Maternal intramuscular dexamethasone versus betamethasone before preterm birth (ASTEROID): a multicentre, double-blind, randomised controlled trial

Antenatal corticosteroids in Singapore: a clinical and scientific assessment

ABSTRACT

Preterm birth (PTB; delivery prior to 37 weeks' gestation) is the leading cause of early childhood death in Singapore today. Approximately 9% of Singaporean babies are born preterm; the PTB rate is likely to increase given the increased use of assisted reproduction technologies, changes in the incidence of gestational diabetes/high body mass index and the ageing maternal population. Antenatal administration of dexamethasone phosphate is a key component of the obstetric management of Singaporean women who are at risk of imminent preterm labour. Dexamethasone improves preterm outcomes by crossing the placenta to functionally mature the fetal lung. The dexamethasone regimen used in Singapore today affords a very high maternofetal drug exposure over a brief period of time. Drawing on clinical and experimental data, we reviewed the pharmacokinetic profile and pharmacodynamic effects of dexamethasone treatment regimen in Singapore, with a view to creating a development pipeline for optimising this critically important antenatal therapy.

Neurodevelopment Is Dependent on Maternal Diet: Placenta and Brain Glucose Transporters GLUT1 and GLUT3

Glucose is the primary energy source for most mammalian cells and its transport is affected by a family of facilitative glucose transporters (GLUTs) encoded by the SLC2 gene. GLUT1 and GLUT3, highly expressed isoforms in the blood-brain barrier and neuronal membranes, respectively, are associated with multiple neurodevelopmental disorders including epilepsy, dyslexia, ADHD, and autism spectrum disorder (ASD). Dietary therapies, such as the ketogenic diet, are widely accepted treatments for patients with the GLUT1 deficiency syndrome, while ameliorating certain symptoms associated with GLUT3 deficiency in animal models. A ketogenic diet, high-fat diet, and calorie/energy restriction during prenatal and postnatal stages can also alter the placental and brain GLUTs expression with long-term consequences on neurobehavior. This review focuses primarily on the role of diet/energy perturbations upon GLUT isoform-mediated emergence of neurodevelopmental and neurodegenerative disorders.

Antenatal corticosteroids: an updated assessment of anticipated benefits and potential risks

Antenatal steroid therapy is increasingly central to the obstetrical management of women at imminent risk of preterm birth. For women likely to deliver between 24 and 34 weeks' gestation, antenatal steroid therapy is the standard of care, conferring sizable benefits and few risks in high-resource environments when appropriately targeted. Recent studies have focused on antenatal steroid use in periviable and late preterm populations, and in term cesarean deliveries. As a result, antenatal steroid therapy has now been applied from 22 to 39+6 weeks of estimated gestational age. There is also an increased appreciation that the vast majority of randomized control data informing the use of antenatal steroids are derived from predominantly high-resource, White populations. Accordingly, a sizable amount of work has recently been undertaken to test how to safely use antenatal steroids in low- and middle-resource environments, wherein the often high rates of preterm birth make these low-cost, easily administered interventions an attractive proposition. It is likely underappreciated by the obstetrical and neonatal communities that the overall efficacy of antenatal steroid therapy is highly variable (including when preterm risk is accurately assessed), the treatment regimens used are largely arbitrary, dosing is suprapharmacologic for effect, and the benefit-risk balance is significantly and differentially modified by gestation. It is also very likely that the patients consenting to receive these treatments are similarly unaware of the complex balance of potential benefits and harms. Although a small number of follow-up studies present a generally benign picture of long-term antenatal steroid risk, several large, population-based retrospective studies have identified associations between antenatal steroid use, childhood mental disease, and newborn infections that warrant urgent attention. Of particular contemporary importance are emergent efforts to optimize antenatal steroid regimens on the basis of the pharmacokinetics and pharmacodynamics of the agents themselves, the need for better targeting of these potent drugs, and clear articulation of the potential benefits and harms of antenatal steroid use at differing stages of pregnancy and in different delivery contexts.

Sequential embryo transfer combined with intrauterine perfusion improved pregnancy outcomes in patients with recurrent implantation failure

OBJECTIVE

To compare the application of sequential embryo transfer, cleavage embryo transfer, and blastocyst transfer combined with intrauterine perfusion in frozen-thawed embryo transfer cycles in patients with recurrent implantation failure to provide a reference for reproductive clinicians.

METHODS

The 166 patients who underwent frozen-thawed embryo transfer due to recurrent implantation failure in the reproductive center from January 2021 to March 2022 were retrospectively analyzed. According to the different embryos transferred, they were divided into cleavage embryo transfer groups (72 cases in Group A), blastocyst transfer group (29 cases in Group B), and sequential transfer group (65 cases in Group C). All three groups were treated with intrauterine perfusion 5 days before embryo transfer. The general data and clinical pregnancy outcome indicators, such as embryo implantation rate, clinical pregnancy rate, ongoing pregnancy rate, live birth rate, twin rate, were compared among the three groups.

RESULTS

The embryo implantation rate (53.1%), clinical pregnancy rate (76.9%), ongoing pregnancy rate (67.7%) and live birth rate(66.15%) in the sequential transfer group were significantly higher than those in the other two groups (P < 0.05), and the ectopic pregnancy rate was lower in the sequential transfer group.

CONCLUSION

Sequential transfer combined with intrauterine perfusion partially improves clinical pregnancy outcomes and reduces the risk of ectopic pregnancy in frozen embryo cycle transfers in patients with recurrent implantation failure, which may be a favourable transfer reference strategy for patients with recurrent implantation failure.

European guidelines on perinatal care: corticosteroids for women at risk of preterm birth

of recommendationsCorticosteroids should be administered to women at a gestational age between 24⁺⁰ and 33⁺⁶weeks, when preterm birth is anticipated in the next seven days, as these have been consistently shown to reduce neonatal mortality and morbidity. (Strong-quality evidence; strong recommendation). In selected cases, extension of this period up to 34⁺⁶weeks may be considered (Expert opinion). Optimal benefits are found in infants delivered within 7 days of corticosteroid administration. Even a single-dose administration should be given to women with imminent preterm birth, as this is likely to improve neurodevelopmental outcome (Moderate-quality evidence; conditional recommendation).Either betamethasone (12 mg administered intramuscularly twice, 24-hours apart) or dexamethasone (6 mg administered intramuscularly in four doses, 12-hours apart, or 12 mg administered intramuscularly twice, 24-hours apart), may be used (Moderate-quality evidence; Strong recommendation). Administration of two "all" doses is named a "course of corticosteroids".Administration between 22⁺⁰ and 23⁺⁶weeks should be considered when preterm birth is anticipated in the next seven days and active newborn life-support is indicated, taking into account parental wishes. Clear survival benefit has been observed in these cases, but the impact on short-term neurological and respiratory function, as well as long-term neurodevelopmental outcome is still unclear (Low/moderate-quality evidence; Weak recommendation).Administration between 34 + 0 and 34 + 6 weeks should only be offered to a few selected cases (Expert opinion). Administration between 35⁺⁰ and 36⁺⁶weeks should be restricted to prospective randomized trials. Current evidence suggests that although corticosteroids reduce the incidence of transient tachypnea of the newborn, they do not affect the incidence of respiratory distress syndrome, and they increase neonatal hypoglycemia. Long-term safety data are lacking (Moderate quality evidence; Conditional recommendation).Administration in pregnancies beyond 37⁺⁰weeks is not indicated, even for scheduled cesarean delivery, as current evidence does not suggest benefit and the long-term effects remain unknown (Low-quality evidence; Conditional recommendation).Administration should be given in twin pregnancies, with the same indication and doses as for singletons. However, existing evidence suggests that it should be reserved for pregnancies at high-risk of delivering within a 7-day interval (Low-quality evidence; Conditional recommendation). Maternal diabetes mellitus is not a contraindication to the use of antenatal corticosteroids (Moderate quality evidence; Strong recommendation).A single repeat course of corticosteroids can be considered in pregnancies at less than 34⁺⁰weeks gestation, if the previous course was completed more than seven days earlier, and there is a renewed risk of imminent delivery (Low-quality evidence; Conditional recommendation).

