (n = 17) were evaluated on postnatal days 1 through 3 (NCT03346343). FOT was measured with a mask using a TremoFlo C-100 Airwave System™. R, X, and area under the reactance curve (AX) were measured at prime frequencies 7-41 Hz for 8 s.

RESULTS

In all, 86% of control infants had adequate measurements (coherence >0.8, CV < 0.25) on day 1. Infants with TTN had higher resistance at 13 Hz (TTN 32.5 cm H₂O·s/L [95% CI 25.5-39.4]; controls 23.8 cm H₂O·s/L [95% CI 22.2 to 25.3], P = 0.007) and lower reactance from 17 to 37 Hz (TTN -35.1 to -10.5; controls -26.3 to -6.1, P < 0.05). In healthy controls, lung mechanics were unchanged from days 1 to 3. In TTN, lung mechanics normalized on days 2 and 3.

CONCLUSIONS

FOT is feasible in neonates and distinguishes normal control infants from those with TTN on postnatal day 1. Oscillometry offers a non-invasive, longitudinal technique to assess lung mechanics in newborns.

Randomized trial of mask or prongs for nasal intermittent mandatory ventilation in term infants with transient tachypnea of the newborn

BACKGROUND

The aim of this study was to compare nasal masks (NM) with binasal prongs (NP) for applying nasal intermittent mandatory ventilation (NIMV) by assessing the duration of respiratory distress, rate of intubation, and nasal trauma in term infants with transient tachypnea of the newborn (TTN).

METHODS

Infants with a gestational age ≥37 weeks and birthweight ≥2,000 g who had NIMV administered for TTN were enrolled. We randomly allocated 80 neonates to the NM (n = 40) or NP (n = 40) group. Duration of respiratory distress was the primary outcome of this study.

RESULTS

There were no statistically significant differences between the groups for the duration of tachypnea and NIMV (P = 0.94 and P = 0.13, respectively). No significant differences were observed between the two groups in terms of duration of oxygen supplementation and length of hospitalization (P = 0.72 and P = 0.70, respectively). The incidence of any grade of trauma and moderate trauma (grade II) was significantly higher in the NP group than in the NM group (P = 0.004 and P = 0.04, respectively). The rate of NIMV failure and other complications, including pneumothorax, pneumonia and feeding intolerance, was not significantly different in the groups.

CONCLUSIONS

In term infants with TTN, delivering NIMV using NP in comparison to using NM appears to be similar with regard to the duration of respiratory distress and preventing intubation. However, the use of NP involves a greater risk of trauma than that of NM.

Postnatal corticosteroids for transient tachypnoea of the newborn

BACKGROUND

Transient tachypnoea of the newborn (TTN) is characterized by tachypnoea and signs of respiratory distress. Transient tachypnoea typically appears within the first two hours of life in term and late preterm newborns. The administration of corticosteroids might compensate for the impaired hormonal changes which occur when infants are delivered late preterm, or at term but before the onset of spontaneous labour (elective caesarean section). Corticosteroids might improve the clearance of liquid from the lungs, thus reducing the effort required to breathe and improving respiratory distress.

OBJECTIVES

The objective of this review is to assess whether postnatal corticosteroids - compared to placebo, no treatment or any other drugs administered to treat TTN - are effective and safe in the treatment of TTN in infants born at 34 weeks' gestational age or more.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 2), MEDLINE (1996 to 19 February 2019), Embase (1980 to 19 February 2019) and CINAHL (1982 to 19 February 2019). We applied no language restrictions. We searched clinical trial registries for ongoing studies.

SELECTION CRITERIA

We included randomized controlled trials, quasi-randomized controlled trials and cluster-randomized trials comparing postnatal corticosteroids versus placebo or no treatment or any other drugs administered to infants born at 34 weeks' gestational age or more and less than three days of age with TTN.

DATA COLLECTION AND ANALYSIS

For each of the included trials, two review authors independently extracted data (e.g. number of participants, birth weight, gestational age, duration of oxygen therapy, need for continuous positive airway pressure, need for mechanical ventilation, duration of mechanical ventilation, etc.) and assessed the risk of bias (e.g. adequacy of randomization and blinding, completeness of follow-up). The primary outcomes considered in this review were need for nasal continuous positive airway pressure and need for mechanical ventilation. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

One trial, which included 49 infants, met the inclusion criteria. The trial compared the use of inhaled corticosteroids (budesonide) with placebo. We found no differences between groups in terms of need for nasal continuous positive airway pressure (risk ratio (RR) 1.27, 95% confidence interval (CI) 0.65 to 2.51; 1 study, 49 participants) and need for mechanical ventilation (RR 0.52, 95% CI 0.05 to 5.38; 1 study, 49 participants). The type of mechanical ventilation used in the included study was high-frequency oscillation. Tests for heterogeneity were not applicable for any of the analyses as only one study was included. Out of the secondary outcomes we deemed to be of greatest importance to patients, the study only reported on duration of hospital stay, which was no different between groups. The quality of the evidence is very low, due to the imprecision of the estimates and indirectness. We identified no ongoing trials.

AUTHORS' CONCLUSIONS

Given the paucity and very low quality of the available evidence, we are unable to determine the benefits and harms of postnatal administration of either inhaled or systemic corticosteroids for the management of TTN.

