The role of antenatal corticosteroids in improving neonatal outcomes

M R C O G PA R T 2 · S O S P O C K E T C A R D · K N O W L E D G E A R E A 5 – A N T E N ATA L C A R E

Antenatal Corticosteroids and Neonatal Outcomes Busuulwa P et al. The role of antenatal corticosteroids in improving neonatal outcomes. TOG 2021;23:246–257. doi:10.1111/tog.12768

24+0–33+6 0.66 18–36h WEEKS: SINGLE-COURSE ACS WINDOW RR RDS, ACS VS NONE (COCHRANE, 30 TRIALS) OPTIMAL ACS-TO-DELIVERY INTERVAL FOR MAX (WHO/NICE/ACOG) BENEFIT

DO N' T-M IS S FA C TS

1. ACS benefit is time-limited: only clear benefit if delivery occurs within 7 days of administration – accurate prediction of preterm birth risk is essential

2. Standard course: betamethasone 12 mg IM ×2, 24h apart OR dexamethasone 6 mg IM ×4, 12h apart; single course 24+0–33+6 weeks (WHO/NICE/ACOG)

3. Greatest mortality benefit if given 18–36 hours pre-delivery; >7 days before delivery linked to a 40% relative ↑ in mortality vs the 1–7 day window

4. NICE: do not routinely repeat ACS courses; ACOG/WHO allow a single rescue course if still high risk and ≥7–14 days from last course

5. Repeat ACS courses consistently ↓birthweight/growth (ACTORDS, MACS, NICHD); MACS 5-year data show repeat- exposed infants born at term have ↑death/disability (OR 1.69) and ↑neurosensory disability (OR 3.70)

6. ALPS trial (late preterm 34+0–36+5 weeks): ACS ↓respiratory morbidity but ↑neonatal hypoglycaemia (24.0% vs 15.0%)

7. ACT trial in LMIC: ACS associated with ↑28-day mortality (RR 1.12) in the whole study population – high-income evidence of benefit does not automatically apply to LMIC settings

8. Cochrane review of elective term CS: ACS ↓RDS by 52% and ↓TTN by 57%, but all 4 trials at risk of bias – interpret with caution

TRIAL NAME QUICK-REFERENCE

ACTORDS – repeat q7d, ↓RDS/oxygen need, ↓birthweight

MACS – repeat q14d, no morbidity benefit, ↓growth, term subgroup harm at 5y

NICHD – repeat q7d (max 4), stopped early for safety/growth concerns ALPS – late preterm, ↓resp. support but ↑hypoglycaemia

ASTECS – elective term CS, ↓RDS admissions but small absolute numbers ACT – LMIC, ↑overall mortality in whole population

ABBREVIATION KEY

ACS — antenatal corticosteroids WHO — World Health Organization

RDS — respiratory distress syndrome 11β-HSD2 — 11β-hydroxysteroid dehydrogenase type 2

NEC — necrotising enterocolitis GR — glucocorticoid receptor

IVH — intraventricular haemorrhage HPA — hypothalamic–pituitary axis

PVL — periventricular leukomalacia fFN — fetal fibronectin

BPD — bronchopulmonary dysplasia AUROC — area under the receiver operating characteristic curve

TTN — transient tachypnoea of the newborn RCT — randomised controlled trial

PPROM — preterm prelabour rupture of membranes RR — relative risk

NICE — National Institute for Health and Care Excellence OR — odds ratio

ACOG — American College of Obstetricians and Gynecologists HR — hazard ratio CI — confidence interval ALPS — Antenatal Late Preterm Steroids trial

MACS — Multiple Courses of Antenatal Corticosteroids for Preterm ASTECS — Antenatal Steroids for Term Caesarean Section trial Birth trial ASTEROID — betamethasone vs dexamethasone RCT ACTORDS — Australasian Collaborative Trial of Repeat Doses of ACT — Antenatal Corticosteroids Trial (LMIC cluster RCT) Steroids LMIC — low- and middle-income countries NICHD — National Institute of Child Health and Human Development study

Source: The Obstetrician & Gynaecologist (TOG), RCOG journal — doi:10.1111/tog.12768

Clinically reviewed by NHS obstetricians and gynaecologists

MRCOG AI is an independent educational tool. It is not affiliated with, endorsed by, or connected to the Royal College of Obstetricians and Gynaecologists (RCOG).