Table 2.
Studies by gestation and outcomes (country) | Inclusion criteria | ACS treatment (type of ACS) | Risk of bias assessment (Cochrane RoB*) in order R, D, Mi, Me, S, O |
---|---|---|---|
Proportion of infants | |||
Born at term: | |||
Schmitz 2022 (France)54 | • Singleton pregnancy at risk of preterm birth between 2017 and 2019 • Gestational age <32 weeks at trial entry • Received 1 dose of ACS before trial entry • Age ≥18 years |
1 course betamethasone v placebo | +, + ,+, +, + , + |
WHO ACTION-1 Trial Collaborators 2020 (international)55 | • Singleton or multiple pregnancy between 2017 and 2019 • Gestational age 26-33+6 weeks at trial entry • No previous ACS exposure but planned or expected birth ≤48 hours |
1 course dexamethasone with one potential repeat course if birth did not occur after 7 days v placebo | +, +, +, +, +, + |
Crowther 2006 (Australia and New Zealand)56 | • Single, twin, or triplet pregnancy between 1998 and 2004 • Gestational age <32 weeks at trial entry • Received 1 complete course of ACS ≥7 days previously and remained at risk of preterm birth • No contraindication to further corticosteroids |
Repeat dose betamethasone v placebo | + ,+ ,+, + ,+ , + |
Danesh 2012 (Iran)57 | • Singleton pregnancy at risk of preterm birth in 2011 • Gestational age 24-34 weeks at trial entry • 16-45 years of age at high risk of preterm labour with intact membranes or PPROM • Residence in Isfahan, low Bishop Score (≤5), non-smoker, and hospital admission ≥3 days |
1 course betamethasone v 1 course dexamethasone | +, + ,+, + ,?, ? |
Born late preterm: | |||
Schmitz 2022 (France)54 | • Singleton pregnancy at risk of preterm birth between 2017 and 2019 • Gestational age <32 weeks at trial entry • Received 1 dose of ACS before trial entry • Age ≥18 years |
1 course betamethasone v placebo | + ,+ ,+, +, +, + |
Crowther 2006 (Australia and New Zealand)56 | • Single, twin, or triplet pregnancy between 1998 and 2004 • Gestational age <32 weeks at trial entry • Received 1 complete course of ACS ≥7 days previously and remained at risk of preterm birth • No contraindication to further corticosteroids |
Repeat dose betamethasone v placebo | + ,+ ,+, + ,+, + |
Peltoniemi 2007 (Finland)58 | • Singleton or multiple pregnancy between 2001 and 2005 • Gestational age <34 weeks at trial entry • Received 1 complete course ≥7 days before trial entry and preterm birth was imminent • High risk of spontaneous delivery <48 hours indicated by cervical opening ≥3 cm, regular contractions, or PPROM |
1 repeat dose betamethasone v placebo | +,+, +, +, ?, ? |
Born at term/late preterm (combined): | |||
Schmitz 2022 (France)54 | • Singleton pregnancy at risk of preterm birth between 2017 and 2019 • Gestational age <32 weeks at trial entry • Received 1 dose of ACS before trial entry • Age ≥18 years |
1 course betamethasone v placebo | +, +, +, +, +, + |
McEvoy 2010 (USA)59 | • Singleton or twin pregnancy between 2001 and 2007 • Gestational age <34 weeks at trial entry • Received 1 complete course of ACS ≥14 days previously and remained at risk of preterm birth |
1 repeat course betamethasone v placebo | +, +, +, +, +, + |
Garite 2009 (USA)60 | • Singleton or twin pregnancy between 2003 and 2008 • Gestational age 25-32+6 weeks at trial entry • Received 1 complete course of ACS ≥14 days before enrolment and <30 weeks • Recurrent or continued risk of preterm birth within next 7 days |
1 repeat course betamethasone or dexamethasone v placebo | +, +, +, +, +, + |
Crowther 2006 (Australia and New Zealand)56 | • Single, twin, or triplet pregnancy between 1998 and 2004 • Gestational age <32 weeks at trial entry • Received 1 complete course of ACS ≥7 days ago and remained at risk of preterm birth • No contraindication to further corticosteroids |
Repeat dose betamethasone v placebo | +, +, +, +, +, + |
ACS=antenatal corticosteroids; PPROM=preterm premature rupture of membranes; RoB=risk of bias; WHO=World Health Organization.
Cochrane RoB 2 used for randomised controlled trials: +=low risk of bias; −=high risk of bias; ?=some concerns about bias; D=bias due to deviations from intended interventions; Me=bias in measurement of outcome; Mi=bias due to missing outcome data; O=overall risk in bias; R=bias arising from randomisation process; S=bias in selection of reported results.