Transient Tachypnea of Newborns Is Associated With Maternal Spinal Hypotension During Elective Cesarean Delivery: A Retrospective Cohort Study

BACKGROUND

The risk for transient tachypnea of newborns, a common cause of respiratory distress in the neonatal period, is 2- to 6-fold higher during elective cesarean delivery compared to vaginal delivery. Here, we evaluated the association between transient tachypnea of newborns and the degree and duration of predelivery maternal hypotension during spinal anesthesia for elective cesarean delivery.

METHODS

Demographic data, details of anesthetic management, blood pressure measurements, and vasopressor requirement preceding delivery were compared between transient tachypnea newborns (n = 30) and healthy neonates (n = 151) with normal respiratory function born via elective cesarean delivery between July 2015 and February 2016. The degree and duration of hypotension were assessed using area under the curve for systolic blood pressure (SBP) ≤90 mm Hg and area under the curve for mean arterial pressure ≤65 mm Hg. After adjusting for confounders, multivariable logistic regression was used to evaluate the association between area under the curve for SBP and transient tachypnea of newborns.

RESULTS

The median area under the curve for SBP was higher in cases of transient tachypnea of newborns (0.94; interquartile range, 0-28.7 mm Hg*min) compared to healthy controls (0; interquartile range, 0-3.30 mm Hg*min; P = .001). Similarly, median area under the curve for mean arterial pressure was also higher in cases of transient tachypnea of newborns (0; interquartile range, 0-18.6 mm Hg*min) compared to controls (0; interquartile range, 0-1.1 mm Hg*min; P = .01). Mothers of transient tachypnea newborns received significantly higher amounts of phenylephrine and ephedrine compared to controls (P = .001 and 0.01, respectively). Hence, the total vasopressor dose given to mothers in the transient tachypnea of newborn group was much higher than for the control group (P = .001). In the multivariable logistic regression, area under the curve for SBP was significantly associated with transient tachypnea of newborns (odds ratio, 1.02; 95% CI, 1.01-1.04, P = .005) after adjusting for gravidity and the type of anesthetic (spinal versus combined spinal epidural).

CONCLUSIONS

Our results suggest that the degree and duration of maternal SBP <90 mm Hg after neuraxial anesthesia during elective cesarean delivery are associated with transient tachypnea of newborns. Future prospective studies should further explore the effects of maternal hypotension, its prevention, and treatment for transient tachypnea of newborns.

Interventions for the Management of Respiratory Distress in Late Preterm and Term Infants Experiencing Delayed Respiratory Transition: A Systematic Review

OBJECTIVES

To examine the best available evidence for interventions used to manage mild to moderate respiratory distress in late preterm and term infants experiencing delayed respiratory transition.

DATA SOURCES

EMBASE, MEDLINE, Cochrane Review, Joanna Briggs, PubMed, CINAHL, and Google Scholar online databases were searched for articles related to delayed respiratory transition. Reference lists were reviewed to identify additional articles for inclusion.

STUDY SELECTIONS

Randomized, blinded, placebo-controlled, randomized prospective, prospective observational, and retrospective cohort studies published in English-language, peer-reviewed journals between 2007 and August 2017 were reviewed for inclusion. Studies were included if they examined respiratory focused interventions that could potentially prevent admission to the neonatal intensive care unit (NICU) of the term or late preterm infant transitioning to extrauterine life.

DATA EXTRACTION

The CASP tools were utilized for appraisal of individual studies. Data were extracted from the 5 studies included in this review.

DATA SYNTHESIS

In 4 of the 5 studies, prevention of NICU admission was the primary aim. The observational study observed videos of newborn resuscitations and described the effect of early intervention with continuous positive-airway pressure (CPAP) ventilation on prevention of NICU admission for respiratory distress. One randomized controlled trial used adrenaline injections to prevent development of respiratory distress. The 3 remaining randomized controlled trials used prophylactic CPAP or sustained inflation as a method for preventing development of delayed respiratory transition. Three of the 5 studies focused exclusively on cesarean born infants. Among the interventions studied, early or prophylactic CPAP shows the most promise for prevention of NICU admission in late preterm and term infants with mild to moderate respiratory distress.

CONCLUSION

The lack of safety and efficacy data for either adrenaline injections or prophylactic CPAP precludes either method for current use in the prevention of respiratory distress for the late preterm or term infant transitioning to extrauterine life. Two randomized trials, both using prophylactic CPAP, had a significant decrease in NICU admissions. Both studies were conducted at a single center and exclusive to infants born by cesarean delivery. A single study using sustained lung inflation showed no significant difference in the need for respiratory support or NICU admission. A single study using adrenaline also showed no benefit to the prevention of respiratory distress related to transition. Further multicenter randomized controlled trials are needed before broad adoption of early or prophylactic CPAP can be recommended.

A Comparative Trial of the Effectiveness of Nasal Interfaces Used to Deliver Continuous Positive Airway Pressure for a Brief Period in Infants With Transient Tachypnea of the Newborn

INTRODUCTION

There is insufficient data on the effectiveness of the interfaces used for nasal continuous airway pressure (nCPAP) in newborn infants. Transpulmonary pressure (PTP) calculated from a measured esophageal pressure (Pes) could be used as a surrogate for the pressure transmitted to the distal airways during nCPAP. We aimed to compare the effectiveness of two nasal interfaces, the nasal mask and bi-nasal short prongs, during a relatively brief period of respiratory support by calculated PTP (cPTP) in infants with transient tachypnea of the newborn (TTN).