Respiratory benefit in preterm lambs is progressively lost when the concentration of fetal plasma betamethasone is titrated below two nanograms per milliliter

Antenatal steroid therapy is the standard of care for women at imminent risk of preterm delivery. Current dosing regimens use suprapharmacological doses to achieve extended fetal steroid exposures. We aimed to determine the lowest fetal plasma betamethasone concentration sufficient to achieve functional preterm lung maturation. Ewes with single fetuses underwent surgery to install a fetal jugular catheter. Adopting a stepwise design, ewes were randomized to either a saline-only group (negative control group; n = 9) or one of four betamethasone treatment groups. Each betamethasone group fetus received a fetal intravenous infusion to target a constant plasma betamethasone level of either 1) 2 ng/mL (2 ng/mL positive control group, n = 9); 2) 1 ng/mL, (1 ng/mL group, n = 10); 3) 0.5 ng/mL (0.5 ng/mL group, n = 10); or 4) 0.25 ng/mL (0.25 ng/mL group, n = 10). Fetuses were infused for 48 h, delivered, and ventilated. The positive control group, negative control group, and mid-point 0.5 ng/mL group animals were tested first. An interim analysis informed the final betamethasone group tested. Positive control group animals had large, statistically significant improvements in respiratory function. Based on an interim analysis, the 1.0 ng/mL group was studied in favor of the 0.25 ng/mL group. Treatment efficacy was progressively lost at plasma betamethasone concentrations lower than 2 ng/mL. We demonstrated that the acute respiratory benefit conveyed by antenatal steroid exposure in the fetal sheep is progressively lost when constant fetal plasma betamethasone concentrations are reduced below a targeted value of 2 ng/mL.NEW & NOTEWORTHY Lung maturation benefits in preterm lambs were progressively lost when fetal plasma betamethasone concentrations fell below 2 ng/mL. The effective floor threshold for a robust, lung-maturing exposure likely lies between 1 and 2 ng betamethasone per milliliter of plasma. Hypothalamic pituitary adrenal axis signaling and immunocyte populations remained materially disrupted at subtherapeutic steroid concentrations. These data demonstrate the potential to improve antenatal steroid therapy using reduced dose regimens informed by glucocorticoid pharmacokinetics and pharmacodynamics.

Association between antenatal corticosteroid treatment and severe adverse events in pregnant women

BACKGROUND

Antenatal corticosteroids are considered the standard of care for pregnant women at risk for preterm birth, but studies examining their potential risks are scarce. We aimed to estimate the associations of antenatal corticosteroids with three severe adverse events: sepsis, heart failure, and gastrointestinal bleeding, in pregnant women.

METHODS

Of 2,157,321 pregnant women, 52,119 at 24 weeks 0/7 days to 36 weeks 6/7 days of gestation were included in this self-controlled case series study during the study period of 2009-2018. We estimated incidence rates of three severe adverse events: sepsis, heart failure, and gastrointestinal bleeding. Conditional Poisson regression was used to calculate incidence rate ratios (IRRs) for comparing incidence rates of the adverse events in each post-treatment period compared to those during the baseline period among pregnant women exposed to a single course of antenatal corticosteroid treatment.

RESULTS

Among 52,119 eligible participants who received antenatal corticosteroid treatment, the estimated incidence rates per 1000 person-years were 0.76 (95% confidence interval (CI): 0.69-0.83) for sepsis, 0.31 (95% CI: 0.27-0.36) for heart failure, and 11.57 (95% CI: 11.27-11.87) for gastrointestinal bleeding. The IRRs at 5 ~ 60 days after administration of antenatal corticosteroids were 5.91 (95% CI: 3.10-11.30) for sepsis and 4.45 (95% CI: 2.63-7.55) for heart failure, and 1.26 (95% CI: 1.02-1.55) for gastrointestinal bleeding; and the IRRs for days 61 ~ 180 were 2.00 (95% CI: 1.01-3.96) for sepsis, 3.65 (95% CI: 2.14-6.22) for heart failure, and 1.81 (95% CI: 1.56-2.10) for gastrointestinal bleeding.

CONCLUSIONS

This nationwide population-based study suggests that a single course of antenatal corticosteroids is significantly associated with a 1.3- to 5.9-fold increased risk of sepsis, heart failure, and gastrointestinal bleeding in pregnant women. Maternal health considerations, including recommendations for adverse event monitoring, should be included in future guidelines for antenatal corticosteroid treatment.

Molecular mechanisms underlying adverse effects of dexamethasone and betamethasone in the developing cardiovascular system

Antenatal glucocorticoids accelerate fetal lung maturation and reduce mortality in preterm babies but can trigger adverse effects on the cardiovascular system. The mechanisms underlying off-target effects of the synthetic glucocorticoids mostly used, Dexamethasone (Dex) and Betamethasone (Beta), are unknown. We investigated effects of Dex and Beta on cardiovascular structure and function, and underlying molecular mechanism using the chicken embryo, an established model system to isolate effects of therapy on the developing heart and vasculature, independent of effects on the mother or placenta. Fertilized eggs were treated with Dex (0.1 mg kg-1 ), Beta (0.1 mg kg-1 ), or water vehicle (Control) on embryonic day 14 (E14, term = 21 days). At E19, biometry, cardiovascular function, stereological, and molecular analyses were determined. Both glucocorticoids promoted growth restriction, with Beta being more severe. Beta compared with Dex induced greater cardiac diastolic dysfunction and also impaired systolic function. While Dex triggered cardiomyocyte hypertrophy, Beta promoted a decrease in cardiomyocyte number. Molecular changes of Dex on the developing heart included oxidative stress, activation of p38, and cleaved caspase 3. In contrast, impaired GR downregulation, activation of p53, p16, and MKK3 coupled with CDK2 transcriptional repression linked the effects of Beta on cardiomyocyte senescence. Beta but not Dex impaired NO-dependent relaxation of peripheral resistance arteries. Beta diminished contractile responses to potassium and phenylephrine, but Dex enhanced peripheral constrictor reactivity to endothelin-1. We conclude that Dex and Beta have direct differential detrimental effects on the developing cardiovascular system.

Interventions to Reduce Severe Brain Injury Risk in Preterm Neonates: A Systematic Review and Meta-analysis

Importance

Interventions to reduce severe brain injury risk are the prime focus in neonatal clinical trials.

Objective

To evaluate multiple perinatal interventions across clinical settings for reducing the risk of severe intraventricular hemorrhage (sIVH) and cystic periventricular leukomalacia (cPVL) in preterm neonates.

Data Sources

MEDLINE, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases were searched from inception until September 8, 2022, using prespecified search terms and no language restrictions.

Study Selection

Randomized clinical trials (RCTs) that evaluated perinatal interventions, chosen a priori, and reported 1 or more outcomes (sIVH, cPVL, and severe brain injury) were included.

Data Extraction and Synthesis

Two co-authors independently extracted the data, assessed the quality of the trials, and evaluated the certainty of the evidence using the Cochrane GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Fixed-effects pairwise meta-analysis was used for data synthesis.

Main Outcomes and Measures

The 3 prespecified outcomes were sIVH, cPVL, and severe brain injury.

Results

A total of 221 RCTs that assessed 44 perinatal interventions (6 antenatal, 6 delivery room, and 32 neonatal) were included. Meta-analysis showed with moderate certainty that antenatal corticosteroids were associated with small reduction in sIVH risk (risk ratio [RR], 0.54 [95% CI, 0.35-0.82]; absolute risk difference [ARD], -1% [95% CI, -2% to 0%]; number needed to treat [NNT], 80 [95% CI, 48-232]), whereas indomethacin prophylaxis was associated with moderate reduction in sIVH risk (RR, 0.64 [95% CI, 0.52-0.79]; ARD, -5% [95% CI, -8% to -3%]; NNT, 20 [95% CI, 13-39]). Similarly, the meta-analysis showed with low certainty that volume-targeted ventilation was associated with large reduction in risk of sIVH (RR, 0.51 [95% CI, 0.36-0.72]; ARD, -9% [95% CI, -13% to -5%]; NNT, 11 [95% CI, 7-23]). Additionally, early erythropoiesis-stimulating agents (RR, 0.68 [95% CI, 0.57-0.83]; ARD, -3% [95% CI, -4% to -1%]; NNT, 34 [95% CI, 22-67]) and prophylactic ethamsylate (RR, 0.68 [95% CI, 0.48-0.97]; ARD, -4% [95% CI, -7% to 0%]; NNT, 26 [95% CI, 13-372]) were associated with moderate reduction in sIVH risk (low certainty). The meta-analysis also showed with low certainty that compared with delayed cord clamping, umbilical cord milking was associated with a moderate increase in sIVH risk (RR, 1.82 [95% CI, 1.03-3.21]; ARD, 3% [95% CI, 0%-6%]; NNT, -30 [95% CI, -368 to -16]).

