Maternal Haemodynamic Changes After Crystalloid Co-loading and Phenylephrine Versus Phenylephrine Alone During Spinal Anaesthesia for Elective Caesarean Delivery

Inclusion Criteria: * Ability to give informed consent * Term uncomplicated singleton pregnancy * Undergoing elective caesarean section under spinal anaesthesia * Weight: 50-100kg * Height: 150-180cm * Healthy term fetus Exclusion Criteria: * Inability to give informed consent * Multiple pregnancy * Clinically significant concomitant disease states (e.g. hypertension, cardiac disease, severe asthma requiring regular medication, comorbidities affecting the autonomous nervous system, renal disease) * On any cardiovascular medication * Complications of pregnancy (e.g. preeclampsia, intrauterine growth restriction, fetal malformations) * Known or suspected non-compliance, drug or alcohol abuse * Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia of the participant, * Participation in another study with investigational drug within the 30 days preceding and during the present study, * Previous enrolment into the current study, * Enrolment of the investigator, his/her family members, employees and other dependent persons * Any fetal pathology (e.g. fetal malformations, rupture of membranes before caesarean section, oligohydramnios, polyhydramnios, suspected chorioamnionitis)