Obstetrics and Gynaecologycommon
A 28-year-old primigravida gives birth vaginally at 38 weeks gestation. During labour she was commenced on oral labetalol for blood pressure readings of 160/108 mmHg with a urine protein-to-creatinine ratio of 60 mg/mmol (normal less than 30). The third stage was actively managed with intramuscular oxytocin, but 20 minutes after delivery of the placenta there is a continuous trickle of blood with an estimated loss of 800 mL. The uterus is soft, firms with massage but then relaxes, and an oxytocin infusion has been commenced. Which one of the following additional uterotonic agents is contraindicated in this patient?