Conclusions and Relevance

Results of this study suggest that a few interventions, including antenatal corticosteroids and indomethacin prophylaxis, were associated with reduction in sIVH risk (moderate certainty), and volume-targeted ventilation, early erythropoiesis-stimulating agents, and prophylactic ethamsylate were associated with reduction in sIVH risk (low certainty) in preterm neonates. However, clinicians should carefully consider all of the critical factors that may affect applicability in these interventions, including certainty of the evidence, before applying them to clinical practice.

Partially clustered designs for clinical trials: Unifying existing designs using consistent terminology

INTRODUCTION

Clinical trial designs based on the assumption of independent observations are well established. Clustered clinical trial designs, where all observational units belong to a cluster and outcomes within clusters are expected to be correlated, have also received considerable attention. However, many clinical trials involve partially clustered data, where only some observational units belong to a cluster. Examples of such trials occur in neonatology, where participants include infants from both singleton and multiple births, and ophthalmology, where one or two eyes per participant may need treatment. Partial clustering can also arise in trials of group-based treatments (e.g. group education or counselling sessions) or treatments administered individually by a discrete number of health care professionals (e.g. surgeons or physical therapists), when this is compared to an unclustered control arm. Trials involving partially clustered data have received limited attention in the literature and the current lack of standardised terminology may be hampering the development and dissemination of methods for designing and analysing these trials.

METHODS AND EXAMPLES

In this article, we present an overarching definition of partially clustered trials, bringing together several existing trial designs including those for group-based treatments, clustering due to facilitator effects and the re-randomisation design. We define and describe four types of partially clustered trial designs, characterised by whether the clustering occurs pre-randomisation or post-randomisation and, in the case of pre-randomisation clustering, by the method of randomisation that is used for the clustered observations (individual randomisation, cluster randomisation or balanced randomisation within clusters). Real life examples are provided to highlight the occurrence of partially clustered trials across a variety of fields. To assess how partially clustered trials are currently reported, we review published reports of partially clustered trials.

DISCUSSION

Our findings demonstrate that the description of these trials is often incomplete and the terminology used to describe the trial designs is inconsistent, restricting the ability to identify these trials in the literature. By adopting the definitions and terminology presented in this article, the reporting of partially clustered trials can be substantially improved, and we present several recommendations for reporting these trial designs in practice. Greater awareness of partially clustered trials will facilitate more methodological research into their design and analysis, ultimately improving the quality of these trials.

The role of antenatal corticosteroids in twin pregnancy

Twin pregnancy was associated with significantly higher rates of adverse neonatal and perinatal outcomes. One of the underlying causes is that twins are prone to preterm birth. Antenatal corticosteroids are widely used for reducing the incidence of neonatal respiratory distress syndrome initially and other neonatal mortality and morbidities subsequently. As it is widely used as a prophylactic treatment for potential premature births, there remain controversies of issues relating to twin gestations, including window for opportunity, timing of use, repeat course, optimal administration-to-delivery intervals, dosage, and type of corticosteroid. Thus, we present a thorough review of antenatal corticosteroids usage in twin gestation, emphasizing the aforementioned issues and attempting to offer direction for future investigation and clinical practice.

Characteristics and Outcomes of Critically Ill Pregnant/Postpartum Women with COVID-19 Pneumonia in Western Balkans, The Republic of Srpska Report

Background and Objectives: Coronavirus disease 2019 (COVID-19) is a novel infectious disease that has spread worldwide. As of 5 March 2020, the COVID-19 pandemic has resulted in approximately 111,767 cases and 6338 deaths in the Republic of Srpska and 375,554 cases and 15,718 deaths in Bosnia and Herzegovina. Our objective in the present study was to determine the characteristics and outcomes of critically ill pregnant/postpartum women with COVID-19 in the Republic of Srpska. Materials and Methods: The retrospective observational study of prospectively collected data included all critically ill pregnant/postpartum women with COVID-19 in a university-affiliated hospital between 1 April 2020 and 1 April 2022. Infection was confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) from nasopharyngeal swab specimens and respiratory secretions. Patients' demographics, clinical and laboratory data, pharmacotherapy, and neonatal outcomes were analysed. Results: Out of the 153 registered pregnant women with COVID-19 treated at the gynaecology department of the University Clinical Centre of the Republic of Srpska, 19 (12.41%) critically ill pregnant/postpartum women (median age of 36 (IQR, 29-38) years) were admitted to the medical intensive care unit (MICU). The mortality rate was 21.05% (four patients) during the study period. Of all patients (19), 14 gave birth (73.68%), and 4 (21.05%) were treated with veno-venous extracorporeal membrane oxygenation (vvECMO). Conclusions: Fourteen infants were born prematurely and none of them died during hospitalisation. A high mortality rate was detected among the critically ill pregnant/postpartum patients treated with mechanical ventilation and vvECMO in the MICU. The preterm birth rate was high in patients who required a higher level of life support (vvECMO and ventilatory support).

The complex challenge of antenatal steroid therapy nonresponsiveness

Antenatal steroid therapy is standard care for women at imminent risk of preterm delivery. When deliveries occur within 7 days of treatment, antenatal steroid therapy reduces the risk of neonatal death and improves preterm outcomes by exerting diverse developmental effects on the fetal organs, in particular the preterm lung and cardiovascular system. There is, however, sizable variability in antenatal steroid treatment efficacy, and an important percentage of fetuses exposed to antenatal steroid therapy do not respond sufficiently to derive benefit. Respiratory distress syndrome, for example, is a central metric of clinical trials to assess antenatal steroid outcomes. In the present analysis, we addressed the concept of antenatal steroid nonresponsiveness, and defined a failed or suboptimal response to antenatal steroids as death or a diagnosis of respiratory distress syndrome following treatment. For deliveries at 24 to 35 weeks' gestation, the number needed to treat to prevent 1 case of respiratory distress syndrome was 19 (95% confidence interval, 14-28). Reflecting gestation-dependent risk, for deliveries at >34 weeks' gestation the number needed to treat was 55 (95% confidence interval, 30-304), whereas for elective surgical deliveries at term this number was 106 (95% confidence interval, 61-421). We reviewed data from clinical and animal studies investigating antenatal steroid therapy to highlight the significant incidence of antenatal steroid therapy nonresponsiveness (ie, residual mortality or respiratory distress syndrome after treatment), and the potential mechanisms underpinning this outcome variability. The origins of this variability may be related to both the manner in which the therapy is applied (ie, the treatment regimen itself) and factors specific to the individual (ie, genetic variation, stress, infection). The primary aims of this review were: (1) to emphasize to the obstetrical and neonatal communities the extent of antenatal steroid response variability and its potential impact; (2) to propose approaches by which antenatal steroid therapy may be better applied to improve overall benefit; and (3) to stimulate further research toward the empirical optimization of this important antenatal therapy.

Changes in the live birth profile in Henan, China: A hospital registry-based study

BACKGROUND

Preterm complications and neonatal asphyxia are the leading causes of death in those under 5 years of age. However, little information exists for the province of Henan, China. The purpose of this study was to explore changes in the live birth profile in a provincial hospital over the past 32 years in Henan, China.

METHODS

A retrospective analysis was conducted to reveal the characteristics of live neonates from 1987 to 2018.

RESULTS

There were 118 253 live births during the period, including 19 798 (16.74%) preterm births. The neonatal death rate was 6.45‰, and the top risk factor was preterm birth complications and birth asphyxia. Before 1998, neonatal death occurred primarily among term infants. Between 1999 and 2018, preterm infants, especially extreme and very preterm infants with very low birthweight, constituted more than half of all mortalities, and the preterm birth rate increased from 5.94% in 1999 to 16.69% in 2018. The risk factors associated with preterm birth were being male (aOR = 1.18, P < 0.001), advanced maternal age (>35 years old; aOR = 1.08, P = 0.008), gravidity ≥2 (aOR = 1.15, P < 0.001), parity ≥2 (aOR = 1.50, P < 0.001), placenta previa (aOR = 7.41, P < 0.001), twin or multiple births (aOR = 10.63, P < 0.001), hypertension (aOR = 2.08, P < 0.001), and rupture of membrane (aOR = 5.03, P < 0.001).

CONCLUSIONS

The preterm birth rate has increased over the past 32 years from 4.98% to 16.69% in a provincial hospital in China. Preterm birth was the leading reason for neonatal death, and birth asphyxia was the major risk factor for death in term infants.

