The RETHINK Study Protocol: to determine if pregnant women who pain catastrophise are more likely to attend hospital during the latent phase of labour.

Abstract

Background: Women experiencing an uncomplicated pregnancy are at increased risk of obstetric intervention if admitted to hospital during latent labour. Understanding which factors influence the time that women are admitted to hospital when in labour is crucial to reducing unnecessary obstetric intervention. There is evidence that some women seek early hospital admission for pain relief, and it is possible that women who pain catastrophise may be more likely to do this. Studies have yet to consider whether pain catastrophising impacts the timing of hospital admission. This study will consider the prevalence of pain catastrophising in the study group, and its sway on the timing of hospital admission, labour choices and birth outcomes. Aim: This study aims to identify the prevalence of pain catastrophising during pregnancy and examine whether it has an impact on the timing of hospital admission when women are in labour. Ethics: A favourable ethical opinion was received on 3 June 2020 by a National Health Service (NHS) local research ethics committee. Study approval was granted on the 4 June 2020 by the Health Research Authority (HRA) and Health and Care Research Wales (HCRW). Methods: This is a pragmatic, quasi-experimental study. Primigravid women, experiencing an uncomplicated pregnancy and planning to birth in an NHS hospital trust in England, will be recruited between 25 and 33 weeks and 6 days gestation. To estimate prevalence, with five per cent precision, requires a target sample size of 384. This was based on a study of women of reproductive age, calculated with the aid of a statistician and verified using the app WinPepi. Participants will complete two online questionnaires, one antenatal and one postpartum. The antenatal questionnaire includes the Pain Catastrophizing Scale (PCS), and the Wijma Delivery Expectancy Questionnaire (WDEQ-A). Analysis will divide the sample according to whether participants catastrophise pain or not. The primary outcome measure is admission to hospital in latent labour. Secondary outcome measures include pre-specified birth outcomes. Logistic regression will be used to assess if pain catastrophising is a predictor of hospital admission during latent labour. Other explanatory factors (for example, socio-economic) will be identified. The alpha level will be p ≤ 0.05. Discussion: It is hypothesised that the PCS can be used as a predictive tool to identify who will seek hospital admission during latent labour. Identifying whether pain catastrophising is a risk factor for early hospital admission will facilitate early intervention to support and empower women to manage their labour pain.