Second-degree atrioventricular block after administration of methylergometrine for treatment of uterine atony during cesarean section.

Mortality due to cardiovascular disease in pregnancy is a growing problem in developed countries, being nowadays the leading cause of maternal death. Within this group, the most common cause of death are congenital or acquired heart diseases, representing a challenge in the management of these patients, since the pregnancy-related physiological alterations can impair their basal condition and treatment. We present the case of a 34-year-old patient, without any relevant pathological antecedents, who developed a second-degree atrioventricular block, Mobitz type I, following the administration of methylergometrine during cesarean section due to failure to progress in labour. We emphasize the importance of considering the side effects of commonly used drugs in pregnant patients, despite rare possibility of some adverse reactions.