Different corticosteroids and regimens for accelerating fetal lung maturation for babies at risk of preterm birth

BACKGROUND

Despite the widespread use of antenatal corticosteroids to prevent respiratory distress syndrome (RDS) in preterm infants, there is currently no consensus as to the type of corticosteroid to use, dose, frequency, timing of use or the route of administration.  OBJECTIVES: To assess the effects on fetal and neonatal morbidity and mortality, on maternal morbidity and mortality, and on the child and adult in later life, of administering different types of corticosteroids (dexamethasone or betamethasone), or different corticosteroid dose regimens, including timing, frequency and mode of administration.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (9 May 2022) and reference lists of retrieved studies.

SELECTION CRITERIA

We included all identified published and unpublished randomised controlled trials or quasi-randomised controlled trials comparing any two corticosteroids (dexamethasone or betamethasone or any other corticosteroid that can cross the placenta), comparing different dose regimens (including frequency and timing of administration) in women at risk of preterm birth. We planned to exclude cross-over trials and cluster-randomised trials. We planned to include studies published as abstracts only along with studies published as full-text manuscripts.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies. Data were checked for accuracy. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 11 trials (2494 women and 2762 infants) in this update, all of which recruited women who were at increased risk of preterm birth or had a medical indication for preterm birth. All trials were conducted in high-income countries. Dexamethasone versus betamethasone Nine trials (2096 women and 2319 infants) compared dexamethasone versus betamethasone. All trials administered both drugs intramuscularly, and the total dose in the course was consistent (22.8 mg or 24 mg), but the regimen varied. We assessed one new study to have no serious risk of bias concerns for most outcomes, but other studies were at moderate (six trials) or high (two trials) risk of bias due to selection, detection and attrition bias. Our GRADE assessments ranged between high- and low-certainty, with downgrades due to risk of bias and imprecision.  Maternal outcomes The only maternal primary outcome reported was chorioamnionitis (death and puerperal sepsis were not reported). Although the rate of chorioamnionitis was lower with dexamethasone, we did not find conclusive evidence of a difference between the two drugs (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.48 to 1.06; 1 trial, 1346 women; moderate-certainty evidence). The proportion of women experiencing maternal adverse effects of therapy was lower with dexamethasone; however, there was not conclusive evidence of a difference between interventions (RR 0.63, 95% CI 0.35 to 1.13; 2 trials, 1705 women; moderate-certainty evidence). Infant outcomes We are unsure whether the choice of drug makes a difference to the risk of any known death after randomisation, because the 95% CI was compatible with both appreciable benefit and harm with dexamethasone (RR 1.03, 95% CI 0.66 to 1.63; 5 trials, 2105 infants; moderate-certainty evidence). The choice of drug may make little or no difference to the risk of RDS (RR 1.06, 95% CI 0.91 to 1.22; 5 trials, 2105 infants; high-certainty evidence). While there may be little or no difference in the risk of intraventricular haemorrhage (IVH), there was substantial unexplained statistical heterogeneity in this result (average (a) RR 0.71, 95% CI 0.28 to 1.81; 4 trials, 1902 infants; I² = 62%; low-certainty evidence). We found no evidence of a difference between the two drugs for chronic lung disease (RR 0.92, 95% CI 0.64 to 1.34; 1 trial, 1509 infants; moderate-certainty evidence), and we are unsure of the effects on necrotising enterocolitis, because there were few events in the studies reporting this outcome (RR 5.08, 95% CI 0.25 to 105.15; 2 studies, 441 infants; low-certainty evidence). Longer-term child outcomes Only one trial consistently followed up children longer term, reporting  at two years' adjusted age. There is probably little or no difference between dexamethasone and betamethasone in the risk of neurodevelopmental disability at follow-up (RR 1.02, 95% CI 0.85 to 1.22; 2 trials, 1151 infants; moderate-certainty evidence). It is unclear whether the choice of drug makes a difference to the risk of visual impairment (RR 0.33, 95% CI 0.01 to 8.15; 1 trial, 1227 children; low-certainty evidence). There may be little or no difference between the drugs for hearing impairment (RR 1.16, 95% CI 0.63 to 2.16; 1 trial, 1227 children; moderate-certainty evidence), motor developmental delay (RR 0.89, 95% CI 0.66 to 1.20; 1 trial, 1166 children; moderate-certainty evidence) or intellectual impairment (RR 0.97, 95% CI 0.79 to 1.20; 1 trial, 1161 children; moderate-certainty evidence). However, the effect estimate for cerebral palsy is compatible with both an important increase in risk with dexamethasone, and no difference between interventions (RR 2.50, 95% CI 0.97 to 6.39; 1 trial, 1223 children; low-certainty evidence). No trials followed the children beyond early childhood. Comparisons of different preparations and regimens of corticosteroids We found three studies that included a comparison of a different regimen or preparation of either dexamethasone or betamethasone (oral dexamethasone 32 mg versus intramuscular dexamethasone 24 mg; betamethasone acetate plus phosphate versus betamethasone phosphate; 12-hourly betamethasone versus 24-hourly betamethasone). The certainty of the evidence for the main outcomes from all three studies was very low, due to  small sample size and  risk of bias. Therefore, we were limited in our ability to draw conclusions from any of these studies.

AUTHORS' CONCLUSIONS

Overall, it remains unclear whether there are important differences between dexamethasone and betamethasone, or between one regimen and another.  Most trials compared dexamethasone versus betamethasone. While for most infant and early childhood outcomes there may be no difference between these drugs, for several important outcomes for the mother, infant and child the evidence was inconclusive and did not rule out significant benefits or harms. The evidence on different antenatal corticosteroid regimens was sparse, and does not support the use of one particular corticosteroid regimen over another.

The variation of antenatal corticosteroids administration for the singleton preterm birth in China, 2017 to 2018

Background

The administration of antenatal corticosteroids (ACS) to women who are at risk of preterm birth has been proven to reduce not only the mortality, but also the major morbidities of the preterm infants. The rate of ACS and the risk factors associated with ACS use in Chinese population is unclear. This study aimed to investigate the rate of ACS use and the associated perinatal factors in the tertiary maternal centers of China.

Methods

Data for this retrospective observational study came from a clinical database of preterm infants established by REIN-EPIQ trial. All infants born at < 34 weeks of gestation and admitted to 18 tertiary maternal centers in China from 2017 to 2018 were enrolled. Any dose of dexamethasone was given prior to preterm delivery was recorded and the associated perinatal factors were analyzed.

Results

The rate of ACS exposure in this population was 71.2% (range 20.2 – 92%) and the ACS use in these 18 maternal centers varied from 20.2 to 92.0% in this period. ACS exposure was higher among women with preeclampsia, caesarean section delivery, antibiotic treatment and who delivered infants with lower gestational age and small for gestational age. ACS use was highest in the 28–31 weeks gestational age group, and lowest in the under 26 weeks of gestational age group (x² = 65.478, P < 0.001). ACS exposure was associated with lower odds of bronchopulmonary dysplasia or death (OR, 0.778; 95% CI 0.661 to 0.916) and invasive respiration requirement (OR, 0.668; 95% CI 0.585 to 0.762) in this population.

Conclusion

The ACS exposure was variable among maternity hospitals and quality improvement of ACS administration is warranted.

Respiratory distress syndrome management in resource limited settings-Current evidence and opportunities in 2022

The complications of prematurity are the leading cause of neonatal mortality worldwide, with the highest burden in the low- and middle-income countries of South Asia and Sub-Saharan Africa. A major driver of this prematurity-related neonatal mortality is respiratory distress syndrome due to immature lungs and surfactant deficiency. The World Health Organization's Every Newborn Action Plan target is for 80% of districts to have resources available to care for small and sick newborns, including premature infants with respiratory distress syndrome. Evidence-based interventions for respiratory distress syndrome management exist for the peripartum, delivery and neonatal intensive care period- however, cost, resources, and infrastructure limit their availability in low- and middle-income countries. Existing research and implementation gaps include the safe use of antenatal corticosteroid in non-tertiary settings, establishing emergency transportation services from low to high level care facilities, optimized delivery room resuscitation, provision of affordable caffeine and surfactant as well as implementing non-traditional methods of surfactant administration. There is also a need to optimize affordable continuous positive airway pressure devices able to blend oxygen, provide humidity and deliver reliable pressure. If the high prematurity-related neonatal mortality experienced in low- and middle-income countries is to be mitigated, a concerted effort by researchers, implementers and policy developers is required to address these key modalities.

