PlaCEUS: Feasibility Study of Contrast-enhanced Ultrasound to Visualize Maternal Uterine Spiral Arteries Postpartum.

During pregnancy, unique blood vessels form within the uterine wall, known as spiral arteries. These vessels originate from the uterine artery, which is the main artery supplying blood to the uterus. Throughout pregnancy, spiral arteries undergo significant changes to increase blood and oxygen flow to the placenta, ensuring the developing baby receives adequate nutrients. When these arteries fail to remodel properly, complications such as pre-eclampsia or fetal growth restriction can occur. Until now, direct observation and evaluation of spiral arteries during pregnancy has not been feasible. Contrast-enhanced ultrasound may provide a breakthrough in this area. In this study, the investigators aim to use this imaging technique to visualize spiral arteries after the placenta has been delivered. If successful, this could allow to assess their structural quality. Additionally, the investigators will employ ultrasound to monitor physiological changes in the uterine artery during late pregnancy (after 37 weeks), during labour, and postpartum. By conducting these measurements, the investigators hope to develop methods for detecting spiral artery abnormalities earlier in pregnancy. Early identification could enable timely interventions and help prevent severe complications.