METHODS

Newborns with TTN who needed respiratory assistance with nCPAP were randomized to use either bi-nasal short prongs or a nasal mask. Esophageal pressure measurements were done in order to calculate PTP with either interface. The primary outcome was the cPTP transmitted with each nasal interface. Esophageal pressure measurements were recorded and PTP values were calculated from Pes measurements at the 1st, 6th, 12th and 24th hours in each patient as long as the respiratory support lasted.

RESULTS

Sixty-two newborns with TTN and on nCPAP were randomized into two groups: Group 1 to use bi-nasal short prongs (n: 31) and Group 2 to use a nasal mask (n: 31). Inspiratory and expiratory Pes and cPTP values at the 1st, 6th, 12th and 24th hours were similar with the two interfaces (P<.05).

CONCLUSIONS

A nasal mask is similarly effective and safe as bi-nasal short prongs during a brief period of non-invasive respiratory support with nCPAP in late preterm and term neonates with TTN.

Platelet mass index and prediction of severity of transient tachypnea of the newborn

BACKGROUND

Platelet mass index (PMI) is associated with platelet functionality. The aim of this study was to evaluate the role of PMI in predicting the severity of transient tachypnea of the newborn (TTN).

METHODS

Infants with gestational age ≥37 weeks and birthweight ≥2,000 g who were given nasal intermittent mandatory ventilation for TTN ≤6 h after birth were retrospectively enrolled in this study. PMI was calculated using the following formula: PMI = platelet count × mean platelet volume/10³ (fL/nL). The study infants (n = 101) were divided into two groups according to the duration of tachypnea: ≤48 h (n = 45) and >48 h (n = 56).

RESULTS

The PMI and platelet count were significantly lower in the group with tachypnea duration >48 h than in the tachypnea duration ≤48 h group (P < 0.001 and P = 0.04, respectively). A negative significant correlation was noted between PMI and the duration of tachypnea (r = -0.43, P < 0.001). A PMI cut-off of 1,562 fL/nL can predict prolonged tachypnea (>48 h) with a sensitivity of 62.5%, specificity of 68.9%, positive predictive value of 71.4%, and negative predictive value of 59.6% (area under the curve, 0.682 ± 0.053; P = 0.002).

CONCLUSIONS

Lower PMI and lower platelet count are associated with longer duration of tachypnea in patients with TTN.

The Perinatal Asphyxiated Lamb Model: A Model for Newborn Resuscitation

Birth asphyxia accounts for nearly one million deaths worldwide each year, and is one of the primary causes of early neonatal morbidity and mortality. Many aspects of the current neonatal resuscitation guidelines remain controversial given the difficulties in conducting randomized clinical trials owing to the infrequent and often unpredictable need for extensive resuscitation. Most studies on neonatal resuscitation stem from manikin models that fail to truly reflect physiologic changes or piglet models that have cleared their lung fluid and that have completed the transition from fetal to neonatal circulation. The present protocol provides a detailed step-by-step description on how to create a perinatal asphyxiated fetal lamb model. The proposed model has a transitioning circulation and fluid-filled lungs, which mimics human newborns following delivery, and is, therefore, an excellent animal model to study newborn physiology. An important limitation to lamb experiments is the higher associated cost.

Ultrasound in neonatal lung disease

Lung diseases in neonates can be life-threatening condition and may result in respiratory failure and death. Chest X-ray is a traditional diagnostic technique that results in radiation exposure to patients. Lung ultrasound is a user-friendly imaging technique that has been increasingly used in clinical practice in recent years and presents the advantages of real-time imaging and without radiation. Here we review the sonographic appearances of common neonatal lung diseases and present demonstration of typical cases.

A non-invasive method to rule out transient tachypnea of the newborn (TTN): fetal pulmonary artery acceleration to ejection time ratio

OBJECTIVE

To investigate whether fetal pulmonary artery acceleration to ejection time (PATET) ratio can predict or rule out subsequent diagnosis of transient tachypnea of the newborn (TTN).

METHODS

This prospective cohort study included 105 pregnant women in labor, who met the inclusion criteria. Eighteen of these women were removed from the study cohort, because of an inability to acquire sufficient Doppler waveforms and a longer duration of deliveries. According to subsequent diagnosis of TTN in the neonate, the two groups were constituted, TTN+ and TTN-.

RESULTS

There were no statistically significant differences between the groups regarding maternal obstetric and demographic features. The neonatal intensive care unit (NICU) submission rate was significantly higher in the TTN+ group (100%, 17%, P<0.0001, respectively). Regarding the fetal pulmonary artery Doppler findings, PATET ratio in the TTN+ group was significantly lower than the TTN- group (0.307 vs. 0.389, P<0.0001, respectively). The PATET ratio and diagnosis of TTN were inversely correlated (r=-0.41, P<0.001), even if adjusted for birth weight, gestational age and fetal gender (r=0.42, P=0.0021). The cut-off value of 0.319 provided 82.7% specificity, 83.3% sensitivity, 96% negative predictive value and 41.6% positive predictive value. Additionally intraobserver ICC for PATET was found to be 0.86.

CONCLUSION

The fetal PATET ratio seems to serve as a promising tool to rule out subsequent diagnosis of TTN.

Regional Variation in Neonatal Intensive Care Admissions and the Relationship to Bed Supply

OBJECTIVE

To characterize geographic variation in neonatal intensive care unit (NICU) admission rates across the entire birth cohort and evaluate the relationship between regional bed supply and NICU admission rates.

