Antenatal corticosteroids for impending late preterm (34-36+6 weeks) deliveries-A systematic review and meta-analysis of RCTs

The World Health Organization Antenatal CorTicosteroids for Improving Outcomes in preterm Newborns (ACTION-III) Trial: study protocol for a multi-country, multi-centre, double-blind, three-arm, placebo-controlled, individually randomized trial of antenatal corticosteroids for women at high probability of late preterm birth in hospitals in low- resource countries

BACKGROUND

Preterm birth complications are the leading cause of newborn and under-5 mortality. Over 85% of all preterm births occur in the late preterm period, i.e. between 34 and < 37 weeks of gestation. Antenatal corticosteroids (ACS) prevent mortality and respiratory morbidity when administered to women at high risk of an early preterm birth, i.e. < 34 weeks' gestation. However, the benefits and risks of ACS in the late preterm period are less clear; both guidelines and practices vary between settings. Emerging evidence suggests that the benefits of ACS may be achievable at lower doses than presently used. This trial aims to determine the efficacy and safety of two ACS regimens compared to placebo, when given to women with a high probability of late preterm birth, in hospitals in low-resource countries.

METHODS

WHO ACTION III trial is a parallel-group, three-arm, individually randomized, double-blind, placebo-controlled trial of two ACS regimens: dexamethasone phosphate 4 × 6 mg q12h or betamethasone phosphate 4 × 2 mg q 12 h. The trial is being conducted across seven sites in five countries-Bangladesh, India, Kenya, Nigeria, and Pakistan. Eligible women are those with a gestational age between 34 weeks 0 days and 36 weeks 5 days, who have a high probability of preterm birth between 12 h and 7 days (up to 36 weeks 6 days gestation). The primary outcome is a composite of stillbirth or neonatal death within 72 h of birth or use of newborn respiratory support within 72 h of birth or prior to discharge from hospital, whichever is earlier. Secondary outcomes include safety and health utilization measures for both women and newborns. The sample size is 13,500 women.

DISCUSSION

This trial will evaluate the benefits and possible harms of ACS when used in women likely to have a late preterm birth. It will also evaluate a lower-dose ACS regimen based on literature from pharmacokinetic studies. The results of this trial will provide robust critical evidence on the safe and appropriate use of ACS in the late preterm period internationally.

TRIAL REGISTRATION

ISRCTN11434567 . Registered on 7 June 2021.

Late preterm antenatal steroid use and infant outcomes in a single center

OBJECTIVE

To characterize late preterm antenatal steroids (AS) use and associated neonatal outcomes in a single academic center.

STUDY DESIGN

Retrospective study of 503 singleton, mother-infant dyads delivered between 34 0/7 and 36 6/7 weeks gestation between January 1, 2016 and December 31, 2020.

RESULTS

Forty-three percent did not receive AS (No AS) prior to delivery. Among AS treated, 50% were sub-optimal dosing. No AS had higher preterm premature rupture of membranes and maternal diabetes. AS group had lower mean gestational age, birthweight, longer time from admission to delivery and longer NICU stay. There was no difference in neonatal hypoglycemia.

CONCLUSIONS

Sub-optimal AS dosing in late preterms remains high in our center. AS did not improve neonatal outcomes. Studies are needed to evaluate the impact of AS in diabetics delivering late preterm, to optimize the timing of AS dosing, and evaluate the longer term impact on late preterm infants.

The contribution of hypertensive disorders of pregnancy to late preterm and term admissions to neonatal units in the UK 2012-2020 and opportunities to avoid admission: A population-based study using the National Neonatal Research Database

OBJECTIVE

To quantify maternal hypertensive disorder of pregnancy (HDP) prevalence in late preterm and term infants admitted to neonatal units (NNU) and assess opportunities to avoid admissions.

DESIGN

A retrospective population-based study using the National Neonatal Research Database.

SETTING

England and Wales.

POPULATION

Infants born ≥34 weeks' gestation admitted to NNU between 2012 and 2020.

METHODS

Outcomes in HDP infants are compared with non-HDP infants using regression models.

MAIN OUTCOME MEASURES

Hypertensive disorder of pregnancy, primary reason for admission, clinical diagnoses and resource use.

RESULTS

16 059/136 220 (11.8%) of late preterm (34+0 to 36+6 weeks' gestation) and 14 885/284 646 (5.2%) of term (≥37 weeks' gestation) admitted infants were exposed to maternal HDP. The most common primary reasons for HDP infant admission were respiratory disease (28.3%), prematurity (22.7%) and hypoglycaemia (16.4%). HDP infants were more likely to be admitted with primary hypoglycaemia than were non-HDP infants (odds ratio [OR] 2.1, 95% confidence interval [CI] 2.0-2.2, P < 0.0001). 64.5% of HDP infants received i.v. dextrose. 35.7% received mechanical or non-invasive ventilation. 8260/30 944 (26.7%) of HDP infants received intervention for hypoglycaemia alone (i.v. dextrose) with no other major intervention (respiratory support, parenteral nutrition, central line, arterial line or blood transfusion).

