PRECIOUS study (PREterm Caesarean/vaginal birth and IVH/OUtcomeS): does mode of birth reduce the risk of death or brain injury in very preterm babies? A cohort and emulated target trial protocol.

INTRODUCTION

Very preterm babies are at risk of poor neurodevelopmental outcomes and death. Intraventricular haemorrhage (IVH) after birth is the most prevalent cause of this. Birth by caesarean section may protect against IVH in very preterm babies, but the evidence is limited. The aim is to identify and obtain the quantitative evidence needed to inform a future definitive clinical trial to determine the optimal mode of delivery in preterm birth.

METHODS AND ANALYSIS

We will use three broad workstreams (WS) to answer complementary questions. WSs 1 and 2 involve the analysis of routinely recorded national clinical data held in an established research database. In WS1 (October 2023-March 2024), we will use conventional methods to identify what is needed to undertake a trial: the population of interest, areas of equipoise and a plausible range of effect sizes. In WS2 (April 2024-October 2024), using an emulated target trial framework, we will attempt to make inferences about the treatment effect from such a future trial and will identify potential challenges in recruitment and estimate likely 'intention-to-treat' versus 'per-protocol' profiles; these analyses will also be useful for power calculations for future possible trials. In WS3 (October 2024-March 2025), we will convene a consensus meeting with key stakeholders, supported by a clinical trials unit, to develop a multicentre clinical trial to identify the optimal mode of birth for preterm deliveries.

ETHICS AND DISSEMINATION

In this study, we will use deidentified data held in the National Neonatal Research Database (NNRD), an established national population database; parents can opt out of their baby's data being held in the NNRD. HRA/Health and Care Research Wales and National Health Service (NHS) study-specific Research Ethics Committee approval (London-Queen Square Research Ethics Committee) (Ref: 23/LO/0826) ethical approval has been obtained. Key outputs of the PRECIOUS (PREterm Caesarean/vaginal birth and IVH/OUutcomeS) study include the identification of the data, and accordingly of the multidisciplinary team required, to develop, gain funding and complete, a clinical trial to definitively identify the optimal mode of delivery for preterm infants and their mothers.