Planned early delivery versus expectant management to reduce adverse pregnancy outcomes in pre-eclampsia in a low- and middle-income setting: study protocol for a randomised controlled trial (CRADLE-4 Trial)

Background Pre-eclampsia is a pregnancy complication characterised by high blood pressure and multi-organ dysfunction in the mother. It is a leading contributor to maternal and perinatal mortality, with 99% of these deaths occurring in low- and middle-income countries (LMIC). Whilst clear guidelines exist for management of early-onset (< 34 weeks) and term (≥ 37 weeks) disease, the optimal timing of delivery in pre-eclampsia between 34 + 0 and 36 + 6 weeks is less clear. In a high-income setting, delivery may improve maternal outcomes without detriment to the baby, but this intervention is yet to be evaluated in LMIC. Methods The CRADLE-4 Trial is a non-masked, randomised controlled trial comparing planned early delivery (initiation of delivery within 48 h of randomisation) with routine care (expectant management) in women with pre-eclampsia between 34 + 0 and 36 + 6 weeks’ gestation in India and Zambia. The primary objective is to establish whether a policy of planned early delivery can reduce adverse maternal outcomes, without increasing severe neonatal morbidity. Discussion The World Health Organization recommends delivery for all women with pre-eclampsia from 37 weeks onwards, based on evidence showing clear maternal benefit without increased neonatal risk. Before 34 weeks, watchful waiting is preferred, with delivery recommended only when there is severe maternal or fetal compromise, due to the neonatal risks associated with early preterm delivery. Currently, there is a lack of guidance for clinicians managing women with pre-eclampsia between 34 + 0 and 36 + 6 weeks. Early delivery benefits the mother but may increase the need for neonatal unit admission in the infant (albeit without serious morbidity at this gestation). On the other hand, waiting to deliver may increase the risk of stillbirth, fetal growth restriction and hypoxic brain injury in the neonate as a result of severe maternal complications. This is especially true for LMIC where there is a higher prevalence of adverse events. The balance of risks and benefits therefore needs to be carefully assessed before making firm recommendations. This is the first trial evaluating the optimal timing of delivery in pre-eclampsia in LMIC, where resources and disease burden are considerably different. Trial registration ISRCTN 10672137 . Registered on 28 November 2019.