CONCLUSIONS

The burden of maternal HDP on late preterm and term admissions to NNU is high, with hypoglycaemia and respiratory disease being the main drivers for admission. Over one in four were admitted solely for management of hypoglycaemia. Further research should determine whether maternal antihypertensive agent choice or postnatal pathways may reduce NNU admission.

Late Preterm Antenatal Steroid Use and Infant Outcomes in a Single Center

Objective

To characterize late preterm antenatal steroids (AS) use and associated neonatal outcomes in a single academic center.

Study Design

Retrospective study of 503 singleton, mother-infant dyads delivered between 34 0/7 to 36 6/7 weeks gestation between January 1, 2016 to December 31, 2020.

Results

43% did not receive AS (No AS) prior to delivery. Among AS treated, 50% were sub-optimal dosing. No AS had higher preterm premature rupture of membranes and maternal diabetes. AS group had lower mean gestational age and birthweight and longer time from admission to delivery and longer NICU study. There was no difference in neonatal hypoglycemia.

Conclusions

Sub-optimal AS dosing in late preterms remains high in our center. AS did not improve neonatal outcomes. Studies are needed to evaluate the impact of AS in diabetics delivering late preterm, to optimize the timing of AS dosing, and evaluate the longer term impact on late preterm infants.

Oral dextrose gel to prevent hypoglycaemia in at-risk neonates

BACKGROUND

Neonatal hypoglycaemia is a common condition that can be associated with brain injury. Current practice usually includes early identification of at-risk infants (e.g. infants of diabetic mothers; preterm, small- or large-for-gestational-age infants), and prophylactic measures are advised. However, these measures often involve use of formula milk or admission to the neonatal unit. Dextrose gel is non-invasive, inexpensive and effective for treatment of neonatal hypoglycaemia. Prophylactic dextrose gel can reduce the incidence of neonatal hypoglycaemia, thus potentially reducing separation of mother and baby and supporting breastfeeding, as well as preventing brain injury. This is an update of a previous Cochrane Review published in 2021.

OBJECTIVES

To assess the effectiveness and safety of oral dextrose gel in preventing hypoglycaemia before first hospital discharge and reducing long-term neurodevelopmental impairment in newborn infants at risk of hypoglycaemia.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and Epistemonikos in April 2023. We also searched clinical trials databases and the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing oral dextrose gel versus placebo, no intervention, or other therapies for the prevention of neonatal hypoglycaemia. We included newborn infants at risk of hypoglycaemia, including infants of mothers with diabetes (all types), high or low birthweight, and born preterm (< 37 weeks), age from birth to 24 hours, who had not yet been diagnosed with hypoglycaemia.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias. We contacted investigators to obtain additional information. We used fixed-effect meta-analyses. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included two studies conducted in high-income countries comparing oral dextrose gel versus placebo in 2548 infants at risk of neonatal hypoglycaemia. Both of these studies were included in the previous version of this review, but new follow-up data were available for both. We judged these two studies to be at low risk of bias in 13/14 domains, and that the evidence for most outcomes was of moderate certainty. Meta-analysis of the two studies showed that oral dextrose gel reduces the risk of hypoglycaemia (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.79 to 0.95; risk difference (RD) -0.06, 95% CI -0.10 to -0.02; 2548 infants; high-certainty evidence). Evidence from two studies showed that there may be little to no difference in the risk of major neurological disability at two years of age after oral dextrose gel (RR 1.00, 95% CI 0.59 to 1.68; 1554 children; low-certainty evidence). Meta-analysis of the two studies showed that oral dextrose gel probably reduces the risk of receipt of treatment for hypoglycaemia during initial hospital stay (RR 0.89, 95% CI 0.79 to 1.00; 2548 infants; moderate-certainty evidence) but probably makes little or no difference to the risk of receipt of intravenous treatment for hypoglycaemia (RR 1.01, 0.68 to 1.49; 2548 infants; moderate-certainty evidence). Oral dextrose gel may have little or no effect on the risk of separation from the mother for treatment of hypoglycaemia (RR 1.12, 95% CI 0.81 to 1.55; two studies, 2548 infants; low-certainty evidence). There is probably little or no difference in the risk of adverse effects in infants who receive oral dextrose gel compared to placebo gel (RR 1.22, 95% CI 0.64 to 2.33; two studies, 2510 infants; moderate-certainty evidence), but there are no studies comparing oral dextrose with other comparators such as no intervention or other therapies. No data were available on exclusive breastfeeding after discharge.

