Introduction: An acardiac fetus is the most severe malformation seen in humans. It is an extremely rare complication, occurring in approximately 1% of all monozygotic twin gestations, with an incidence of about 1 in 35,000 births. This malformation happens as a result of the syndrome of reversed arterial perfusion of the acardiac twin from the other normal fetus (pump twin), due to the presence of arterio-arterial anastomoses in a monochorionic placenta. Several obstetric and perinatal complications have been associated to this anomaly and several treatments have been proposed to reduce the morbimortality of the pump twin. There's no report in MEDLINE about the treatment of twin gestations with acardiac fetus through septostomy.
Case report: The present article reports a case of reversed arterial perfusion sequence complicated by polyhydramnios diagnosed at 19th week of pregnancy, treated with septostomy and serial amniodrainage.
Discussion: This case presented it demonstrate favorable development of the gestation, with labor happening at 35 weeks gestation and pump twin presenting good vitality conditions. In cases with no major factors of bad prognosis, septostomy combined with amniodrainage could be an interesting therapeutic option for a safe and efficacious management of selected cases of TRAP sequence.