Twin reversed arterial perfusion: Difference between revisions

Latest revision as of 00:47, 18 February 2025

A rare complication of monochorionic twin pregnancies

Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic twin pregnancies, where one twin, known as the "acardiac twin," is severely malformed and lacks a functioning heart. The other twin, referred to as the "pump twin," provides circulation for both twins, leading to significant health risks.

Pathophysiology[edit]

In TRAP sequence, the acardiac twin receives blood from the pump twin through abnormal arterial anastomoses in the placenta. This reversed blood flow results in the acardiac twin developing without a heart and often without a head, leading to severe malformations. The pump twin is at risk of heart failure due to the increased cardiac workload.

Diagnosis[edit]

TRAP sequence is typically diagnosed through ultrasound imaging, which reveals the presence of an acardiac twin. The acardiac twin may appear as a mass with no cardiac activity, and the pump twin may show signs of hydrops fetalis if heart failure is developing.

Management[edit]

Management of TRAP sequence focuses on monitoring the pump twin and may involve interventions to reduce the cardiac load on the pump twin. Options include radiofrequency ablation or laser coagulation of the vessels supplying the acardiac twin. In some cases, early delivery may be necessary.

Prognosis[edit]

The prognosis for the pump twin depends on the size of the acardiac twin and the degree of cardiac strain. Early detection and intervention can improve outcomes, but the condition remains high-risk.

Related pages[edit]

References[edit]

Hecher, K., et al. (2001). "Twin reversed arterial perfusion: A systematic review of literature." Prenatal Diagnosis, 21(8), 693-699.
Lewi, L., et al. (2010). "The outcome of twin reversed arterial perfusion sequence diagnosed in the first trimester." American Journal of Obstetrics and Gynecology, 203(3), 213.e1-213.e4.

Acardiac twin
Acephalus Boulgakow

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-'''Twin Reversed Arterial Perfusion''' (TRAP) sequence is a rare complication of monochorionic twin pregnancies, where one twin (the "pump twin") provides circulatory support to the other twin (the "acardiac twin"), which lacks a functional heart. This condition is also known as '''acardiac twinning''' and is a form of [[Twin-to-Twin Transfusion Syndrome]] (TTTS), although it presents uniquely due to the acardiac twin's reliance on the pump twin for blood circulation.
+{{Short description|A rare complication of monochorionic twin pregnancies}}
+{{Use dmy dates|date=October 2023}}
-==Etiology==
+'''Twin reversed arterial perfusion''' ('''TRAP''') sequence is a rare complication of [[monochorionic twin]] pregnancies, where one twin, known as the "acardiac twin," is severely malformed and lacks a functioning heart. The other twin, referred to as the "pump twin," provides circulation for both twins, leading to significant health risks.
-The exact cause of TRAP sequence is not fully understood, but it is believed to result from abnormal placental vascular connections that allow arterial blood from the pump twin to flow into the acardiac twin. This reversed flow leads to the development of an acardiac fetus, which typically lacks a fully formed heart and other upper body structures, depending on the severity of the condition.
 ==Pathophysiology==
-In TRAP sequence, the pump twin's heart works harder to support both fetuses, leading to potential heart failure and other complications such as [[Polyhydramnios]] and [[Hydrops Fetalis]]. The acardiac twin, on the other hand, may develop a range of malformations, often being partially or completely missing the upper body, including the heart, hence the term "acardiac."
+In TRAP sequence, the acardiac twin receives blood from the pump twin through abnormal [[arterial anastomoses]] in the placenta. This reversed blood flow results in the acardiac twin developing without a heart and often without a head, leading to severe malformations. The pump twin is at risk of [[heart failure]] due to the increased cardiac workload.
 ==Diagnosis==
-Diagnosis of TRAP sequence is usually made through [[Ultrasound]] imaging during pregnancy. Key indicators include the presence of a monochorionic twin pregnancy, identification of one twin with severe malformations and lack of a functional heart, and the observation of reversed arterial blood flow from the healthy twin to the malformed twin.
+TRAP sequence is typically diagnosed through [[ultrasound]] imaging, which reveals the presence of an acardiac twin. The acardiac twin may appear as a mass with no cardiac activity, and the pump twin may show signs of [[hydrops fetalis]] if heart failure is developing.
 ==Management==
-Management of TRAP sequence aims to reduce the risks to the pump twin while considering the viability of the pregnancy. Options include careful monitoring, [[Amnioreduction]] to manage polyhydramnios, and in some cases, fetal intervention. Fetal intervention may involve procedures such as radiofrequency ablation (RFA) or laser coagulation to disrupt the blood flow to the acardiac twin, thereby reducing the burden on the pump twin's heart.
+Management of TRAP sequence focuses on monitoring the pump twin and may involve interventions to reduce the cardiac load on the pump twin. Options include [[radiofrequency ablation]] or [[laser coagulation]] of the vessels supplying the acardiac twin. In some cases, early delivery may be necessary.
 ==Prognosis==
-The prognosis for TRAP sequence varies depending on the severity of the condition and the timing and effectiveness of treatment. The pump twin has a higher risk of morbidity and mortality, primarily due to heart failure and the complications of prematurity. With appropriate management, however, the survival rate of the pump twin can be significantly improved.
+The prognosis for the pump twin depends on the size of the acardiac twin and the degree of cardiac strain. Early detection and intervention can improve outcomes, but the condition remains high-risk.
-==Epidemiology==
+==Related pages==
-TRAP sequence is a rare condition, occurring in approximately 1% of monochorionic twin pregnancies and 1 in 35,000 pregnancies overall. It is more common in pregnancies resulting from assisted reproductive technologies.
+* [[Monochorionic twins]]
+* [[Twin-to-twin transfusion syndrome]]
-==See Also==
+==References==
-* [[Twin-to-Twin Transfusion Syndrome]]
+* Hecher, K., et al. (2001). "Twin reversed arterial perfusion: A systematic review of literature." ''Prenatal Diagnosis'', 21(8), 693-699.
-* [[Monochorionic Twins]]
+* Lewi, L., et al. (2010). "The outcome of twin reversed arterial perfusion sequence diagnosed in the first trimester." ''American Journal of Obstetrics and Gynecology'', 203(3), 213.e1-213.e4.
-* [[Polyhydramnios]]
-* [[Hydrops Fetalis]]
-[[Category:Obstetrics]]
+[[Category:Complications of pregnancy]]
-[[Category:Pediatrics]]
+[[Category:Twin studies]]
-[[Category:Congenital Disorders]]
-{{Medicine-stub}}
+[[File:Acardiac_twin.jpg|thumb|An ultrasound image showing an acardiac twin.]]
+[[File:Acephalus_Boulgakow_1.jpg|thumb|A historical depiction of an acardiac twin.]]
+<gallery>
+File:Acardiac_twin.jpg|Acardiac twin
+File:Acephalus_Boulgakow_1.jpg|Acephalus Boulgakow
+</gallery>