AUTHORS' CONCLUSIONS

Prophylactic oral dextrose gel reduces the risk of neonatal hypoglycaemia in at-risk infants and probably reduces the risk of treatment for hypoglycaemia without adverse effects. It may make little to no difference to the risk of major neurological disability at two years, but the confidence intervals include the possibility of substantial benefit or harm. Evidence at six to seven years is limited to a single small study. In view of its limited short-term benefits, prophylactic oral dextrose gel should not be incorporated into routine practice until additional information is available about the balance of risks and harms for later neurological disability. Additional large follow-up studies at two years of age or older are required. Future research should also be undertaken in other high-income countries, low- and middle-income countries, preterm infants, using other dextrose gel preparations, and using comparators other than placebo gel. There are three studies awaiting classification and one ongoing study which may alter the conclusions of the review when published.

Antenatal Corticosteroid Treatment During the Late-Preterm Period and Neonatal Outcomes for Twin Pregnancies

Importance

Antenatal corticosteroid treatment of individuals with singletons at risk for delivery during the late-preterm period has been academically recommended. However, the evidence on the use of antenatal corticosteroid treatment for twins at risk for delivery during the late-preterm period is still lacking.

Objective

To evaluate whether antenatal corticosteroid treatment during the late-preterm period in twin pregnancies was associated with a lower risk of newborn morbidity.

Design, Setting, and Participants

This retrospective cohort study of twin pregnancies delivered from February 1, 2013, to September 30, 2020, in a university-affiliated hospital in China included 1974 individuals with twin pregnancies who were at risk for late preterm birth (34 weeks and 0 days to 36 weeks and 6 days of gestation). Data were analyzed from June 30 to July 13, 2023.

Exposures

Antenatal corticosteroid treatment during the late-preterm period.

Main Outcomes and Measures

The primary outcome measure was composite neonatal respiratory morbidity, defined as at least 1 of the following postnatal occurrences in at least 1 neonate of the twins: respiratory distress syndrome, mechanical ventilation, surfactant administration, transferred with respiratory complications, or neonatal death. Propensity score overlap weighting was used to analyze the association between antenatal corticosteroid treatment and the risk of neonatal outcomes.

Results

The study population consisted of 1974 individuals with twin pregnancies, including 303 (15.3%; mean [SD] maternal age, 30.8 [4.2] years) who received antenatal corticosteroid treatment and 1671 (84.7%; mean [SD] maternal age, 31.2 [4.0] years) who did not receive antenatal corticosteroid treatment. The propensity score overlap weighting showed no significant differences between the antenatal corticosteroid treatment group and the no-antenatal corticosteroid treatment group in the risk of neonatal primary outcome (29 of 303 [9.6%] vs 41 of 1671 [2.5%]; weighted odds ratio, 1.27 [95% CI, 0.60-2.76]). None of the subgroup interaction tests were significant for the neonatal primary outcome in terms of gestational age at delivery, year of delivery, chorionicity, at least 1 infant small for gestational age, intertwin growth discordance, and infant sex, and neither was the sensitivity analysis of using propensity score matching and a different administration-to-birth interval and treating twin infants as individuals.

Conclusions and Relevance

This cohort study found insufficient evidence that antenatal corticosteroid treatment during the late-preterm period in twin pregnancies could be associated with a lower risk of newborn morbidity. This new finding can provide a reference for clinical practice.

Antenatal corticosteroids in specific groups at risk of preterm birth: a systematic review

OBJECTIVE

This study aimed to synthesise available evidence on the efficacy of antenatal corticosteroid (ACS) therapy among women at risk of imminent preterm birth with pregestational/gestational diabetes, chorioamnionitis or fetal growth restriction (FGR), or planned caesarean section (CS) in the late preterm period.

METHODS

A systematic search of MEDLINE, EMBASE, CINAHL, Cochrane Library, Web of Science and Global Index Medicus was conducted for all comparative randomised or non-randomised interventional studies in the four subpopulations on 6 June 2021. Risk of Bias Assessment tool for Non-randomised Studies and the Cochrane Risk of Bias tool were used to assess the risk of bias. Grading of Recommendations Assessment, Development and Evaluations tool assessed the certainty of evidence.

RESULTS

Thirty-two studies involving 5018 pregnant women and 10 819 neonates were included. Data on women with diabetes were limited, and evidence on women undergoing planned CS was inconclusive. ACS use was associated with possibly reduced odds of neonatal death (pooled OR: 0.51; 95% CI: 0.31 to 0.85, low certainty), intraventricular haemorrhage (pooled OR: 0.41; 95% CI: 0.23 to 0.72, low certainty) and respiratory distress syndrome (pooled OR: 0.59; 95% CI: 0.45 to 0.77, low certainty) in women with chorioamnionitis. Among women with FGR, the rates of surfactant use (pooled OR: 0.38; 95% CI: 0.23 to 0.62, moderate certainty), mechanical ventilation (pooled OR: 0.42; 95% CI: 0.26 to 0.66, moderate certainty) and oxygen therapy (pooled OR: 0.48; 95% CI: 0.30 to 0.77, moderate certainty) were probably reduced; however, the rate of hypoglycaemia probably increased (pooled OR: 2.06; 95% CI: 1.27 to 3.32, moderate certainty).

