Haemodynamics during Vaginal and Caesarean Delivery in Healthy Parturients

Abstract

Childbirth may have a profound impact on maternal circulation. Vaginal delivery exposes the parturient to cardiovascular stress, but the evidence is very limited. Spinal hypotension during caesarean delivery has been studied extensively, but improving its prevention still is an international research target. This project aimed to contribute to understanding and optimisation of maternal circulation during childbirth, by studying haemodynamics with continuous minimally invasive monitoring (LiDCOplus) in healthy parturients. We showed that low-dose phenylephrine infusion is superior to leg wrapping for prevention of spinal hypotension during caesarean delivery. Phenylephrine primarily counteracts the profound arterial vasodilatation caused by spinal anaesthesia, whereas leg wrapping limits modest venodilatation. We found that haemodynamic changes during contractions may be pronounced already in early active labour. The extent of these changes increased with progressing labour, whereas haemodynamic values between contractions were similar throughout labour. Stable haemodynamics immediately postpartum query the common belief that delivery leads to a significant myometrial autotransfusion.