The study will establish whether the use of ultrasound scanning with a purpose built probe will aid the insertion of the needles for epidural and spinal anaesthesia for obese women undergoing elective caesarean section The study group will be 46 obese women (defined by the ratio of height to weight) at time of initial booking ultrasound scan, undergoing routine caesarean section with no serious illnesses that are both willing and able to provide informed consent prior to spinal epidural anaesthesia. Patients will be excluded if they have signs or symptoms of systemic or local infection, if they have a history of previous spinal surgery, a blood clotting abnormities.