A Growing Dilemma: Antenatal Corticosteroids and Long-Term Consequences

OBJECTIVE

A single course of synthetic antenatal corticosteroids is standard care for women considered to be at risk for preterm birth before 34 weeks of gestation. While the intended target is the fetal lung, the fetal brain contains remarkably high levels of glucocorticoid receptors in structures critical in the regulation of behavior and endocrine function. Negative programming signals may occur which can lead to permanent maladaptive changes and predispose the infant/child to an increased risk in physical, mental, and developmental disorders.

METHODS

Framed around these areas of concerns for physical, mental, and developmental disorders, this narrative review drew on studies (animal and clinical), evaluating the long-term effects of antenatal corticosteroids to present the case that a more targeted approach to the use of antenatal corticosteroids for the betterment of the fetus urgently needed.

RESULTS

Studies raised concerns about the potential negative long-term consequences, especially for the exposed fetus who was born beyond the period of the greatest benefit from antenatal corticosteroids. The long-term consequences are more subtle in nature and usually manifest later in life, often beyond the scope of most clinical trials.

CONCLUSION

Continued research is needed to identify sufficient safety data, both short term and long term. Caution in the use of antenatal corticosteroids should be exercised while additional work is undertaken to optimize dosing strategies and better identify women at risk of preterm birth prior to administration of antenatal corticosteroids.

KEY POINTS

· A single-course ACS is a remarkable therapy with substantial benefits.. · There is a potential of long-term neurodevelopmental consequences in the ACS-exposed fetus.. · There is a need to improve dosing strategies and identification of appropriate at risk women..

Current evidence for prenatal and postnatal corticosteroids in preterm infants

Antenatal corticosteroids undoubtedly save many lives and improve the quality of many others. However, the currently accepted dosage schedule has been in place since 1972, and recent studies have suggested that beneficial effects may be seen with less. Most but not all studies of long-term outcome show no adverse effects. The use of antenatal corticosteroids in women with COVID-19 raises important questions regarding potential risks and benefits. However, currently, most authorities recommend continuing according to published guidelines. With regard to postnatal corticosteroids, alternatives to systemic dexamethasone, the somewhat tainted standard of care, show promise in preventing bronchopulmonary dysplasia without adverse effects. Systemic hydrocortisone and inhaled corticosteroids are of note. The mixture of surfactant and corticosteroids deserves particular attention in the coming years.

Maternal and infant morbidity following administration of repeat dexamethasone or betamethasone prior to preterm birth: A secondary analysis of the ASTEROID Trial

BACKGROUND

Clinical practice guidelines recommend administering antenatal corticosteroids (ACS), either betamethasone or dexamethasone, to women at risk of preterm birth at less than 35 weeks' gestation. If women remain at risk of preterm birth seven or more days after an initial course of ACS, most guidelines recommend administration of a repeat dose(s). No randomised trials have assessed the efficacy of dexamethasone as a repeat steroid compared to betamethasone.

AIM

We aimed to determine if there were differences between the use of dexamethasone or betamethasone as repeat ACS, for women who remain at risk of preterm birth after an initial course, on maternal, infant, and childhood health outcomes.

METHODS

We performed a secondary analysis of data from the ASTEROID randomised trial, where women at risk of preterm birth were allocated to either betamethasone or dexamethasone. Infant, childhood, and maternal outcomes were compared according to whether women received a repeat dose(s) of dexamethasone or betamethasone. The primary outcome was a composite outcome of death or any neurosensory disability at age two years (corrected for prematurity). The ASTEROID trial is registered with ANZCTR, ACTRN12608000631303.

RESULTS

168 women and their infants were included, with 86 women receiving dexamethasone and 82 women receiving betamethasone as a repeat dose. Women in the two ACS groups had similar baseline characteristics. We observed little to no difference in the incidence of death or any neurosensory disability at age two years (OR 0.89, 95% CI 0.39 to 2.06, p = 0.79) or in the incidence of other infant, childhood, and maternal adverse health outcomes between women who received dexamethasone and those who received betamethasone.

CONCLUSION

Use of dexamethasone for a repeat dose(s) compared to betamethasone did not result in any differences in infant, childhood, and maternal health outcomes. These results can be used to support clinical practice guideline recommendations.

Administration of Antenatal Corticosteroids: Current State of Knowledge

The administration of a single course of corticosteroids before week 34 + 0 of gestation in cases with impending preterm birth is now standard procedure in obstetric care and firmly established in the guidelines of different countries. But despite the apparently convincing data, numerous aspects of this intervention have not yet been properly studied. It is still not clear which corticosteroid achieves the best results. There are very few studies on what constitutes an appropriate dose, circadian rhythms, the time frame in which corticosteroids are effective, and the balance between the risks and benefits of repeat administration. As the existing studies have rarely included patients before week 24 + 0 of gestation, we have very little information on the possible benefits of administering corticosteroids before this timepoint. If corticosteroids are administered antenatally after week 34 + 0 of gestation, the short-term benefit may be offset by the long-term adverse effect on psychomotor development. This present study summarizes the current state of knowledge regarding these issues.

A Comparative Study of the Respiratory Neonatal Outcomes Utilizing Dexamethasone Sodium Phosphate versus a Mixture of Betamethasone Dipropionate and Betamethasone Sodium Phosphate as an Antenatal Corticosteroid Therapy

Objective

The aim of this study is to compare the respiratory neonatal outcomes utilizing antenatal dexamethasone sodium phosphate (DSP) versus a mixture of betamethasone dipropionate and betamethasone sodium phosphate (B-DP/SP) for preterm births.

Patients and Methods

All neonatal intensive care unit (NICU) admissions for prematurity were retrospectively identified at our center in the period between September 2016 and September 2018. Pregnant women expected to give preterm birth and received steroid injections whether it is DSP or B-DP/SP were included in the study. Maternal and obstetrical data along with the corresponding respiratory neonatal outcomes were extracted and analyzed. The population was categorized according to the gestational age into extremely preterm (less than 28 weeks), very preterm (28 up to 32 weeks) and moderate or late preterm (32 up to 37 weeks) in which the repository outcomes were compared in each sub-group.

Results

A total of 650 premature neonates were included in the analysis. B-DP/SP illustrated a significant reduction in the occurrence of respiratory distress syndrome (RDS) among moderate or late preterm neonates (P = 0.003) compared to DSP. In contrast, a non-significant difference was observed between B-DP/SP and DSP regarding apnea of prematurity and transient tachypnea of the newborn. The number of neonates developed chronic lung disease has been remarkably reduced when using DSP in extremely (P = 0.038) and very (P = 0.046) preterm neonates when compared to B-DP/SP.

Conclusion

The dual acting B-DP/SP formulation could possess a significant potential in reducing RDS in moderate or late preterm neonates, while DSP groups exhibit a favorable result in the development of chronic lung disease in extreme and very preterm cohorts. Such findings emphasize the need of further clinical trials, pharmacokinetics, pharmacodynamics and cost effectiveness studies to evaluate the durability of these findings.

Antenatal corticosteroids prior to planned caesarean at term for improving neonatal outcomes

BACKGROUND

Infants born at term by elective caesarean section are more likely to develop respiratory morbidity than infants born vaginally. Prophylactic corticosteroids in singleton preterm pregnancies accelerate lung maturation and reduce the incidence of respiratory complications. It is unclear whether administration at term gestations, prior to caesarean section, improves the respiratory outcomes for these babies without causing any unnecessary morbidity to the mother or the infant.

OBJECTIVES

The objective of this review was to assess the effect of prophylactic corticosteroid administration before elective caesarean section at term, as compared to usual care (which could be placebo or no treatment), on fetal, neonatal and maternal morbidity. We also assessed the impact of the treatment on the child in later life.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov (20 January 2021) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials comparing prophylactic antenatal corticosteroid administration (betamethasone or dexamethasone) with placebo or with no treatment, given before elective caesarean section at term (at or after 37 weeks of gestation). Quasi-randomised and cluster-randomised controlled trials were also eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane Pregnancy and Childbirth methods for data collection and analysis. Two review authors independently assessed trials for inclusion, assessed risk of bias, evaluated trustworthiness (based on predefined criteria developed by Cochrane Pregnancy and Childbirth), extracted data and checked them for accuracy and assessed the certainty of the evidence using the GRADE approach. Our primary outcomes were respiratory distress syndrome (RDS), transient tachypnoea of the neonate (TTN), admission to neonatal special care for respiratory morbidity and need for mechanical ventilation. We planned to perform subgroup analyses for the primary outcomes according to gestational age at randomisation and type of corticosteroid (betamethasone or dexamethasone). We also planned to perform sensitivity analysis, including only studies at low risk of bias.

