Pharmacokinetics of Oxytocin at Cesarean Delivery

The Pharmacokinetics of Oxytocin in Pregnant Women Undergoing Cesarean Delivery - a Feasibility Pilot Study

The primary objective is to obtain data to inform the design of a population pharmacokinetic study of oxytocin after administration at CD as per standard institutional practice.

In this pilot study the investigators will compare plasma oxytocin concentrations measured in arterial and venous blood, after oxytocin administration at cesarean delivery, in order to assess the validity of venous samples. They will also measure oxytocinase to explore how levels vary around the time of delivery of the placenta and to assess the effect that this may have on the metabolism of oxytocin.

Inclusion Criteria:

• Term singleton pregnancy
• Age 18-45 years of age
• ASA classification 2 or 3
• Scheduled cesarean delivery under neuraxial anaesthesia

Exclusion Criteria:

• Age or ASA classification outside of inclusion criteria
• Need for general anaesthesia
• Absence of consent
• Inability to communicate in English or other barrier to providing informed consent