Antenatal corticosteroids after 34 weeks' gestation: Do we have the evidence?

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.

Impact on neonatal morbidities after a change in policy to administer antenatal corticosteroids to mothers at risk for late preterm delivery

OBJECTIVES

Antenatal corticosteroids (ACS) administered to mothers at risk for preterm delivery before 34 weeks has been standard care to improve neonatal outcomes. After introducing a new obstetric policy based on updated recommendations advising the administration of ACS to pregnant women at risk for late preterm (LPT) delivery (34-36 6/7 weeks), we set out to determine the short-term clinical impact on those LPT neonates.

METHODS

Retrospective chart review of LPT neonates delivered at NYU Langone Medical Center both one year before and after the policy went into place. We excluded subjects born to mothers with pre-gestational diabetes, multiple gestations, and those with congenital/genetic abnormalities. We also excluded subjects whose mothers already received ACS previously in pregnancy. Subjects were divided into pre-policy and post-policy groups. Neonatal and maternal data were compared for both groups.

RESULTS

388 subjects; 180 in the pre-policy and 208 in the post-policy group. This policy change resulted in a significant increase in ACS administration to mothers who delivered LPT neonates (67.3 vs. 20.6%, p<0.001). In turn, there was a significant reduction in LPT neonatal intensive care unit (NICU) admissions (44.2 vs. 54.4%, p=0.04) and need for respiratory support (27.9 vs. 42.8%, p<0.01). However, we also found an increased incidence of hypoglycemia (49.5 vs. 28.3%, p<0.001).

CONCLUSIONS

This LPT ACS policy appears effective in reducing the need for LPT NICU level care overall. However, clinicians must be attentive to monitor for adverse effects like hypoglycemia, and there remains a need for better understanding of potential long-term impacts.

Prenatal Betamethasone Exposure and its Impact on Pediatric Type 1 Diabetes Mellitus: A Preliminary Study in a Spanish Cohort

BACKGROUND

Betamethasone, a glucocorticoid used to induce lung maturation when there is a risk of preterm delivery, can affect the immune system maturation and type 1 diabetes (T1D) incidence in the progeny. It has been described that prenatal betamethasone protects offspring from experimental T1D development. The main aim of this study was to evaluate the possible association between betamethasone prenatal exposure and T1D in humans. Research Design and Methods. A retrospective case-control study with a total of 945 children, including 471 patients with T1D and 474 healthy siblings, was performed. Participants were volunteers from the Germans Trias i Pujol Hospital and DiabetesCero Foundation. Parents of children enrolled in the study completed a questionnaire that included questions about weeks of gestation, preterm delivery risk, weight at birth, and prenatal betamethasone exposure of their children. Multiple logistic regression was used to detect the association between betamethasone exposure and T1D.

RESULTS

We compared T1D prevalence between subjects prenatally exposed or unexposed to betamethasone. The percent of children with T1D in the exposed group was 37.5% (21 of 56), and in the unexposed group was 49.52% (410 of 828) (p = 0.139). The percentage of betamethasone-treated subjects with T1D in the preterm group (18.05%, 13 of 72) was significantly higher than that found in the control group (12.5%, 9 of 72) (p = 0.003). The odds ratio for T1D associated with betamethasone in the univariate logistic regression was 0.59 (95% confidence interval, 0.33; 1.03 [p = 0.062]) and in the multivariate logistic regression was 0.83 (95% confidence interval, 0.45; 1.52 [p = 0.389]).

CONCLUSIONS

The results demonstrate that the prenatal exposure to betamethasone does not increase T1D susceptibility, and may even be associated with a trend towards decreased risk of developing the disease. These preliminary findings require further prospective studies with clinical data to confirm betamethasone exposure effect on T1D risk.

