Analysis of Factors Associated With The Occurrence of Amniotic Fluid Entry in Patients Undergoing Caesarean Section

All patients were routinely fasted for 8 h and abstained from drinking for 4 h. After entering the operating theatre, intravenous access was opened, and blood pressure, heart rate, electrocardiogram, oxygen saturation and patient's symptoms were continuously monitored during the operation. After obtaining informed consent for anaesthesia from the patient and his family, intrathecal anaesthesia or general anaesthesia was administered according to the situation. Venous blood was drawn from the patient 30 min after the foetus was dissected out, and samples were preserved to measure the concentration of serum STN antigen and the concentration of complement C4; data were collected through the resident workstation system and the manual anaesthesia system, and the patient's information included age, history of allergy, number of deliveries, and history of combining with other illnesses; and the pregnancy information included Placenta type, amniotic fluid, hypertensive disorders of pregnancy, and whether or not the pregnancy was multiple; delivery data included whether or not elective caesarean section was performed, operator factors, intensity of contractions, method of rupture of membranes, and anaesthesia method.