CONCLUSIONS

There is a paucity of evidence on ACS for women who have diabetes. ACS therapy may have benefits in women with chorioamnionitis and is probably beneficial in FGR. There is limited direct trial evidence on ACS efficacy in women undergoing planned CS in the late preterm period, though the totality of evidence suggests it is probably beneficial.

PROSPERO REGISTRATION NUMBER

CRD42021267816.

Neonatal hypoglycemia following antenatal corticosteroid treatment prior to elective cesarean delivery during the early term period: a meta-analysis

OBJECTIVE

The necessity of administering antenatal corticosteroids in early-term neonates delivered by planned cesarean delivery remains arbitrary as their observed benefit addresses a few cases that may need pulmonary resuscitation. However, to date, whether the use of antenatal corticosteroids in the preterm period is associated with neonatal hypoglycemia, which is the most prominent neonatal side effect during this period, remains unknown. This study aimed to determine the effect of antenatal corticosteroids administered during the early term period on neonatal hypoglycemia rates.

DATA SOURCES

The databases of Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials, and Google Scholar were used.

STUDY ELIGIBILITY CRITERIA

Published clinical trials and observational studies were considered eligible.

METHODS

A modified data form that was based on the Cochrane data collection form for intervention reviews for randomized controlled trials and nonrandomized controlled trials was used. Meta-analysis was performed using RStudio (RStudio, Inc, Boston, MA). The quality of included studies was assessed with the Risk Of Bias In Non-randomized Studies of Interventions tool. Trial sequential analysis was performed to evaluate the sample size.

RESULTS

A total of 6 studies of moderate risk of bias were included in this systematic review consisting of 1273 parturients, of whom 537 received corticosteroids. The risk of neonatal hypoglycemia did not increase with the use of antenatal corticosteroids before early-term elective cesarean delivery (odds ratio, 1.80; 95% confidence interval, 0.45-7.25). Similarly, the risk of admission to the neonatal intensive care unit for respiratory distress syndrome or transient tachypnoea of the newborn was not affected by the use of corticosteroids (odds ratio, 0.61; 95% confidence interval, 0.19-1.99).

CONCLUSION

The use of antenatal corticosteroids did not seem to increase the risk of neonatal hypoglycemia. Given the quality and sample size of included studies, the effect size cannot be accounted for as definitive and cannot be directly applied in clinical practice. However, the provided information can be used as a guide for women participating in future trials.

Booster course of antenatal corticosteroids after preterm prelabor rupture of membranes: a double-blind randomized trial

BACKGROUND

Preterm prelabor rupture of membranes is a leading cause of preterm birth and is responsible for 18% to 20% of perinatal deaths in the United States. An initial course of antenatal corticosteroids has been shown to reduce morbidity and mortality in patients with preterm prelabor rupture of membranes. For patients who remain undelivered for 7 days or more after the initial course of antenatal corticosteroids, it is uncertain whether a booster course of antenatal corticosteroids reduces neonatal morbidity or increases the infection risk. The American College of Obstetricians and Gynecologists has concluded that the current evidence is insufficient to make a recommendation.

OBJECTIVE

This study aimed to evaluate if a single booster course of antenatal corticosteroids improves neonatal outcomes after preterm prelabor rupture of membranes.

STUDY DESIGN

We conducted a multicenter, placebo-controlled randomized clinical trial. The inclusion criteria were preterm prelabor rupture of membranes, gestational age of 24.0 to 32.9 weeks, singleton, initial antenatal corticosteroid course administered at least 7 days before randomization, and planned expectant management. Consenting patients were randomized in gestational age blocks to either receive booster antenatal corticosteroids (12 mg betamethasone every 24 hours for 2 days) or a saline placebo. The primary outcome was composite neonatal morbidity or death. A sample size of 194 patients was calculated to yield 80% power at P<.05 to detect a reduction in primary outcome from 60% in placebo group to 40% in antenatal corticosteroids group.

RESULTS

From April 2016 through August 2022, 194 patients consented and were randomized (47% of 411 eligible patients). Intent-to-treat analysis was performed on 192 patients (2 placebo patients left hospital, outcomes unknown). The groups had similar baseline characteristics. The primary outcome occurred in 64% of patients who received booster antenatal corticosteroids vs in 66% of patients who received the placebo (odds ratio, 0.82; 95% confidence interval, 0.43-1.57; gestational age-stratified Cochran-Mantel-Haenszel test). Individual components of the primary outcome and secondary neonatal and maternal outcomes were not significantly different between the antenatal corticosteroids and placebo groups. Specifically, chorioamnionitis (22% vs 20%), postpartum endometritis (1% vs 2%), wound infections (2% vs 0%), and proven neonatal sepsis (5% vs 3%) were not different between the groups.

