Twin reversed arterial perfusion sequence: A review of cases in the Philippines from 2000 to 2022

Twin reversed arterial perfusion (TRAP) sequence, or acardiac twinning, is a congenital anomaly associated with monochorionic twin pregnancies. It occurs when the cardiac system of one twin supplies blood for both twins. This congenital anomaly has been previously reported in several case reports from the Philippines. However, there is still limited information about its local epidemiology and management. This study reviewed the previous cases of TRAP sequence and discussed the diagnosis, management, and ways to improve care for pregnant patients affected by this condition. There were five reported cases of TRAP sequence from the Philippines. Ultrasonography was used in diagnosing the disease antenatally. Preterm birth was reported in 60% of the cases, while 80% were delivered via Cesarean section. The most common type of acardiac twinning in the Philippines was the acardius acephalus. The most common placentation observed in TRAP sequence cases was monochorionic, monoamnionic placenta (75%), two of which had arterio-arterial and veno-venous anastomoses. All donor twins in the Philippines were delivered alive, with only one (20%) neonatal death due to Pseudomonas infection. Only a few centers can perform minimally invasive fetal interventions; one center has been performing fetoscopic surgery in the Philippines since 2021. Thus, cases of TRAP sequence in the Philippines have only been managed through antenatal surveillance with serial ultrasound and high-risk prenatal care until their eventual delivery.