STUDY DESIGN

This was a population-based, cross-sectional study. 2013 US birth certificate and 2012 American Hospital Association data were used to assign newborns and NICU beds to neonatal intensive care regions. Descriptive statistics of admission rates were calculated across neonatal intensive care regions. Multilevel logistic regression was used to examine the relationship between bed supply and individual odds of admission, with adjustment for maternal and newborn characteristics.

RESULTS

Among 3 304 364 study newborns, the NICU admission rate was 7.2 per 100 births and varied across regions for all birth weight categories. IQRs in admission rates were 84.5-93.2 per 100 births for 500-1499 g, 35.3-46.1 for 1500-2499 g, and 3.5-5.5 for ≥2500 g. Adjusted odds of admission for newborns of very low birth weight were unrelated to regional bed supply; however, newborns ≥2500 g in regions with the highest NICU bed supply were significantly more likely to be admitted to a NICU than those in regions with the lowest (aOR 1.20 [1.03-1.40]).

CONCLUSIONS

There is persistent underuse of NICU care for newborns of very low birth weight that is not associated with regional bed supply. Among larger newborns, we find evidence of supply-sensitive care, raising concerns about the potential overuse of expensive and unnecessary care. Rather than improving access to needed care, NICU expansion may instead further deregionalize neonatal care, exacerbating underuse.

Factors relating caesarean section to persistent pulmonary hypertension of the newborn

BACKGROUND

Several studies have clearly demonstrated a significantly higher incidence of persistent pulmonary hypertension of the newborn (PPHN) in neonates delivered by caesarean section (CS) compared to those delivered vaginally. The pathophysiological factors underlying the link between CS and PPHN are still poorly understood. In this review, we describe the mechanisms that could explain the association between CS delivery and subsequent PPHN, as well as potential preventive measures.

DATA SOURCES

A literature search was conducted by electronic scanning of databases such as PubMed and Web of Science using the key words "persistent pulmonary hypertension of the newborn", "caesarean section", "iatrogenic prematurity", "oxidative stress", "late preterm", "labor" and "vasoactive agents".

RESULTS

Iatrogenic prematurity, higher rates of late preterm delivery and lack of physiological changes of labor play an important role in the association between CS and PPHN. CS delivery also results in limited endogenous pulmonary vasodilator synthesis and lower levels of protective anti-oxidants in the neonates. In addition, CS delivery exposes infants to a higher risk of respiratory distress syndrome and its concomitant increase in endothelin-1 levels, which might indirectly lead to a higher risk of developing PPHN. We believe that neonates delivered by CS are exposed to a combination of these pathophysiological events, culminating in an endpoint of respiratory distress, hypoxia, acidosis, and delayed transition and thereby increased risks of PPHN. The use of antenatal corticosteroids prior to elective CS in late preterm deliveries, promoting accurate informedconsent process, delaying elective CS to 39 weeks of gestation or beyond and antenatal maternal anti-oxidant supplementation could potentially mitigate the effects of CS delivery and minimize CS-related PPHN.

CONCLUSIONS

The link between CS delivery and PPHN is complex. In view of the rising rates of CS worldwide, there is an urgent need to further explore the mechanisms linking CS to PPHN and experimentally test therapeutic options in order to allow effective targeted interventions.

Increased asymmetric dimethylarginine levels in severe transient tachypnea of the newborn

OBJECTIVE

Nitric oxide (NO) is synthesized by NO synthase (NOS), and asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NOS. We aimed to investigate l-arginine and ADMA levels in transient tachypnea of the newborn (TTN) and their relationship with systolic pulmonary artery pressure (PAP) and disease severity.

STUDY DESIGN

Infants born at ⩾35 weeks gestational age with clinical signs and chest X-ray findings consistent with TTN were enrolled; controls were recruited at the same time. l-arginine and ADMA levels were measured at 12 to 24 h (first samples) and at 48 to 72 h (second samples). Systolic PAP was evaluated on the second day. Patients were divided according to the duration of tachypnea and designated as group A (duration ⩽72 h) and group B (duration >72 h).

RESULTS

In the first samples, the ADMA levels were significantly higher in patients with TTN compared with controls (P<0.001). In the second samples, the ADMA levels were significantly higher in group B compared with that in group A (P=0.019). In group A patients, the second ADMA levels were significantly lower compared with that in the first samples (P<0.001), whereas the second ADMA levels remained unchanged compared with the first samples in group B. Systolic PAP values were significantly higher in group B compared with that in group A patients (P=0.033).

CONCLUSION

Increased ADMA concentration may reduce NO synthesis, leading to increased PAP and thus longer duration of tachypnea.

Epinephrine for transient tachypnea of the newborn

BACKGROUND

Transient tachypnea of the newborn is characterized by tachypnea and signs of respiratory distress. Transient tachypnea typically appears within the first two hours of life in term and late preterm newborns. Although transient tachypnea of the newborn is usually a self limited condition, it is associated with wheezing syndromes in late childhood. The rationale for the use of epinephrine (adrenaline) for transient tachypnea of the newborn is based on studies showing that β-agonists can accelerate the rate of alveolar fluid clearance.

OBJECTIVES

To assess whether epinephrine compared to placebo, no treatment or any other drugs (excluding salbutamol) is effective and safe in the treatment of transient tachypnea of the newborn in infants born at 34 weeks' gestational age or more.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 3), MEDLINE (1996 to March 2016), EMBASE (1980 to March 2016) and CINAHL (1982 to March 2016). We applied no language restrictions. We searched the abstracts of the major congresses in the field (Perinatal Society of Australia and New Zealand and Pediatric Academic Societies) from 2000 to 2015.