MAIN RESULTS

We included one trial in which participants were randomised to receive either betamethasone or usual care. The trial included 942 women and 942 neonates recruited from 10 UK hospitals between 1995 and 2002. This review includes only trials that met predefined criteria for trustworthiness. We removed three trials from the analysis that were included in the previous version of this review. The risk of bias was low for random sequence generation, allocation concealment and incomplete outcome data. The risk of bias for selective outcome reporting was unclear because there was no published trial protocol, and therefore it is unclear whether all the planned outcomes were reported in full. Due to a lack of blinding we judged there to be high risk of performance bias and detection bias. We downgraded the certainty of the evidence because of concerns about risk of bias and because of imprecision due to low event rates and wide 95% confidence intervals (CIs), which are consistent with possible benefit and possible harm Compared with usual care, it is uncertain if antenatal corticosteroids reduce the risk of RDS (relative risk (RR) 0.34 95% CI 0.07 to 1.65; 1 study; 942 infants) or TTN (RR 0.52, 95% CI 0.25 to 1.11; 1 study; 938 infants) because the certainty of evidence is low and the 95% CIs are consistent with possible benefit and possible harm. Antenatal corticosteroids probably reduce the risk of admission to neonatal special care for respiratory complications, compared with usual care (RR 0.45, 95% CI 0.22 to 0.90; 1 study; 942 infants; moderate-certainty evidence). The proportion of infants admitted to neonatal special care for respiratory morbidity after treatment with antenatal corticosteroids was 2.3% compared with 5.1% in the usual care group. It is uncertain if antenatal steroids have any effect on the risk of needing mechanical ventilation, compared with usual care (RR 4.07, 95% CI 0.46 to 36.27; 1 study; 942 infants; very low-certainty evidence). The effect of antenatal corticosteroids on the maternal development of postpartum infection/pyrexia in the first 72 hours is unclear due to the very low certainty of the evidence; one study (942 women) reported zero cases. The included studies did not report any data for neonatal hypoglycaemia or maternal mortality/severe mortality.

AUTHORS' CONCLUSIONS

Evidence from one randomised controlled trial suggests that prophylactic corticosteroids before elective caesarean section at term probably reduces admission to the neonatal intensive care unit for respiratory morbidity. It is uncertain if administration of antenatal corticosteroids reduces the rates of respiratory distress syndrome (RDS) or transient tachypnoea of the neonate (TTN). The overall certainty of the evidence for the primary outcomes was found to be low or very low, apart from the outcome of admission to neonatal special care (all levels) for respiratory morbidity, for which the evidence was of moderate certainty. Therefore, there is currently insufficient data to draw any firm conclusions.  More evidence is needed to investigate the effect of prophylactic antenatal corticosteroids on the incidence of recognised respiratory morbidity such as RDS. Any future trials should assess the balance between respiratory benefit and potential immediate adverse effects (e.g. hypoglycaemia) and long-term adverse effects (e.g. academic performance) for the infant. There is very limited information on maternal health outcomes to provide any assurances that corticosteroids do not pose any increased risk of harm to the mother.  Further research should consider investigating the effectiveness of antenatal steroids at different gestational ages prior to caesarean section. There are nine potentially eligible studies that are currently ongoing and could be included in future updates of this review.

How can obstetricians improve outcomes for infants born extremely preterm?

Prematurity remains a leading cause of perinatal morbidity and mortality, and also has significant implications for long-term health. Obstetricians have a key role to play in improving outcomes for infants born at extremely preterm gestations. This review explores the evidence for interventions available to obstetricians caring for women at risk of birthing at extremely preterm gestations, including antenatal corticosteroids, magnesium sulfate, tocolysis and antibiotics. It also addresses the importance of strategies to facilitate safe in-utero transfer, to maximise the chance of extremely preterm births occurring in tertiary centers, and the clinical value of strategies by which preterm birth can be predicted. The paper concludes with an appraisal of evidence for different modes of birth at extremely preterm gestations, and for delayed cord clamping.

FIGO good practice recommendations on the use of prenatal corticosteroids to improve outcomes and minimize harm in babies born preterm

For women with a singleton or a multiple pregnancy in situations where active neonatal care is appropriate, and for whom preterm birth is anticipated between 24 and 34 weeks of gestation, one course of prenatal corticosteroids should ideally be offered 18 to 72 h before preterm birth is expected to improve outcomes for the baby. However, if preterm birth is expected within 18 h, prenatal corticosteroids should still be administered. One course of corticosteroids includes two doses of betamethasone acetate/phosphate 12 mg IM 24 h apart, or two doses of dexamethasone phosphate 12 mg IM 24 h apart. In women in whom preterm birth is expected within 72 h and who have had one course of corticosteroids more than a week previously, one single additional course of prenatal corticosteroids could be given at risk of imminent delivery. Prenatal corticosteroids should not be offered routinely to women in whom late preterm birth between 34 and 36 weeks is anticipated. In addition, prenatal corticosteroids should not be given routinely before cesarean delivery at term. Neither should prenatal corticosteroids be given "just in case". Instead, prenatal steroid administration should be reserved for women for whom preterm birth is expected within no more than 7 days, based on the woman's symptoms or an accurate predictive test.

Optimized Clustering Algorithm for Comparative Analysis of Different Prenatal Corticosteroid Neurological Deficits in Premature Infants through Magnetic Reasoning Imaging (MRI)

Objective

This study aimed to explore the application of different prenatal corticosteroids in the assessment of neurological deficits and prognosis in premature infants through Magnetic Reasoning Imaging (MRI) under optimized cluster algorithm.

Methods

100 pregnant women with threatened preterm labor were retrospectively analyzed, in which 38 pregnant women with lasting threatened preterm labor (group A) were treated with multiple courses of antenatal corticosteroids (dexamethasone treatment) and 62 cases of pregnant women with threatened preterm labor (group B) were treated with single course of dexamethasone treatment. Craniocerebral MRI images based on optimal clustering algorithm were used to examine neonates. Neonatal hypoxic-ischemic encephalopathy (HIE) rate, serum neuron-specific enolase (NSE) concentration, neonatal behavioral neurological score (NBNA), respiratory distress syndrome (RDS) rate, perinatal mortality, neonatal birth weight, and maternal complications rate of two groups were compared.

Results

Compared with other traditional image segmentation algorithms, this algorithm had the best segmentation effect, the shortest running time (1.43 s), the least number of iterations (5 times), and the highest segmentation accuracy (97.98%). There was no significant difference in the HIE rate, serum NSE concentration, NBNA score, RDS score, and perinatal mortality in group A and group B (P > 0.05). Compared with group B, neonates' body weight in group A was decreased, while the maternal complication rate in group A was increased (P < 0.05).

Conclusion

MRI images based on optimized clustering algorithm can be used in the diagnosis of neonatal hypoxic-ischemic encephalopathy. There is no significant difference in the application of different antenatal corticosteroids affecting premature nerve function defect and prognosis, but multiple courses of antenatal corticosteroids can affect neonatal body mass and increased maternal complications to a certain extent; therefore, before threatened premature delivery treatment, the pros and cons of multiple courses of antenatal corticosteroids should fully be considered and in the treatment, measures should be actively taken to alleviate the side effect.

Comparison of survival of preterm newborn rabbits at 25-28 days of gestation with perinatal therapies at birth transition

Eligibility of ventilated preterm rabbit model to investigate extreme pulmonary immaturity at birth transition is unknown. By extending this model to early saccular stage of fetal lung development, we evaluated efficacy in survival, lung maturation, and underlying mechanisms of contemporary perinatal therapies. Pregnant New Zealand White rabbit does were given dexamethasone (DEX), or sham injection as control (NDEX), 48 and 24 h before delivery at gestational age (GA) of 25-28 days. At birth, newborn rabbits were anesthetized and randomly allocated to four groups receiving either surfactant or nonsurfactant for both DEX and NDEX, and mechanically ventilated within low tidal volumes. Ranges of time to maintain survival rate ≥ 50% in GA 25-28 days were 59-136, 138-259, 173-288, and 437 to ≥600 min, respectively, each across the four groups. The benefits of DEX and/or surfactant for survival were more obvious in GA 25-26 days, as judged by improved lung mechanics, lower lung injury scores, higher lung surfactant phospholipid pools, and surfactant protein mRNA expression, with DEX-surfactant combination being the most optimal for the outcome. In contrast, those of GA 27-28 days had variable but meaningful responses to the treatment. Cox regression analysis revealed GA, DEX, and surfactant being independently protective factors whereas pneumothorax was a risk factor. The extremely preterm rabbits at GA 25-26 days markedly responded to the perinatal therapies for longer survival, lung maturation and injury alleviation, and were relevant for study of preterm birth transition-associated morbidities and underlying mechanisms.NEW & NOTEWORTHY An extremely preterm rabbit model with gestational age of 25-26 (term 31) days was established by mechanical ventilation with individually adjusted tidal volume at lower ranges. The administration of antenatal glucocorticoids and/or postnatal surfactant achieved significantly longer duration to maintain 50% survival and facilitated lung maturation and protection at early saccular stage. The usefulness of this model should be validated in future investigation of perinatal and neonatal morbidity and mortality at extremely preterm birth transition.

