ACTA2 mutation and postpartum hemorrhage: a case report

Kylie Cooper, Stephen Brown

ACTA2 encodes smooth muscle specific α-actin, a critical component or the contractile complex of vascular smooth muscle. Mutations in ACTA2 are the most common genetic cause of thoracic aortic aneurysm, and are also the cause of other disorders, including Moyamoya disease, coronary artery disease and stroke as well as Multisystemic Smooth Muscle Dysfunction Syndrome. We note that ACTA2 is also expressed in uterine smooth muscle, and this raises the possibility that women harboring ACTA2 mutations might exhibit uterine smooth muscle dysfunction. We present a young woman whose ACTA2 mutation was ascertained during pregnancy because of her father's history of dissecting aneurysms. She was delivered at full term by cesarean section and subsequently had severe uterine hemorrhage due to uterine atony. Although her atony was successfully treated with uterotonic medications, she required blood transfusion. This case raises the possibility that women with ACTA2 mutations may be at risk of uterine muscle dysfunction and hemorrhage. Obstetricians should be alerted to and prepared for this possibility.