SELECTION CRITERIA

Randomized controlled trials, quasi-randomized controlled trials and cluster trials comparing epinephrine versus placebo or no treatment or any other drugs administered to infants born at 34 weeks' gestational age or more and less than three days of age with transient tachypnea of the newborn.

DATA COLLECTION AND ANALYSIS

For the included trial, two review authors independently extracted data (e.g. number of participants, birth weight, gestational age, duration of oxygen therapy (hours), need for continuous positive airway pressure and need for mechanical ventilation, duration of mechanical ventilation, etc.) and assessed the risk of bias (e.g. adequacy of randomization, blinding, completeness of follow-up). The primary outcomes considered in this review were duration of oxygen therapy (hours), need for continuous positive airway pressure and need for mechanical ventilation.

MAIN RESULTS

One trial, which included 20 infants, met the inclusion criteria of this review. Study authors administered three doses of nebulized 2.25% racemic epinephrine or placebo. We found no differences between the two group in the duration of supplemental oxygen therapy (mean difference (MD) -6.60, 95% confidence interval (CI) -54.80 to 41.60 hours) and need for mechanical ventilation (risk ratio (RR) 0.67, 95% CI 0.08 to 5.88; risk difference (RD) -0.07, 95% CI -0.46 to 0.32). Among secondary outcomes, we found no differences in terms of initiation of oral feeding. The quality of the evidence was limited due to the imprecision of the estimates.

AUTHORS' CONCLUSIONS

At present there is insufficient evidence to determine the efficacy and safety of epinephrine in the management of transient tachypnea of the newborn.

Salbutamol for transient tachypnea of the newborn

BACKGROUND

Transient tachypnea of the newborn is characterized by tachypnea and signs of respiratory distress. Transient tachypnea typically appears within the first two hours of life in term and late preterm newborns. Although transient tachypnea of the newborn is usually a self limited condition, it is associated with wheezing syndromes in late childhood. The rationale for the use of salbutamol (albuterol) for transient tachypnea of the newborn is based on studies showing that β-agonists can accelerate the rate of alveolar fluid clearance.

OBJECTIVES

To assess whether salbutamol compared to placebo, no treatment or any other drugs administered to treat transient tachypnea of the newborn, is effective and safe in the treatment of transient tachypnea of the newborn in infants born at 34 weeks' gestational age or more.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 3), MEDLINE (1996 to March 2016), EMBASE (1980 to March 2016) and CINAHL (1982 to March 2016). We applied no language restrictions. We searched the abstracts of the major congresses in the field (Perinatal Society of Australia New Zealand and Pediatric Academic Societies) from 2000 to 2015 and clinical trial registries.

SELECTION CRITERIA

Randomized controlled trials, quasi-randomized controlled trials and cluster trials comparing salbutamol versus placebo or no treatment or any other drugs administered to infants born at 34 weeks' gestational age or more and less than three days of age with transient tachypnea of the newborn.

DATA COLLECTION AND ANALYSIS

For each of the included trials, two review authors independently extracted data (e.g. number of participants, birth weight, gestational age, duration of oxygen therapy, need for continuous positive airway pressure and need for mechanical ventilation, duration of mechanical ventilation, etc.) and assessed the risk of bias (e.g. adequacy of randomization, blinding, completeness of follow-up). The primary outcomes considered in this review were duration of oxygen therapy, need for continuous positive airway pressure and need for mechanical ventilation.

MAIN RESULTS

Three trials, which included 140 infants, met the inclusion criteria. All three trials compared a nebulized dose of salbutamol with placebo; in one of the three trials newborns were assigned to two different doses of the intervention. We found differences in the duration of oxygen therapy (mean difference (MD) -43.10 hours, 95% confidence interval (CI) -81.60 to -4.60). There were no differences in the need for continuous positive airway pressure (risk ratio (RR) 0.73, 95% CI 0.38 to 1.39; risk difference (RD) -0.15, 95% CI -0.45 to 0.16; 1 study, 46 infants) or the need for mechanical ventilation (RR 1.50, 95% CI 0.06 to 34.79; RD 0.03, 95% CI -0.08 to 0.14; 1 study, 46 infants). Tests for heterogeneity were not applicable for any of the analyses as only one study was included. Among secondary outcomes, we found no differences in terms of duration of hospital stay and tachypnea. The quality of the evidence was very low due to the imprecision of the estimates. One trial is ongoing.

AUTHORS' CONCLUSIONS

At present there is insufficient evidence to determine the efficacy and safety of salbutamol in the management of transient tachypnea of the newborn. The quality of evidence was low due to paucity of included trials, small sample sizes and overall poor methodologic quality.

The Effects of Inhaled β-Adrenergic Agonists in Transient Tachypnea of the Newborn

Aim. To investigate the efficacy of an inhaled β-adrenergic agonists in transient tachypnea of the newborn (TTN). Method. We retrospectively analyzed a cohort of 51 term infants (Group 1) and 37 term infants (Group 2) monitored in the newborn intensive care unit diagnosed with TTN. Infants in Group 1 received humidified oxygen alone, and infants in Group 2 were administered the inhaled β-2 agonist plus humidified oxygen. Results. TTN clinical respiratory assessment, respiratory rate, oxygen saturation values, need for supplemental oxygen therapy, blood gas PH, PO₂, and duration of hospitalization were significantly improved in infants in Group 2 as compared with infants in Group 1 (P < .05). No statistically significant difference was observed with regard to blood glucose, potassium, heart rate, and PCO₂ (P > .05). Conclusion. Inhaled β-adrenergic agonist added to humidified oxygen was found to improve clinical and laboratory parameters. We believe that further studies should be conducted with larger groups to demonstrate the efficacy of β-2 agonists in TTN patients.

