Title: Short and longer-term outcomes for women and their children according to intended mode of delivery after previous caesarean section
Funder: Department of Health and Social Care

Abstract: Background: Many countries, including the UK, have seen a rise in their caesarean section rate (now ~25% of all births in UK) leading to an increasing proportion of women embarking on a subsequent pregnancy with a history of previous caesarean section (estimated at ~100,000 women per year in UK). Current UK guidelines advise that pregnant women who have had one or more previous caesarean sections should be counselled about the risks and benefits of elective repeat caesarean section (ERCS) compared to planned vaginal birth after caesarean section (VBAC, also known as trial of labour). However, a number of significant limitations have been highlighted with the existing evidence, and there have been calls for methodologically rigorous studies to assess both the short and longer-term outcomes for women and their children of intended mode of delivery after prior caesarean section and thus fill this evidence gap. Aim and objectives: The overall aim of this research is to provide evidence-based information to facilitate women making informed decisions and choices with respect to planned mode of delivery after previous caesarean section, by investigating the short and longer-term outcomes for women and their children according to intended mode of delivery after previous caesarean section. The specific objectives are: 1. To investigate the effect of ERCS compared to planned VBAC on the:a.short-term health outcomes for the mother b.longer-term health outcomes for the mother 2. To investigate the effect of ERCS compared to planned VBAC on the: a.short-term health outcomes for the baby/child b.longer-term developmental outcomes for the child 3.To explore whether any effects are confounded, mediated or moderated by other factors such as gestational age at delivery or the number of previous caesarean sections a woman has had Proposed methods: A population-based cohort of births to women with a history of previous caesarean section in Scotland (sample size ranging from ~35,000-112,000) will be created using the Scottish Morbidity Record Maternity Inpatient and Day Case dataset (SMR02) with follow up through record linkage to seven other routinely available Scottish national datasets (Scottish Stillbirth and Infant Death survey; Scottish Birth Record; Child Health Surveillance Programme Pre-School system; Scottish Morbidity Record; Prescribing Information System; School census; and the National Records of Scotland Deaths data). The effect of ERCS compared to planned VBAC on the following outcomes will be assessed: maternal intrapartum and postpartum complications/morbidity; breastfeeding; maternal use of psychotropic drugs; pelvic floor surgery in the mother; intrapartum stillbirth and neonatal mortality; neonatal unit admission; and special educational needs of the child. Regression modelling will be used to estimate the effect of intended mode of delivery on outcomes. Potential benefits to patients and the NHS: The proposed research will provide a comprehensive picture of the short and longer-term outcomes for women and their children according to intended mode of delivery after previous caesarean section in a UK population. This will help fill the evidence gap highlighted in the existing literature and current guidelines published by the Royal College of Obstetricians and Gynaecologists (RCOG) and the National Institute for Health and Care Excellence (NICE). Importantly, the information will assist the counselling of pregnant women who have had a previous caesarean section with regard to choice of planned mode of delivery, and thus support informed decision-making as advised by UK guidelines. Understanding the associated risks of mode of delivery also offers the potential to improve outcomes for women and their children. The results will also inform those involved in resource planning, policy development and service provision (such as maternal, neonatal and paediatric healthcare services). These benefits will be supported by informing RCOG and NICE guidelines.

Lay abstract: A caesarean section is an increasingly common operation performed to deliver a baby. Around one in four of all births in the UK are now by caesarean section. A large number of women therefore embark on another pregnancy with a history of previous caesarean section (estimated at ~100,000 women per year in the UK). A woman who has had a caesarean section may be offered either a planned caesarean section or the opportunity to try for a vaginal delivery in her next and subsequent pregnancies. Current UK guidelines advise that such women should be counselled about the benefits and harms of planning to have another caesarean section compared to attempting a vaginal delivery to help with this decision and choice. However, there is little good quality evidence on the associated short and longer-term benefits and harms to women and their children. The main aim of the proposed research is to provide better evidence about this to help women make informed decisions and choices about this aspect of their maternity care. The research will use existing data on births to women who have had one or more previous caesarean sections in Scotland and link it to several other existing Scottish national datasets. The effect of planning to have another caesarean section compared to attempting a vaginal delivery will be studied. This will be done by looking at information recorded in these datasets about what happens to the women and their children during and after birth. In women the effect on the following outcomes will be studied: complications at the time or shortly after birth such as heavy bleeding (haemorrhage) or infection; whether they breastfeed; whether they need medications to treat mental health problems; and whether they need an operation for pelvic floor problems such as leakage of urine. In children, the effect on the following outcomes will be investigated: whether they survive the first month after birth; require intensive medical attention shortly after birth; or have a special educational need such as autism or dyslexia. The results of this study will help women who have had a previous caesarean section make an informed decision and choice about how to plan to give birth in their next pregnancy. Understanding the harms associated with how a woman plans to give birth also offers the potential to improve outcomes for women and their children. The findings will also assist those involved in resource planning, policy development and service provision (such as maternal and child healthcare services). Results will be communicated to those involved in developing national guidelines advising on the care of pregnant women (National Institute for Health and Care Excellence and the Royal College of Obstetricians and Gynaecologists); giving talks at conferences; and publishing the results in journals. I will also work with service user and voluntary groups such as the Birth Trauma Association and the NCT (formerly the National Childbirth Trust) to make sure the results are communicated in a way that is understandable and accessible to women, their partners and the public.

Research activity codes: 7.1 INDIVIDUAL CARE NEEDS
Health categories: REPRODUCTIVE HEALTH AND CHILDBIRTH