Research aims to reassure mothers and clinicians around mode of delivery for premature babies

Research funded by Health and Care Research Wales at Cardiff University has found that mode of birth may have little impact on likelihood of death or of brain injury for very premature babies.

Babies born before 32 weeks are at higher risk of brain injury or death during delivery. However, there is currently no agreement on whether caesarean section or vaginal birth for these babies.

While studies have been conducted to examine which mode of birth had better maternal and neonatal outcomes in preterm births, findings still remain unclear. This study, PRECIOUS, evaluated routinely-collected data to establish if there was a difference in the rate of brain injury or death between the babies born by caesarean and those born vaginally. This data was then used to model a hypothetical clinical trial. This technique, known as “target trial emulation” is often used to address research questions that cannot easily be investigated, for logistical or ethical reasons.

It found little evidence to indicate prioritising one mode of birth over the other. Researchers hope the results will help reassure mothers, families and clinicians that, in most cases, they can continue to make the best decision about mode of birth on a case-by-case basis. The study was recently published in leading international journal, The Journal of Maternal-Fetal and Neonatal Medicine.

Jane from Cardiff gave birth to identical twin sons, Ayrton and Bevan, at 30 weeks via emergency caesarean section. She was patient representative and co-applicant on the PRECIOUS study.

Jane said, “I was monitored closely from 20 weeks as the babies shared one placenta [called monochorionic twins]. This meant Ayrton had reduced blood flow which affected his growth. [I]

had weekly ultrasound scans at the University Hospital of Wales in Cardiff. At 22 weeks the scan showed problems with the blood flow and reduced amniotic fluid to Ayrton. My consultant wanted a second opinion on managing the pregnancy and arranged with King’s College Hospital in London for me to be seen the next day.

“I was given steroids at 27 weeks to help the babies’ lungs mature and at 28 weeks was told they were highly likely to be born early. When I was admitted to hospital in Cardiff just before 30 weeks for close monitoring I knew that it was likely that they would be delivered soon.

“I was scanned on the second day after being admitted. The blood flow from the placenta to Ayrton had deteriorated to the extent that it was unsustainable, meaning he had to be delivered as soon as possible. I was worried that they would be born so early, but the consultation between the teams in Cardiff and London helped reassure me and I could trust they were making the best decision they could. The medical team left the boys in utero for as long as possible, then made a swift decision when the time came for them to be delivered. The only thing that stopped them being delivered immediately was the packet of Jaffa Cakes that I had just eaten and therefore it had to be five hours later!”

The boys were delivered by emergency caesarean section, Ayrton weighing 780 grammes, and Bevan 1.3kg. Bevan spent seven weeks in the neonatal intensive care unit (NICU) at the University Hospital of Wales and Ayrton 13 weeks, before the family were finally able to be together at home, three weeks after the boys’ due date.

Jane continued, “The boys are now 22. Even 22 years ago I realised how important medical research was to their survival and healthy outcome. It has been very rewarding to use my experience and be just a small part of on-going research around pre-term birth.

“Pregnancy is such an anxious time and going into premature labour or being aware that your baby or babies might be delivered early just exacerbates this. Mothers will want to know that the mode of birth, where there is an option, will be the most appropriate for them and their baby. The results of this research seem to suggest that mode of birth may make little difference in most preterm babies. The decision-making process can focus on other factors affecting the mother and baby and be centred on them.”

Dr David Odd, Consultant Neonatologist and Senior Lecturer, Cardiff University, led the study. Dr Odd said, “There are so many factors at play when it comes to deciding whether to deliver a baby by caesarean section or vaginally. Things can be even more complicated when the baby is very premature.

“Historically, clinicians have not had enough evidence to show the effects of a policy of one mode of delivery over the other. Many research teams have tried to answer that question over the years but to put it simply, nobody knows. The best way would be to conduct a randomised controlled trial (RCT), but it has proved difficult to recruit enough women and babies to give reliable results.

“By modelling what an effective RCT would look like, we found that even if we did manage to recruit the tens of thousands of mothers to such a study, the difference in outcomes still wouldn’t reliably indicate prioritising one mode of birth over the other in most cases. Being able to take this one particular factor out of the decision process may help to reassure families and clinicians that they can continue to make the best decision based on each individual mother and baby’s circumstances.

“It could also save millions of pounds on funding a future RCT, where recruitment targets would be unachievably high, only to conclude there is no observable impact of mode of delivery on risk of brain injury. This shows the importance of research to tackle these tricky questions, support clinicians and families, and protect resources.”

Janet Scott, Head of Saving Babies’ Lives team at leading pregnancy and baby loss charity Sands, said, “We’re proud to have contributed to this important research funded by Health and Care Research Wales, which offers reassurance to families and clinicians navigating the complexities of preterm birth. Sands made a significant contribution to the findings by sharing the perspectives of bereaved parents during the study’s development, ensuring that their voices shaped the research in a meaningful way. This latest evidence will mean that mothers and birthing people, together with healthcare professionals, can focus on informed choice and personal preference, knowing that the way the baby is born does not affect the outcome.”

Source: Sands

Image: Canva

Staff Writer