Diabetes in pregnancy outcomes: a systematic review and proposed codification of definitions

Rising rates of diabetes in pregnancy have led to an escalation in research in this area. As in any area of clinical research, definitions of outcomes vary from study to study, making it difficult to compare research findings and draw conclusions. Our aim was to compile and create a repository of definitions, which could then be used universally. A systematic review of the literature was performed on published and ongoing randomized controlled trials in the area of diabetes in pregnancy between 01 Jan 2000 and 01 Jun 2012. Other sources included the World Health Organization and Academic Society Statements. The advice of experts was sought when appropriate definitions were lacking. Among the published randomized controlled trials on diabetes and pregnancy, 171 abstracts were retrieved, 64 full texts were reviewed and 53 were included. Among the ongoing randomized controlled trials published in ClinicalTrials.gov, 90 protocols were retrieved and 25 were finally included. The definitions from these were assembled and the final maternal definitions and foetal definitions were agreed upon by consensus. It is our hope that the definitions we have provided (i) will be widely used in the reporting of future studies in the area of diabetes in pregnancy, that they will (ii) facilitate future systematic reviews and formal meta analyses and (iii) ultimately improve outcomes for mothers and babies.

Neonatal resuscitation: evolving strategies

Birth asphyxia accounts for about 23% of the approximately 4 million neonatal deaths each year worldwide (Black et al., Lancet, 2010, 375(9730):1969-87). The majority of newborn infants require little assistance to undergo physiologic transition at birth and adapt to extrauterine life. Approximately 10% of infants require some assistance to establish regular respirations at birth. Less than 1% need extensive resuscitative measures such as chest compressions and approximately 0.06% require epinephrine (Wyllie et al. Resuscitation, 2010, 81 Suppl 1:e260–e287). Transition at birth is mediated by significant changes in circulatory and respiratory physiology. Ongoing research in the field of neonatal resuscitation has expanded our understanding of neonatal physiology enabling the implementation of improved recommendations and guidelines on how to best approach newborns in need for intervention at birth. Many of these recommendations are extrapolated from animal models and clinical trials in adults. There are many outstanding controversial issues in neonatal resuscitation that need to be addressed. This article provides a comprehensive and critical literature review on the most relevant and current research pertaining to evolving new strategies in neonatal resuscitation. The key elements to a successful neonatal resuscitation include ventilation of the lungs while minimizing injury, the judicious use of oxygen to improve pulmonary blood flow, circulatory support with chest compressions, and vasopressors and volume that would hasten return of spontaneous circulation. Several exciting new avenues in neonatal resuscitation such as delayed cord clamping, sustained inflation breaths, and alternate vasopressor agents are briefly discussed. Finally, efforts to improve resuscitative efforts in developing countries through education of basic steps of neonatal resuscitation are likely to decrease birth asphyxia and neonatal mortality.

Intra-hospital mortality among neonates transported by ambulance in Colombia

BACKGROUND

The aims of this study were to identify the main variables associated with intra-hospital mortality among patients transferred to a specialized neonatal care center, and to evaluate agreement and accuracy of referring and admission diagnoses.

METHODS

A 6 month observational study was conducted to obtain clinical variables for intra-hospital mortality among patients requiring interfacility transport. Association among variables was estimated using Poisson regression with robust variance. Agreement was evaluated between diagnosis before and after transfer using Cohen's kappa, sensitivity, specificity and Youden's I.

RESULTS

The study included 191 neonates, 12.57% of whom died. Increased mortality was associated with the Transport Risk Index of Physiologic Stability (TRIPS). The associated variables were as follows: TRIPS (adjusted prevalence ratio [aPR], 1.05; 95% confidence interval [CI]: 1.02-1.08), weight 1500-2499 g (aPR, 0.08; 95%CI: 0.01-0.40), weight >2500 g (aPR, 0.56; 95%CI: 0.02-0.19), cardiopathy (aPR, 0.20 95%CI: 0.05-0.75), congenital defects (aPR, 4.59; 95%CI: 0.97-21.82) and renal failure (aPR, 3.69; 95%CI: 1.26-10.78). Diagnosis remained unchanged for 71.15% of the neonates. The greatest differences were hyaline membrane disease (49.4%) followed by transient tachypnea (59.9%). Youden's I for referral diagnosis was 0.22 for transient tachypnea, 0.66-0.69 for cardiopathy, esophageal atresia and pneumonia, 0.72-0.74 for hyaline membrane disease and pulmonary hypertension, and >0.90 for the remaining diagnoses.

CONCLUSIONS

Weight <1500 g, renal failure, congenital defects (except congenital cardiopathies) and high TRIPS were associated with a higher risk of intra-hospital mortality. The findings suggest that improving transfer time and quality of care in ambulances would decrease mortality.