CONCLUSION

A booster course of antenatal corticosteroids at least 7 days after the first antenatal corticosteroids course in patients with preterm prelabor rupture of membranes did not improve neonatal morbidity or any other outcome in this adequately-powered, double-blind randomized clinical trial. Booster antenatal corticosteroids did not increase maternal or neonatal infection.

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.

Antenatal Corticosteroid Exposure is Associated with Childhood Mental Disorders in Late Preterm and Term Infants

OBJECTIVES

To study the association between antenatal corticosteroids treatment and childhood mental disorders in infants born at different gestational ages, and to investigate the effect of different administration timing.

STUDY DESIGN

This population-based cohort study used data from the Taiwan National Health Insurance Research Database. All singleton live births born between 2004 and 2010 were enrolled and followed up for at least 6 years. The primary outcome was any childhood mental disorder. Secondary outcomes included 7 specific subgroups of mental disorders.

RESULTS

A total of 1 163 443 singleton infants were included in the analysis, and 16 847 (1.45%) infants were exposed to antenatal corticosteroid treatment. Children exposed to antenatal corticosteroids were found to have a higher risk of developing childhood mental disorders in the entire cohort (hazard ratio [HR], 1.13; 95% CI, 1.08-1.18), the term group (HR, 1.11; 95% CI, 1.05-1.16), and the late-preterm group (HR, 1.15; 95% CI, 1.06-1.25). The administration of corticosteroids in the early stage of pregnancy (<28 weeks of gestation) significantly increased the risk of childhood mental disorders (HR, 1.22; 95% CI, 1.14-1.31).

CONCLUSIONS

Exposure to antenatal corticosteroid treatment increases the cumulative risk of childhood mental disorders and attention deficit hyperactivity disorders, both in term and late preterm infants. The administration of corticosteroids in the early stage of pregnancy tends to increase the risk of mental disorders.

Low-dose antenatal betamethasone treatment achieves preterm lung maturation equivalent to that of the World Health Organization dexamethasone regimen but with reduced endocrine disruption in a sheep model of pregnancy

BACKGROUND

The intramuscular administration of antenatal steroids to women at risk of preterm delivery achieves high maternal and fetal plasma steroid concentrations, which are associated with adverse effects and may reduce treatment efficacy. We have demonstrated that antenatal steroid efficacy is independent of peak maternofetal steroid levels once exposure is maintained above a low threshold.

OBJECTIVE

This study aimed to test, using a sheep model of pregnancy, whether the low-dose antenatal steroid regimen proposed as part of the Antenatal Corticosteroids for Improving Outcomes in Preterm Newborns trial would achieve preterm lung maturation equivalent to that of the existing World Health Organization dexamethasone treatment regimen, but with reduced risk of adverse outcomes.

STUDY DESIGN

Following ethical review and approval, date-mated ewes with single fetuses received intramuscular injections of either (1) four 6-mg maternal intramuscular injections of dexamethasone phosphate every 12 hours (n=22), (2) 4 2-mg maternal intramuscular injections of betamethasone phosphate every 12 hours (n=21), or (3) 4 2-mL maternal intramuscular injections of saline every 12 hours (n=16). Of note, 48 hours after first injection, (124±1 day), lambs were delivered, ventilated for 30 minutes, and euthanized for sampling. Arterial blood gas, respiratory, hematological, and biochemical data were analyzed for between-group differences with analysis of variance according to distribution and variance, with P<.05 taken as significant.

RESULTS

After 30 minutes of ventilation, lambs from both steroid-treated groups had significant and equivalent improvements in lung function relative to saline control (P<.05). There was no significant difference in arterial blood pH, pO₂, pCO₂, lung compliance, ventilator efficiency index, or lung volume at necropsy with a static pressure of 40 cmH₂O. The messenger RNA expression of surfactant protein (Sp)a, Spb, Spc, Spd, aquaporin (Aqp)1, Aqp5, and sodium channel epithelial 1 subunit beta (Scnn1b) was equivalent between both steroid groups. Maternal and fetal plasma neutrophil, glucose, and fetal plasma C-peptide levels were significantly elevated in the dexamethasone group, relative to the betamethasone group. Fetal plasma insulin-like growth factor 1 was significantly reduced in the dexamethasone group compared with the betamethasone group (P<0.05). Fetal adrenocorticotropic hormone (r=0.53), maternal glucose value (r=-0.52), and fetal glucose values (r=-0.42) were correlated with maternal weight in the betamethasone group (P<.05), whereas fetal pCO₂ and pO₂ were not correlated. There was no significant difference between male and female lamb outcomes in any groups for any of the items evaluated.

