Preoperative ultrasonography is necessary for all cases 14 weeks and beyond. Intraoperative real-time ultrasonography helps to locate fetal parts within the uterus. Paracervically administered vasopressin has been demon-strated to significantly reduce bleeding, but vasopressin must be used with caution. A maximum of 4 units should be used, and it is usually diluted with saline or Xylocaine. Vasopressin should not be used in women with heart disease or hypertension.
Intravenous oxytocin is begun early in the procedure, just after rupture of the membranes.
The use of oxytocin and intracervical vasopressin may reduce this risk. To avoid negative pressure in the uterine vasculature, the Trendelenburg position should not be used. After the procedure, the operator must examine the fetal parts carefully to be sure that evacuation is complete. If the fetal calvarium has been retained in the uterus and gentle attempts at extraction fail, the procedure should be completed under ultrasound guidance. If this is not available, it is best to stop, administer an oxytocin infusion for 2 hours, and try again.