Mechanical stretch induces lung α-epithelial Na(+) channel expression

ABSTRACT During fetal development physiological stretching helps drive lung growth and maturation. At birth, the α-subunit of the alveolar epithelial sodium channel (α-ENaC) is a critical factor in helping to facilitate clearance of lung fluid during the perinatal period. The effects of stretch, however, on α-ENaC expression in the fetal lung have yet to be elucidated. In an effort to explore this question, we used both an in vitro cell culture model that exposes cells to repetitive cyclic stretch (CS) as well as an in vivo preterm animal model of mechanical ventilation (MV). We found that murine lung epithelial (MLE-12) cells exposed to repetitive CS showed a significant rise in α-ENaC mRNA expression. Total and cell-surface protein abundance of α-ENaC were also elevated after 24 h of CS. Stretch-induced increases in α-ENaC expression were suppressed in the presence of either actinomycin D or cycloheximide. Pharmacological inhibition of the extracellular signal-regulated protein kinase (ERK1/2) did not attenuate stretch-induced increases in α-ENaC protein, whereas inhibition of p38 MAPK or c-Jun NH2-terminal kinase (JNK) did. In 29-day preterm rabbits, alveolar stretching secondary to postnatal MV markedly elevated fetal lung α-ENaC expression compared to spontaneously breathing counterparts. In summary, our findings indicate that mechanical stretch promotes α-ENaC expression.

Nasal intermittent mandatory ventilation versus nasal continuous positive airway pressure for transient tachypnea of newborn: a randomized, prospective study

OBJECTIVE

To evaluate the efficacy of nasal intermittent mandatory ventilation (NIMV) in reducing the duration of respiratory distress compared with nasal continuous positive airway pressure (NCPAP) in transient tachypnea of the newborn (TTN).

PATIENT AND METHODS

In this randomized-prospective study, 40 infants with a gestational age ≥ 37 weeks and birth weight ≥ 2000 g with TTN were randomized to either nonsynchronized NIMV (n = 20) or NCPAP (n = 20). The primary end point was the reduction of the duration of respiratory distress. Secondary end points were the duration and level of oxygen supplementation, the incidence of complications such as pneumothorax, pneumonia and respiratory failure requiring entubation.

RESULTS

There were no significant difference in the duration of respiratory support (28.0 ± 19.2 h versus 32.2 ± 23.3 h, p = 0.231), O2 therapy (31.2 ± 15.6 h versus 29.0 ± 19.3 h, p = 0.187), duration of TTN (67.6 ± 36.5 h versus 63.3 ± 39.1 h, p = 0.480) and hospitalization (6.2 ± 2.6 d versus 5.4 ± 2.0 d, p = 0.330) between the groups. The rate of complications were not significantly different between the groups.

CONCLUSION

Our study indicates that NIMV is well tolerated and as effective as NCPAP in the treatment of TTN.

Neonatal stabilization and postresuscitation care

Neonatal mortality is a major health care concern worldwide. Neonatal resuscitation alone does not address most causes of neonatal mortality; caregivers need to be trained in both neonatal resuscitation and stabilization. Neonatal stabilization requires caregivers to evaluate whether babies are at-risk or unwell, to decide what interventions are required, and to act on those decisions. Several programs address neonatal stabilization in a variety of levels of care in both well-resourced and limited health care environments. This article suggests a shift in clinical, educational, and implementation science from a focus on resuscitation to one on the resuscitation-stabilization continuum.

The role of plasma N-terminal pro-B-type natriuretic peptide in predicting the severity of transient tachypnea of the newborn

BACKGROUND/AIM

Transient tachypnea of the newborn (TTN) is a consequence of inadequate neonatal lung fluid clearance. Natriuretic peptides play an important role in the regulation of extracellular fluid volume. The aim of the study was to investigate the relation between plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and TTN, and to find out its role in predicting disease severity.

METHODS

A prospective controlled study involving 67 infants with TTN and 33 controls ≥34 weeks gestational age was conducted. Study and control groups were compared for plasma NT-proBNP levels measured on the 6th, 24th, 72nd and 120th hours of life. Cardiac systolic functions were evaluated by echocardiography.

RESULTS

NT-proBNP levels were significantly higher in neonates with TTN compared to controls at 6th, 24th, 72nd and 120th hours (p<0.001). NT-proBNP levels at 24th and 72nd hours were significantly higher in infants with prolonged tachypnea (p=0.007 and p=0.03) and in those who required respiratory support (p=0.006 and p<0.001). Tachypnea duration was correlated with NT-proBNP levels at 24h (r=0.41, p=0.001). At a cut-off value of 6575 pg/ml, NT-proBNP had a sensitivity of 85% and specificity of 64% to predict mechanical ventilation requirement. Cardiac systolic functions were normal in all TTN patients.

CONCLUSION

Plasma NT-proBNP levels are increased in neonates with TTN. Measurement of plasma NT-proBNP can be useful for predicting infants who will have prolonged tachypnea and mechanical ventilation requirement.

Safety of recombinant human deoxyribonuclease as a rescue treatment for persistent atelectasis in newborns

BACKGROUND AND OBJECTIVE

Pulmonary problems are vitally important in newborns. Increased intense and mucoid secretions may lead to atelectasis, pulmonary infections, respiratory distress, prolonged mechanical ventilation or even death. The aim of this study was to evaluate the safety of recombinant human deoxyribonuclease (rhDNase) in the management of persistent atelectasis in term and preterm newborns, unresponsive to the conventional treatment.

DESIGN AND SETTING

Prospective study of patients admitted to a general community setting of a neonatal intensive care unit between December 2007 and December 2009.

PATIENTS AND METHODS

The study included 22 patients (12 premature and 10 term) who were admitted to the neonatal intensive care unit because of respiratory distress and developed atelectasis, and were unresponsive to conventional treatment. Nebulized rhDNase was administered to all patients at a dose of 1 mg/m2 twice daily for 3 days. In patients who did not respond to 3 days of treatment, endotracheal rhDNase was administered at a dose of 1 mg/m2. We assessed the clinical (respiratory rate and oxygen requirement) and radiologic responses (chest radiographic score), recurrence of atelectasis, the need for a repetitive treatment, and mortality rate.