CONCLUSION

This study reported that in preterm lambs, a low-dose treatment regimen of 8 mg betamethasone achieves lung maturation equivalent to that of a 24-mg dexamethasone-based regimen, but with smaller perturbations to the maternofetal hypothalamic-pituitary-adrenal axis. These data suggested that given steroid pharmacokinetic differences between sheep and humans, a betamethasone dose of 2 mg may remain above the minimum dose necessary for robust maturation of the preterm lung. Maternal weight-adjusted betamethasone doses might also be a key to reducing perturbations to the maternofetal hypothalamic-pituitary-adrenal axis.

Associations Between Maternal Antenatal Corticosteroid Treatment and Psychological Developmental and Neurosensory Disorders in Children

IMPORTANCE

Corticosteroids administered to women at risk of imminent preterm birth is one of the most effective ways to improve the prognosis of infants born preterm. Scant data about long-term neurodevelopmental and neurosensory outcomes among the treatment-exposed children are mixed, suggesting that not all domains of neurodevelopmental and neurosensory function may be equally affected. Moreover, the long-term outcomes may vary according to whether the treatment-exposed children are being born preterm (<37 weeks and 0 days) or term (≥37 weeks and 0 days).

OBJECTIVES

To study whether antenatal corticosteroid treatment is associated with psychological developmental and neurosensory disorders in children born term and preterm and whether the associations persist in a sibling-comparison design.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective register-linkage study comprised all singleton live births in Finland between January 1, 2006, and December 31, 2017, followed up until December 31, 2018, as well as a sibling comparison among term sibling pairs. Data were analyzed from March 21, 2021, to July 7, 2022.

EXPOSURES

Antenatal corticosteroid treatment.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards regression models were used to estimate the associations between antenatal corticosteroid treatment and physician-diagnosed specific developmental disorders of speech and language, scholastic skills, and motor function; pervasive developmental disorder; other or unspecified psychological developmental disorder; disorders of vison and hearing; epilepsy; and cerebral palsy.

RESULTS

The study population comprised 670 097 singleton children (342 562 boys [51.1%]) followed up for a median of 5.8 years (IQR, 3.1-8.7 years). Of the 14 868 treatment-exposed children (2.2%; 53.9% boys), 6730 (45.3%) were born term, and 8138 (54.7%) were born preterm, and of the 655 229 nonexposed children (97.8%; 51.1% boys), 634 757 (96.9%) were born term, and 20 472 (3.1%) were born preterm. Of the 241 621 eligible maternal sibling pairs born term, 4128 (1.7%) were discordant for treatment exposure. Compared with nonexposure in the entire population, treatment exposure was significantly associated with higher adjusted hazard ratios (aHRs) for specific developmental disorders of speech and language (aHR, 1.38 [95% CI, 1.27-1.50]; P < .001), specific developmental disorders of scholastic skills (aHR, 1.32 [95% CI, 1.13-1.54]; P = .004), specific developmental disorder of motor function (aHR, 1.32 [95% CI, 1.18-1.49]; P < .001), pervasive developmental disorder (aHR, 1.35 [95% CI, 1.17-1.56]; P < .001), other or unspecified disorder of psychological development (aHR, 1.88 [95% CI, 1.58-2.25]; P < .001), and vision or hearing loss (aHR, 1.22 [95% CI, 1.04-1.43]; P = .02). Compared with nonexposure in the term-born group, treatment exposure was significantly associated with higher aHRs for specific developmental disorders of speech and language (aHR, 1.47 [95% CI, 1.31-1.66]; P < .001), specific developmental disorders of scholastic skills (aHR, 1.28 [95% CI, 1.01-1.63]; P = .04), specific developmental disorder of motor function (aHR, 1.38 [95% CI, 1.12-1.70]; P < .001), pervasive developmental disorder (aHR, 1.42 [95% CI, 1.16-1.75]; P < .001), other or unspecified disorder of psychological development (aHR, 1.92 [95% CI, 1.51-2.43]; P < .001), epilepsy (aHR, 1.57 [95% CI, 1.22-2.01]; P < .001), and cerebral palsy (aHR, 2.18 [95% CI, 1.47-3.23]; P < .001). The hazard for any psychological developmental and neurosensory disorder was significantly higher for the treatment-exposed sibling compared with the nonexposed cosibling (absolute difference, 1.2% [95% CI, 0.03%-2.4%]; P < .001; aHR, 1.22 [95% CI, 1.04-1.42]; P = .01). Antenatal corticosteroids were not associated with either significant benefit or risk in the preterm group.

CONCLUSIONS AND RELEVANCE

This study suggests that the possible long-term psychological developmental and neurosensory harms warrant careful consideration of risks and benefits when deciding on maternal antenatal corticosteroid treatment.

The use of antenatal corticosteroids for fetal maturation: clinical practice guideline by the WAPM-World Association of Perinatal Medicine and the PMF-Perinatal Medicine foundation

This practice guideline follows the mission of the World Association of Perinatal Medicine in collaboration with the Perinatal Medicine Foundation, bringing together groups and individuals throughout the world, with the goal of improving the use of antenatal corticosteroids (ACS) for fetal maturation. In fact, this document provides further guidance for healthcare practitioners on the appropriate use of ACS with the aim to increase the timely administration and avoid unnecessary or excessive use. Therefore, it is not intended to establish a legal standard of care. This document is based on consensus among perinatal experts throughout the world and serves as a guideline for use in clinical practice.