Management of cluster headache and other trigeminal autonomic cephalalgias in pregnancy and breastfeeding

Many clinicians lack experience in managing trigeminal autonomic cephalalgias (TACs) in pregnancy and lactation. In addition to cluster headache, TACs include hemicrania continua, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing/autonomic symptoms (SUNCT/SUNA). Treating these rare, severe headache conditions often requires off-label drugs that have uncertain teratogenic potential. In the last few years, several new treatment options and safety documentation have emerged, but clinical guidelines are lacking. This narrative review aimed to provide an updated clinical guide and good clinical practice recommendations for the management of these debilitating headache disorders in pregnancy and lactation.

Chapter for antenatal steroids - Treatment drift for a potent therapy with unknown long-term safety seminars in fetal and neonatal medicine

This chapter on therapeutic drift with antenatal steroids will make the case that this pilar of treatment to improve the outcomes of preterm infants, despite multiple Randomized Control Trials (RCTs) and meta-analysis, has multiple gaps in solid clinical data to support any expanded use of Antenatal Corticosteroids (ACS). A basic problem is that agents used for ACS have never been evaluated to minimize fetal exposures. Based on the premise that all drug exposure to the fetus should be minimized and only used when necessary, ACS is a potent developmental modulator that has never been evaluated to minimize the dose and duration of fetal exposure. The use of ACS is expanding to late preterm infants where the benefit is modest, to elective C-sections, and periviable fetuses, with minimal RCT data of long-term benefit. Relevant animal experiments demonstrate that much lower doses will induce lung maturation in sheep and primates. Another area of drift in the use of ACS is based on the assumption that the old RCT data accurately predict the magnitude of benefit when ACS is used today with entirely different OB and neonatal care strategies to improve outcomes. We do not have data that demonstrate the effectiveness of ACS in very low resource environments, where most of the preterm mortality occurs. The final concern is the risk of ACS to the infant and child. Short-term risks are minimal but dysmaturation effects of ACS on multiple organ systems (lung, heart, brain, and kidney) may result in disease presentation in later life.

Prophylactic metformin after antenatal corticosteroids (PROMAC): a double blind randomized controlled trial

Background

Antenatal corticosteroids (ACS) are increasingly used to improve prematurity-related neonatal outcome. A recognized and common adverse effect from administration of antenatal corticosteroid is maternal hyperglycemia. Even normal pregnancy is characterized by relative insulin resistance and glucose intolerance. Treatment of maternal hyperglycemia after ACS might be indicated due to the higher risk of neonatal acidosis which may coincide with premature birth. Metformin is increasingly used to manage diabetes mellitus during pregnancy as it is effective and more patient friendly. There is no data on prophylactic metformin to maintain euglycemia following antenatal corticosteroids administration.

Methods

A double blind randomized trial. 103 women scheduled to receive two doses of 12-mg intramuscular dexamethasone 12-hour apart were separately randomized to take prophylactic metformin or placebo after stratification according to their gestational diabetes (GDM) status. First oral dose of allocated study drug was taken at enrolment and continued 500 mg twice daily for 72 hours if not delivered. Six-point blood sugar profiles were obtained each day (pre- and two-hour post breakfast, lunch and dinner) for up to three consecutive days. A hyperglycemic episode is defined as capillary glucose fasting/pre-meal ≥ 5.3 mmol/L or two-hour post prandial/meal ≥ 6.7 mmol/L. Primary outcome was hyperglycemic episodes on Day-1 (first six blood sugar profile points) following antenatal corticosteroids.

Results

Number of hyperglycemic episodes on the first day were not significantly different (mean ± standard deviation) 3.9 ± 1.4 (metformin) vs. 4.1 ± 1.6 (placebo) p = 0.64. Hyperglycemic episodes markedly reduced on second day in both arms to 0.9 ± 1.0 (metformin) vs. 1.2 ± 1.0 (placebo) p = 0.15 and further reduced to 0.6 ± 1.0 (metformin) vs. 0.7 ± 1.0 (placebo) p = 0.67 on third day. Hypoglycemic episodes during the 3-day study period were few and all other secondary outcomes were not significantly different.

Conclusions

In euglycemic and diet controllable gestational diabetes mellitus women, antenatal corticosteroids cause sustained maternal hyperglycemia only on Day-1. The magnitude of Day-1 hyperglycemia is generally low. Prophylactic metformin does not reduce antenatal corticosteroids’ hyperglycemic effect.

Trial registration

The trial is registered in the ISRCTN registry on May 4 2017 with trial identifier 10.1186/ISRCTN10156101.

Preventing Brain Injury in the Preterm Infant-Current Controversies and Potential Therapies

Preterm birth is associated with a high risk of morbidity and mortality including brain damage and cerebral palsy. The development of brain injury in the preterm infant may be influenced by many factors including perinatal asphyxia, infection/inflammation, chronic hypoxia and exposure to treatments such as mechanical ventilation and corticosteroids. There are currently very limited treatment options available. In clinical trials, magnesium sulfate has been associated with a small, significant reduction in the risk of cerebral palsy and gross motor dysfunction in early childhood but no effect on the combined outcome of death or disability, and longer-term follow up to date has not shown improved neurological outcomes in school-age children. Recombinant erythropoietin has shown neuroprotective potential in preclinical studies but two large randomized trials, in extremely preterm infants, of treatment started within 24 or 48 h of birth showed no effect on the risk of severe neurodevelopmental impairment or death at 2 years of age. Preclinical studies have highlighted a number of promising neuroprotective treatments, such as therapeutic hypothermia, melatonin, human amnion epithelial cells, umbilical cord blood and vitamin D supplementation, which may be useful at reducing brain damage in preterm infants. Moreover, refinements of clinical care of preterm infants have the potential to influence later neurological outcomes, including the administration of antenatal and postnatal corticosteroids and more accurate identification and targeted treatment of seizures.

Dexamethasone versus betamethasone for preterm birth: a systematic review and network meta-analysis

OBJECTIVE

This study aimed to evaluate the comparative clinical effectiveness and safety of dexamethasone vs betamethasone for preterm birth.

DATA SOURCES

The sources searched were MEDLINE, EMBASE, Cochrane Library, LILACS, ClinicalTrials.gov, and International Clinical Trials Registry Platform without language restrictions until October 2019 in addition to the reference lists of included studies. Field experts were also contacted.

STUDY ELIGIBILITY CRITERIA

Randomized or quasi-randomized controlled trials comparing any corticosteroids against each other or against placebo at any dose for preterm birth were included in the study.

METHODS

Three researchers independently selected and extracted data and assessed the risk of bias of the included studies by using Early Review Organizing Software and Covidence software. Random-effects pairwise meta-analysis and Bayesian network meta-analysis were performed. The primary outcomes were chorioamnionitis, endometritis or puerperal sepsis, neonatal death, respiratory distress syndrome, and neurodevelopmental disability.

RESULTS

A total of 45 trials (11,227 women and 11,878 infants) were included in the study. No clinical or statistical difference was found between dexamethasone and betamethasone in neonatal death (odds ratio, 1.05; 95% confidence interval, 0.62-1.84; moderate-certainty evidence), neurodevelopmental disability (odds ratio, 1.03; 95% confidence interval, 0.80-1.33; moderate-certainty evidence), intraventricular hemorrhage (odds ratio, 1.04; 95% confidence interval, 0.56-1.78); low-certainty evidence), or birthweight (+5.29 g; 95% confidence interval, -49.79 to 58.97; high-certainty evidence). There was no statistically significant difference, but a potentially clinically important effect was found between dexamethasone and betamethasone in chorioamnionitis (odds ratio, 0.70; 95% confidence interval, 0.45-1.06; moderate-certainty evidence), fetal death (odds ratio, 0.81; 95% confidence interval, 0.24-2.41; low-certainty evidence), puerperal sepsis (odds ratio, 2.04; 95% confidence interval, 0.72-6.06; low-certainty evidence), and respiratory distress syndrome (odds ratio, 1.34; 95% confidence interval, 0.96-2.11; moderate-certainty evidence). Meta-regression, subgroup, and sensitivity analyses did not reveal important changes regarding the main analysis.