RESULTS

A clinical and radiologic improvement of atelectasis was observed in 18 of 22 patients following 3 days of nebulized rhDNase treatment. Atelectasis relapsed in 4 patients. Following the administration of combined endotracheal and nebulized rhDNase treatment, an improvement of atelectasis was noted in all four recurrent cases. No adverse events were observed in patients because of the rhDNase treatment.

CONCLUSIONS

rhDNase treatment is a safe option and may be used as an effective method for the management of persistent atelectasis in newborns, which is resistant to other conventional treatment methods.

Inhaled beta-2 agonist salbutamol for the treatment of transient tachypnea of the newborn

OBJECTIVE

To evaluate the efficacy of inhaled salbutamol, a beta-2 adrenergic agonist, for the treatment of transient tachypnea of the newborn (TTN) and to determine whether inhaled salbutamol is safe in newborn infants.

STUDY DESIGN

Inhaled salbutamol or normal saline solution was administered to 54 infants with gestational ages ranging from 34 to 39 weeks and TTN. The response to salbutamol therapy was evaluated by determining respiratory rate, clinical score of TTN, level of respiratory support, and fraction of inspired oxygen before and at 30 minutes and 1 and 4 hours after salbutamol nebulization.

RESULTS

Among the 54 infants with TTN, 32 received salbutamol and 22 received normal saline solution. After one dose, the salbutamol group showed significant improvements in respiratory rate, clinical score of TTN, fraction of inspired oxygen, and level of respiratory support (P < .05). After treatment, the mean pH, partial pressure of arterial oxygen, and partial pressure of arterial carbon dioxide values were better in the salbutamol group when compared with the placebo group (P < .05). Duration of hospitalization in the neonatal intensive care unit was also shorter for the salbutamol group (P < .05).

CONCLUSION

Inhaled salbutamol treatment was effective with respect to both clinical and laboratory findings of TTN and without adverse events.

Lamellar bodies: platelet channel particles as predictors of respiratory distress syndrome (RDS) and of transient tachypnea of the newborn

OBJECTIVE

We aimed to find a single numeric cut-off point in order to predict respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN), through quantification of the lamellar bodies (LBs) count.

MATERIALS AND METHODS

Two hundred and twenty-seven single pregnancies delivered within 48 h from amniocentesis in a III level university hospital in a period between 1996 and 2007. LBs counts were determined by amniotic fluid (AF) sampling and after centrifugation in a commercially available Coulter counter. LBs counts were performed in order to predict the risk of neonatal RDS and also evaluated against the risk of TTN by means of the most suitable receiver operator characteristic (ROC) curve in order to predict RDS and TTN.

RESULTS

The best LBs cut-off to significantly predict TTN was ≤ 35,000/μL [sensitivity 86%, specificity 75%, positive predictive value (PPV) 22% and negative predictive value (NPV) at 96%]. An LBs count ≤ 32,000/μL was the best compromise between sensitivity and specificity in predicting RDS or TTN [sensitivity 86%, specificity 83%, PPV 37% and NPV at 97%].

CONCLUSIONS

The quantification of LBs is a reliable method, simple to execute, useful in predicting RDS, and may be useful in evaluating suspicion of TTN.

Effectiveness of antenatal corticosteroids in reducing respiratory disorders in late preterm infants: randomised clinical trial

OBJECTIVES

To determine the effectiveness of corticosteroids in reducing respiratory disorders in infants born at 34-36 weeks' gestation. Design Randomised triple blind clinical trial. Setting A large tertiary teaching hospital in northeast of Brazil. Participants Women at 34-36 weeks of pregnancy at risk of imminent premature delivery. Interventions Betamethasone 12 mg or placebo intramuscularly for two consecutive days. Main outcomes measures Primary outcome was the incidence of respiratory disorders (respiratory distress syndrome and transient tachypnoea of the newborn). Secondary outcomes included the need for ventilatory support, neonatal morbidity, and duration of stay in hospital.

RESULTS

320 women were randomised, 163 of whom were assigned to the treatment group and 157 to the controls. Final analysis included 143 and 130 infants, respectively. The rate of respiratory distress syndrome was low (two (1.4%) in the corticosteroid group; one (0.8%) in the placebo group; P = 0.54), while the rate of transient tachypnoea was high in both groups (34 (24%) v 29 (22%); P = 0.77). There was no reduction in the risk of respiratory morbidity with corticosteroid use even after adjustment for subgroups of gestational age (34-34(+6) weeks, 35-35(+6) weeks, and ≥ 36 weeks). The adjusted risk of respiratory morbidity was 1.12 (95% confidence interval 0.74 to 1.70). The need for ventilatory support was around 20% in both groups. There was no difference in neonatal morbidity (88 (62%) v 93 (72%); P = 0.08) or in the duration of stay in hospital between the two groups (5.12 v 5.22 days; P = 0.87). Phototherapy for jaundice was required less often in babies whose mothers received corticosteroids (risk ratio 0.63, 0.44 to 0.91).

CONCLUSIONS

Antenatal treatment with corticosteroids at 34-36 weeks of pregnancy does not reduce the incidence of respiratory disorders in newborn infants. Trial registration Clinical Trials NCT00675246.