PRECIOUS (PREterm Caesarean/vaginal birth & IVH/OUtcomeS) Study: Does mode of birth reduce the risk of death or brain injury in very preterm babies?

Aims of this work
Using routine (already collected) data we will test if there is a difference in the rate of brain injury or death between the babies who are born by caesarean and those born vaginally, without additional intervention. We will use this to plan a future clinical trial to find out the best way  to deliver premature babies.

What we already know
Babies born very preterm (before  32 weeks  of  gestation) are at high risk of dying or developing brain injuries around birth. Some are born by caesarean section and these babies appear to have a better chance of surviving and escaping brain  injury than those born  vaginally.  What we do not know is if this is a real finding, or simply that babies who are less sick are delivered by caesarean. We also don’t know in which situations mothers, doctors, midwives and nurses are most uncertain around the right decision, and which groups of babies might benefit most to be included in a future trial.

What we hope to discover
We think that a future randomised trial, where mode of birth is decided by chance, is the only way to really work out what the best way to deliver premature  babies  is. We can’t do such a trial yet because we don’t know enough about how to best design such a trial.

We will get this knowledge using, already collected, routine data. First we will identify groups of babies born preterm, with similar relevant characteristics, some of whom are born by caesarean section and others by vaginal birth. In some of these pregnancies the doctors recommend, and the mothers appear to choose, one mode of delivery or another. We will then identify if their mode of birth is associated with a better or worse outcome.

Second, we will then use the same data, together with a technique known as a “Emulated Target Trial”, to work out if babies are more likely to survive without brain injury if we ran a randomised trial in different groups of women. From this we will identify how useful a trial may be and what the likely benefits of optimising the mode of birth of these very preterm infants could be. This will allow us to design the best, and most efficient, clinical trial in the future, to obtain the vital  data we need to guide mothers to base their mode of birth decisions.

Public involvement (PPI)
We have worked with women, families and the public, to identify important outcomes, and how much difference in these outcomes would need to be seen to influence the decisions around the mode of birth. Next we will engage patient representatives to guide which groups of babies we should compare, guide the methods we use, the interpretation and importance of the results, what recommendations should be made, and what areas need to be clarified with further research.

Communicating the results
We will share our findings and outputs with other healthcare professionals in scientific journals and at conferences. We will also share them with health guideline producers. Members of the public will be informed through national charities and patient organisations.