US Incidence of Late-Preterm Steroid Use and Associated Neonatal Respiratory Morbidity After Publication of the Antenatal Late Preterm Steroids Trial, 2015-2017

IMPORTANCE

The Antenatal Late Preterm Steroids (ALPS) trial demonstrated a 20% reduction in the risk of respiratory complications in neonates at risk for a late-preterm birth who were exposed to antenatal corticosteroids compared with those who were not.

OBJECTIVE

To assess whether new evidence of steroid administration for neonatal respiratory benefit in the late-preterm period is associated with changes in obstetric practice and the use of assisted ventilation for the neonate after delivery.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study of US births from February 1, 2015, to October 31, 2017, as ascertained from US natality data, included live-born, singleton neonates born between 34 and 36 completed weeks of gestation to people without pregestational diabetes. An interrupted time series analysis using Poisson regression models was conducted. Data were analyzed from July 11, 2022, to November 9, 2022.

EXPOSURES

Public dissemination of the ALPS trial results, which occurred during a 9-month period from February 1, 2016 (first published online), to October 31, 2016 (time of the last major professional society's guideline update in the months after the trial's publication).

MAIN OUTCOMES AND MEASURES

Steroid use, any assisted ventilation use, and assisted ventilation use for more than 6 hours immediately after the dissemination period.

RESULTS

A total of 707 862 births were included, divided among the 12-month predissemination period (n = 250 643), dissemination period (n = 195 736), and 12-month postdissemination period (n = 261 493). Most births were at 36 weeks of gestation (53.9% in the predissemination and postdissemination period; P = .10). Small but significant differences were found between the predissemination and postdissemination period cohorts: there were more individuals 35 years or older (19.5% vs 17.9%), fewer White individuals (67.8% vs 69.8%), and more publicly insured individuals (50.5% vs 50.1%) in the postdissemination period compared with the predissemination period, respectively (P < .001 for all). Compared with what rates were expected based on the predissemination trends, the adjusted rate of steroid use increased from 5.0% to 11.7% (adjusted incidence rate ratio [IRR], 2.34; 95% CI, 2.13-2.57), and assisted ventilation use decreased from 8.9% to 8.2% (adjusted IRR, 0.91; 95% CI, 0.85-0.98) after the dissemination period. No change was observed in assisted ventilation use for more than 6 hours (adjusted IRR, 0.98; 95% CI, 0.87-1.10).

CONCLUSIONS AND RELEVANCE

These findings suggest that there was an immediate change in practice of administering antenatal steroids and a reduction in neonatal morbidity among late-preterm births associated with the dissemination of the ALPS trial, suggesting that this evidence may be translating into a reduction in immediate respiratory morbidity outside the context of a clinical trial.

Antenatal Corticosteroids to Asian Women Prior to Elective Cesarean Section at Early Term and Effects on Neonatal Respiratory Outcomes

This exploratory study aimed to evaluate the effects of antenatal corticosteroids in singleton pregnancies of Asian women prior to elective cesarean section (CS) at early term on neonatal respiratory outcomes.

METHODS

This is a pilot and pragmatic randomized trial conducted at a university hospital in Malaysia. Women with singleton pregnancies planned for elective CS between 37+0 and 38+6 weeks gestation were randomly allocated into the intervention group, where they received two doses of IM dexamethasone 12 mg of 12 h apart, 24 h prior to surgery OR into the standard care, control group, and both groups received the normal routine antenatal care. The primary outcome measures were neonatal respiratory illnesses, NICU admission and length of stay.

RESULTS

A total of 189 patients were recruited, 93 women in the intervention group and 96 as controls. Between the steroid and control groups, the mean gestation at CS was similar, 266.1 ± 3.2 days (38 weeks) vs. 265.8 ± 4.0 days (37+6 weeks), p = 0.53. The mean birthweight of infants was 3.06 ± 0.41 kg vs. 3.04 ± 0.37 kg, p = 0.71. Infants with respiratory morbidities were primarily due to transient tachypnea of newborn (9.7% vs. 6.3%), and congenital pneumonia (1.1% vs. 3.1%) but none had respiratory distress syndrome. Only four infants required NICU admission (2.2% vs. 3.1%, p = 0.63). Their average length of stay was not statistically different; 3.5 ± 2.1 days vs. 5.7 ± 1.5 days, p = 0.27.

CONCLUSIONS

Elective CS at early term before 39 weeks was associated with a modest overall incidence of neonatal respiratory illness (10.1%) in this Asian population. Antenatal dexamethasone did not diminish infants needing respiratory support, NICU admission and length of stay.

