INTRODUCTION
Preterm birth (less than 37 weeks’ gestation) accounts for around 11% of all live births worldwide, poses risks of adverse outcomes and can be attributed 35% of deaths among newborns.1-3 Preterm birth represents a significant health burden worldwide, mainly in Low-to-Middle-Income Countries (LMICs).
Respiratory distress Syndrome (RDS) is a serious complication of preterm birth and the primary cause of early neonatal death, lifelong disability and poor quality of life. RDS affects up to half of babies born before 28 weeks and a third of babies born before 32 weeks.4 Antenatal corticosteroids for preterm birth prevent RDS and neonatal mortality5, however there still persist doubts about the applicability in LMICs6 and there is no consensus regarding the type of corticosteroid to use; nor the dose, frequency, timing of use or the route of administration. Currently, either betamethasone or dexamethasone are the recommended corticosteroid for clinical practice. The World Health Organization (WHO) guidelines7 states that there is no conclusive evidence that would support a recommendation of one over the other. We acknowledged that dexamethasone has an advantage over betamethasone in terms of lower cost and wider availability, and it is currently listed on the WHO Essential Medicine List and in WHO’s Managing complications in pregnancy and childbirth guide.8
Two Cochrane systematic reviews have synthesized the effects of corticosteroids. Brownfoot et al. 20139 and Roberts et al. 201710, which compared any corticosteroids for preterm birth against each other, or against placebo, respectively. Although Brownfoot et al.9 focused on direct comparisons, authors also assessed indirect comparisons of corticosteroids with placebo for some outcomes based on Roberts 200611. While the indirect estimates suggest no significant differences between corticosteroids for puerperal sepsis, a significant difference favoured betamethasone for chorioamnionitis.11
Direct comparisons in Brownfoot 20139 showed that dexamethasone may have some benefits compared to betamethasone such as less intraventricular haemorrhage. Roberts 201710 suggested that dexamethasone may also be associated with a higher rate of chorioamnionitis. New additional published trials12-14, that almost doubled the previous number of participants involved in direct comparisons, warranted a network meta-analysis (NMA), to urgently define this hot topic. Our aim was to assess the comparative clinical effectiveness and safety of dexamethasone versus betamethasone for women at risk of preterm birth.