The effects of betamethasone on clinical outcome of the late preterm neonates born between 34 and 36 weeks of gestation

Background

Prenatal corticosteroid administration in preterm labor is one of the most important treatments available to improve neonatal outcomes; however, its beneficial effects on late preterm infants (after the 34th week of gestation) remained unknown. We aimed to assess the effects of betamethasone on the clinical condition of the late preterm infants born between 34 and 36 weeks of gestation.

Methods

This retrospective cohort study was performed on 100 consecutive infants born between 34 and 36 weeks of gestation and received betamethasone before delivery as the cases and 100 neonates with the same delivery conditions but without receiving betamethasone. All neonates were followed up within hospitalization to assess the neonatal outcome.

Results

The neonates receiving betamethasone suffered more from respiratory distress syndrome (49% versus 31%, p = 0.008, RR = 1.59 95% CI (1.12–2.27)) and requiring more respiratory support (71% versus 50%, p = 0.002, RR = 1.43 95% CI (1.13–1.80)) as compared to the control group. There was no difference between the two groups in other neonatal adverse events or death.

Conclusion

the use of betamethasone in the late preterm period (after 34 weeks of gestation) has no beneficial effects on lung maturity or preventing neonatal adverse outcomes, even may lead to increase the risk for RDS and requiring respiratory support.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04246-x.

Antenatal corticosteroids affecting enteral feeding and growth of preterm infants: A retrospective cohort study

BACKGROUND

Treatment of antenatal corticosteroids (ACSs) to women at risk of preterm labor can decrease neonatal mortality and morbidity. However, effect of ACS exposure on enteral feeding and body growth of preterm infants remains elusive.

METHODS

This retrospective study collected information of eligible singleton infants born between 22⁺⁰ and 36⁺⁶ weeks' gestation from 2017 to 2019. Logistic regression and multivariate linear regression were adopted to examine the associations of the ACS exposure with various outcomes of enteral feeding and growth considering potential confounders. Stratified analysis was performed based on gestational age (GA) (<34 vs ≥34 weeks).

RESULTS

Of the 1694 preterm infants included, 1222 (72.1%) were exposed to ACSs. Infants with ACS exposure had a higher incidence of feeding intolerance (odds ratio 1.51; 95% CI, 1.05 to 2.20; P = .03), slower advancement of enteral feeding (β coefficient -0.86; 95% CI, -1.48 to -0.25; P = .01), and lower delta body-weight z-scores (β coefficient-0.13; 95% CI, -0.18 to -0.08; P < .001). Unlike in infants with GA <34 weeks, ACS exposure was associated with slower advancement of enteral feeding, longer time to regain birth weight, and lower delta body-weight z-scores in the ones with GA ≥34 weeks.

CONCLUSION

ACS exposure is associated with poorer enteral feeding process and body growth in our study population, which is more prominent in late preterm infants. A multicenter prospective study and mechanistic studies using animal models are required.

Respiratory distress management in moderate and late preterm infants: The NEOBS Study

OBJECTIVE

To investigate the characteristics and management of respiratory failure (RF) in moderate-to-late preterm infants.

METHODS

NEOBS was a prospective, multicenter, observational study conducted in 46 neonatal intensive care units caring for preterm infants (30+^0/7 to 36+^6/7 weeks of gestation [WG]) in France in 2018. The cohort was stratified into two groups: 30-33 WG (group 1) and 34-36 WG (group 2). Infants with early neonatal RF were included and the outcomes assessed were maternal, pregnancy, and delivery characteristics and how RF was managed.

