Investigating haemodynamic changes during vaginal delivery in low-risk pregnant women and the association between haemodynamic and adverse pregnancy outcomes: an ambispective cohort study protocol

Introduction The progressive adaptation of the maternal cardiovascular system throughout pregnancy is essential to maintaining adequate uteroplacental circulation and meeting maternal physiological demands. In recent years, maternal haemodynamic parameters have gained attention as useful indicators for screening and managing pregnancy, particularly for identifying women at high risk for complications and predicting adverse pregnancy outcomes. The aim of this study is to assess the trajectory of haemodynamic parameters during labour, establish reference ranges for different stages of labour and explore the association between haemodynamics and adverse pregnancy outcomes. Methods and analysis This is an ambispective observational cohort study conducted in a tertiary hospital in Chongqing, China. A total of 2800 pregnant women will be enrolled. After hospital admission and providing written informed consent, participants will complete a demographic questionnaire. Data collection will include maternal baseline characteristics, haemodynamic parameters at multiple stages of labour and maternal and newborn outcomes. These data will allow comprehensive analysis of haemodynamic changes during labour in women undergoing vaginal delivery. Ethics and dissemination This study has been approved by the Research Ethics Committee of the First Affiliated Hospital of Chongqing Medical University (ethics approval number: 2024–406-01). Participation is voluntary and initiated only after obtaining written informed consent. The findings will be disseminated through presentations at national and international conferences and through publications in peer-reviewed scientific journals. Trial registration number ChiCTR2500097643.