CONCLUSION

Corticosteroids have proven effective for most neonatal and child-relevant outcomes compared with placebo or no treatment for women at risk of preterm birth. No important difference was found on neonatal death, neurodevelopmental disability, intraventricular hemorrhage, and birthweight between corticosteroids, and there was no statistically significant difference, but a potentially important difference was found in chorioamnionitis, fetal death, endometritis or puerperal sepsis, and respiratory distress syndrome. Further research is warranted to improve the certainty of evidence and inform health policies.

Glycemic control following two regimens of antenatal corticosteroids in mild gestational diabetes: a randomized controlled trial

PURPOSE

To compare 3 consecutive days of hyperglycemic response following antenatal dexamethasone regimens of 12-mg or 6-mg doses 12 hourly in diet-controlled gestational diabetes.

METHODS

A randomized controlled trial was carried out in a university hospital in Malaysia. Women with lifestyle-controlled gestational diabetes scheduled to receive clinically indicated antenatal corticosteroids (dexamethasone) were randomized to 12-mg 12 hourly for one day (2 × 12-mg) or 6-mg 12-hourly for two days (4 × 6-mg). 6-point (pre and 2-h postprandial) daily self-monitoring of capillary blood sugar profile for up to 3 consecutive days was started after the first dexamethasone injection. Hyperglycemia is defined as blood glucose pre-meal ≥ 5.3 or 2 h postprandial ≥ 6.7 mmol/L. The primary outcome was a number of hyperglycemic episodes in Day-1 (first 6 BSP points). A sample size of 30 per group (N = 60) was planned.

RESULTS

Median [interquartile range] hyperglycemic episodes 4 [2.5-5] vs. 4 [3-5] p = 0.3 in the first day, 3 [2-4] vs. 1 [0-3] p = 0.01 on the second day, 0 [0-1] vs. 0 [0-1] p = 0.6 on the third day and over the entire 3 trial days 7 [6-9] vs. 6 [4-8] p = 0.17 for 6-mg vs. 12-mg arms, respectively. 2/30 (7%) in each arm received an anti-glycemic agent during the 3-day trial period (capillary glucose exceeded 11 mmol/L). Mean birth weight (2.89 vs. 2.49 kg p < 0.01) and gestational age at delivery (37.7 vs. 36.6 weeks p = 0.03) were higher and median delivery blood loss (300 vs. 400 ml p = 0.02) was lower in the 12-mg arm; all other secondary outcomes were not significantly different.

CONCLUSION

In gestational diabetes, 2 × 12-mg could be preferred over 4 × 6-mg dexamethasone as hyperglycemic episodes were fewer on Day-2, fewer injections were needed and the regimen was completed sooner.

CLINICAL TRIAL REGISTRATION

http://www.isrctn.com/ISRCTN16613220 .

Antenatal corticosteroids: a reappraisal of the drug formulation and dose

We review the history of antenatal corticosteroid therapy (ACS) and present recent experimental data to demonstrate that this, one of the pillars of perinatal care, has been inadequately evaluated to minimize fetal exposure to these powerful medications. There have been concerns since 1972 that fetal exposures to ACS convey risk. However, this developmental modulator, with its multiple widespread biologic effects, has not been evaluated for drug choice, dose, or duration of treatment, despite over 30 randomized trials. The treatment used in the United States is two intramuscular doses of a mixture of 6 mg betamethasone phosphate (Beta P) and 6 mg betamethasone acetate (Beta Ac). To optimize outcomes with ACS, the goal should be to minimize fetal drug exposure. We have determined that the minimum exposure needed for fetal lung maturation in sheep, monkeys, and humans (based on published cord blood corticosteroid concentrations) is about 1 ng/ml for a 48-h continuous exposure, far lower than the concentration reached by the current dosing. Because the slowly released Beta Ac results in prolonged fetal exposure, a drug containing Beta Ac is not ideal for ACS use. IMPACT: Using sheep and monkey models, we have defined the minimum corticosteroid exposure for a fetal lung maturation. These results should generate new clinical trials of antenatal corticosteroids (ACS) at much lower fetal exposures to ACS, possibly given orally, with fewer risks for the fetus.

Antenatal corticosteroids, maternal body mass index and infant morbidity within the ASTEROID trial

BACKGROUND

Antenatal corticosteroids (ACSs) administered to women before preterm birth improve neonatal health. Proportionately more women are obese or overweight in current obstetric populations than those who were included in the original trials of ACSs, and it remains uncertain if higher doses are required for such women.

AIM

Our aim was to assess the association between maternal body mass index (BMI) and infant morbidity after the administration of ACSs.

METHODS

In the secondary analysis of the ASTEROID trial cohort, women at risk of preterm birth at <34 weeks' gestation were randomised to betamethasone or dexamethasone. Infant outcomes were compared according to whether women were of normal weight (BMI < 25 kg/m² ), overweight (BMI 25-29.9 kg/m² ) or obese (BMI ≥ 30 kg/m² ).

RESULTS

Of 982 women with a singleton pregnancy and BMI data, 519 (52.9%) were of normal size, 241 (24.5%) were overweight and 222 (22.6%) were obese. Compared with infants born to women of normal weight, there was little or no difference in respiratory distress syndrome in infants born to women who were overweight (odds ratio (OR) = 0.92, 95% confidence interval (CI) 0.57, 1.49) or obese (OR = 1.44, 95% CI 0.90, 2.31). Similarly, there were no significant differences between infants born to women in the three BMI groups for other morbidities, including bronchopulmonary dysplasia, mechanical ventilation, intraventricular haemorrhage, retinopathy of prematurity, patent ductus arteriosus, necrotising enterocolitis, perinatal death or combined serious morbidity.

CONCLUSIONS

Maternal body size is not associated with infant morbidity after ACS exposure. Dose adjustment for women with higher BMI is not required.

Maternal influences on fetal brain development: The role of nutrition, infection and stress, and the potential for intergenerational consequences

An optimal early life environment is crucial for ensuring ideal neurodevelopmental outcomes. Brain development consists of a finely tuned series of spatially and temporally constrained events, which may be affected by exposure to a sub-optimal intra-uterine environment. Evidence suggests brain development may be particularly vulnerable to factors such as maternal nutrition, infection and stress during pregnancy. In this review, we discuss how maternal factors such as these can affect brain development and outcome in offspring, and we also identify evidence which suggests that the outcome can, in many cases, be stratified by socio-economic status (SES), with individuals in lower brackets typically having a worse outcome. We consider the relevant epidemiological evidence and draw parallels to mechanisms suggested by preclinical work where appropriate. We also discuss possible transgenerational effects of these maternal factors and the potential mechanisms involved. We conclude that modifiable factors such as maternal nutrition, infection and stress are important contributors to atypical brain development and that SES also likely has a key role.

Rapamycin and dexamethasone during pregnancy prevent tuberous sclerosis complex-associated cystic kidney disease

Chronic kidney disease is the main cause of mortality in patients with tuberous sclerosis complex (TSC) disease. The mechanisms underlying TSC cystic kidney disease remain unclear, with no available interventions to prevent cyst formation. Using targeted deletion of TSC1 in nephron progenitor cells, we showed that cysts in TSC1-null embryonic kidneys originate from injured proximal tubular cells with high mTOR complex 1 activity. Injection of rapamycin to pregnant mice inhibited the mTOR pathway and tubular cell proliferation in kidneys of TSC1-null offspring. Rapamycin also prevented renal cystogenesis and prolonged the life span of TSC newborns. Gene expression analysis of proximal tubule cells identified sets of genes and pathways that were modified secondary to TSC1 deletion and rescued by rapamycin administration during nephrogenesis. Inflammation with mononuclear infiltration was observed in the cystic areas of TSC1-null kidneys. Dexamethasone administration during pregnancy decreased cyst formation by not only inhibiting the inflammatory response, but also interfering with the mTORC1 pathway. These results reveal mechanisms of cystogenesis in TSC disease and suggest interventions before birth to ameliorate cystic disease in offspring.