RESULTS

Of the 560 infants analyzed, 279 were in group 1 and 281 were in group 2. Most pregnancies were singleton (64.1%), and 67.4% of women received prenatal corticosteroids (mostly two doses). Infants were delivered by cesarean section in 59.6% of cases; 91.7% of the infants had an Apgar score ≥7 at 5min. More than 90% of infants were hospitalized post-birth (median duration, 36 and 15 days for groups 1 and 2, respectively). Medical intervention was required for 95.7% and 90.4% of the infants in group 1 and group 2, respectively, and included noninvasive ventilation (continuous positive airway pressure [CPAP]: 88.5% and 82.9%; high-flow nasal cannula: 55.0% and 44.7%, or other) and invasive ventilation (19.7% and 13.2%). The two main diagnoses of RF were respiratory distress syndrome (39.8%) and transient tachypnea of the newborn (57.3%). Surfactant was administered to 22.5% of the infants, using the less invasive surfactant administration (LISA) method for 34.4% of the patients. In the overall population, 8.6% of the infants had respiratory and/or hemodynamic complications.

CONCLUSIONS

The NEOBS study demonstrated that CPAP was widely used in the delivery room and the LISA method was chosen for 34.4% of the surfactant administrations for the management of RF in moderate-to-late preterm infants. The incidence of RF-related complications was low.

Single-course antenatal corticosteroids is related to faster growth in very-low-birth-weight infant

BACKGROUND

Antenatal corticosteroids (ACS) treatment is critical to support survival and lung maturation in preterm infants, however, its effect on feeding and growth is unclear. Prior preterm delivery, it remains uncertain whether ACS treatment should be continued if possible (repeated course ACS), until a certain gestational age is reached. We hypothesized that the association of single-course ACS with feeding competence and postnatal growth outcomes might be different from that of repeated course ACS in very-low-birth-weight preterm infants.

METHODS

A multicenter retrospective cohort study was conducted in very-low-birth-weight preterm infants born at 23-37 weeks' gestation in South China from 2011 to 2014. Data on growth, nutritional and clinical outcomes were collected. Repeated course ACS was defined in this study as two or more courses ACS (more than single-course). Infants were stratified by gestational age (GA), including GA < 28 weeks, 28 weeks ≤ GA < 32 weeks and 32 weeks ≤ GA < 37 weeks. Multiple linear regression and multilevel model were applied to analyze the association of ACS with feeding and growth outcomes.

RESULTS

A total of 841 infants were recruited. The results, just in very-low-birth-weight preterm infants born at 28-32 weeks' gestation, showed both single and repeated course of ACS regimens had shorter intubated ventilation time compared to non-ACS regimen. Single-course ACS promoted the earlier application of amino acid and enteral nutrition, and higher rate of weight increase (15.71; 95%CI 5.54-25.88) than non-ACS after adjusting for potential confounding factors. No associations of repeated course ACS with feeding, mean weight and weight increase rate were observed.

CONCLUSIONS

Single-course ACS was positively related to feeding and growth outcomes in very-low-birth-weight preterm infants born at 28-32 weeks' gestation. However, the similar phenomenon was not observed in the repeated course of ACS regimen.

Controversies in antenatal corticosteroid treatment

Antenatal corticosteroids are now established as one of the cornerstones of therapy in the prevention of neonatal morbidity and mortality prior to preterm birth. Although this practice is widely accepted, a significant number of controversies exist. This review explores the knowledge gaps regarding the use of antenatal corticosteroids in the preterm, late preterm and term populations. Furthermore, the role of antenatal corticosteroids in special populations, such as diabetes, multiple pregnancies and periviable gestations, where high-quality data from randomized controlled trials are lacking, is also considered.

Time and mode of delivery in diabetic pregnancy: a review

The review presents some renewed data on the problem of optimal time and modes of delivery for women with various types of diabetes mellitus (DM 1 and 2, gestational diabetes). The necessity of making the universal delivery strategy algorithm for women with DM comes out of adverse outcomes high frequency, where the main cases are fetal macrosomia, fetal shoulder dystocia and perinatal mortality. Despite significant interest for this issue, there is still no common delivery tactics in the world for pregnant women with carbohydrate metabolism disorders. The main obstacle is evidence-based tests and meta-analysis insufficiency. So far, further studies are necessary to obtain high quality data concerning optimal terms and modes of delivery for women with DM.