The impact of the Antenatal Late Preterm Steroids trial on the administration of antenatal corticosteroids

BACKGROUND

In 2016 the Antenatal Late Preterm Steroids study was published, demonstrating that antenatal corticosteroid therapy given to women at risk of late preterm delivery reduces respiratory morbidity in infants. However, the administration of antenatal corticosteroid therapy in late-preterm infants remains controversial. Late-preterm infants do not suffer from the same rates of morbidity as early-preterm infants, and the short-term benefits of antenatal corticosteroid therapy are less pronounced; consequently, the risk of possible harm is more difficult to balance.

OBJECTIVE

This study aimed to evaluate the association between the publication of the Antenatal Late Preterm Steroids study or the subsequent changes in guidelines and the rates of antenatal corticosteroid therapy administration in late-preterm infants in the United States.

STUDY DESIGN

Data analyzed were publicly available US birth certificate data from January 1, 2016 to December 31, 2018. An interrupted time series design was used to analyze the association between publication of the Antenatal Late Preterm Steroids study and changes in monthly rates of antenatal corticosteroid administration in late preterm gestation (34+0 to 36+6 weeks). Births at 28+0 to 31+6 weeks' gestation were used as a control. Antenatal corticosteroid therapy administration in women with births at 32+0 to 34+6 weeks was explored to analyze whether the intervention influenced antenatal corticosteroid therapy administration in women in the subgroup approaching 34 weeks' gestation. Antenatal corticosteroid therapy administration in women with term births (>37 weeks' gestation) was analyzed to explore if the intervention influenced the number of term babies exposed to antenatal corticosteroid therapy. Our regression model allowed analysis of both step and slope changes. February 2016 was chosen as the intervention period.

RESULTS

Our sample size was 18,031,950 total births. Of these, 1,056,047 were births at 34+0 to 36+6 weeks' gestation, 123,788 at 28+0 to 31+6 weeks, 153,708 at 32 to 33 weeks, and 16,602,699 were term births. There were 95,708 births at <28 weeks' gestation. There was a statistically significant increase in antenatal corticosteroid therapy administration rates in late preterm births following the online publication of the Antenatal Late Preterm Steroids study (adjusted incidence rate ratio, 1.48; 95% confidence interval, 1.36-1.61; P=.00). A significant increase in antenatal corticosteroid therapy administration rates was also seen in full-term births following the online publication of the Antenatal Late Preterm Steroids study. No significant changes were seen in antenatal corticosteroid administration rates in gestational age groups of 32+0 to 33+6 weeks or 28+0 to 31+6 weeks.

CONCLUSION

Online publication of the Antenatal Late Preterm Steroids study was associated with an immediate and sustained increase in the rates of antenatal corticosteroid therapy administration in late preterm births across the United States, demonstrating a swift and successful implementation of the Antenatal Late Preterm Steroids study guidance into clinical practice. However, there is an unnecessary increase in full-term infants receiving antenatal corticosteroid therapy. Given that the long-term consequences of antenatal corticosteroid therapy are yet to be elucidated, efforts should be made to minimize the number of infants unnecessarily exposed to antenatal corticosteroid therapy.

Effect of Antenatal Dexamethasone in Late Preterm Period on Neonatal Hypoglycemia: A Prospective Cohort Study from a Developing Country

OBJECTIVES

This study compared the risk of hypoglycemia within 72 h of life in infants with and without exposure to antenatal dexamethasone in the late preterm period (34-366/7 week's gestational age).

METHODS

This prospective cohort study was conducted in a tertiary care neonatal unit of Eastern India from May 2021 to November 2021. Babies in the exposed group received at least one dose of antenatal dexamethasone in the late preterm period between 7 days before delivery and birth. 'Complete course' of antenatal steroid was defined as four doses of injection dexamethasone at 12 h intervals and <4 doses were considered as 'Partial course'. Primary outcome was incidence of hypoglycemia within 72 h of life, defined as whole blood glucose <45 mg/dl.

RESULTS

Total 298 infants (98 in control, 134 in partial and 66 in complete group) were assessed for final outcome. No significant difference in outcomes were seen in the exposed group compared to unexposed group. However, incidence of hypoglycemia within 72 h (complete vs. partial p= 0.008, complete vs. control p=0.005) and 12 h of life (complete vs. partial p=0.013, complete vs. control p=0.013) was significantly less in complete steroid group. Logistic regression analysis revealed complete course of antenatal corticosteroid significantly decreased the risk of hypoglycemia [adjusted odds ratio, 95% confidence interval (CI) 0.15 (0.03-0.69), p=0.015]. Number needed to be exposed for one additional benefit was 7 (95% CI, 6.35-22.14).

CONCLUSION

Complete course of dexamethasone administered to mothers at risk of late preterm delivery reduces risk of neonatal hypoglycemia within 72 h of life.

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.