TRAP sequence
Pronunciation: trap SEE-kwens
Also written as: TRAP — Twin Reversed Arterial Perfusion
Twin reversed arterial perfusion sequence, a rare complication of monochorionic twin pregnancies where one twin lacks a functional heart.
Full Definition
TRAP sequence (Twin Reversed Arterial Perfusion) is a rare and serious complication occurring exclusively in monochorionic twin pregnancies, affecting approximately 1% of such pregnancies. In this condition, one twin (the acardiac or TRAP twin) lacks a functional heart and is perfused by the other twin (the pump twin) through arterio-arterial and veno-venous anastomoses. The acardiac twin typically has severe malformations and acts as a parasitic twin, placing significant strain on the pump twin's cardiovascular system. Treatment options include selective reduction procedures such as radiofrequency ablation or cord occlusion to prevent cardiac failure in the pump twin.
Usage
Usage note: Acronym should be written in all caps; distinguish from TTTS which involves different pathophysiology.
In Context
- "Doppler studies confirmed TRAP sequence with reversed flow in the acardiac twin." — Maternal-fetal medicine consultation
- "Urgent intervention was planned to prevent cardiac decompensation in the pump twin due to TRAP sequence." — Surgical planning note