Pharmacological prevention of bleeding at caesarean section

During Caesarean sections, a blood loss of less than 1000 mL can be considered appropriate. The incidence of serious forms of excessive postpartum bleeding, i.e., of those associated with increased maternal mortality or significant morbidity (a blood loss greater than 1500 mL at Caesarean section), is reported to be 1/1000 and 3.5–5/1000 live births in developed and developing countries, respectively. In developing countries, more than 100,000 women die from this obstetric complication every year. The introduction of the prophylactic administration of uterotonic drugs during the third stage of labour results, even in the case of a Caesarean section, in a decrease in blood loss by more than 40%, and thus significantly reduces the need for blood substitutes in the intra- and postoperative period; therefore, it is generally recommended. Oxytocin is a uterotonic agent routinely administered to prevent uterine atony. Carbetocin, a novel synthetic analogue of oxytocin, has a four to ten times longer half-life (40 mins) compared to oxytocin and can be used in a one-time intravenous injection. Carbetocin can also be given intramuscularly. There is evidence of a higher efficacy of an intravenous injection of 100 μg of carbetocin on myometrial retraction at Caesarean section as compared to an 8-hour IV infusion of oxytocin. In terms of adverse effects, the novel uterotonic agent is well tolerated and combines the safety of oxytocin with the long-lasting action of ergot alkaloids. When available, carbetocin should be used as the drug of choice to prevent postpartum uterine hypotony/atony at Caesarean section.

Keywords: Key words: Caesarean section, obstetric hemorrhage, uterine contraction, carbetocin, oxytocin.