Twin reversed arterial perfusion

<p>Twin reversed arterial perfusion sequence, also called TRAP sequence, TRAPS, or acardiac twinning, is a rare complication of <a href="/facts/Monochorionic/hDGmrGdx">monochorionic</a> twin pregnancies. It is a severe variant of <a href="/facts/Twin-to-twin_transfusion_syndrome/bryytamS">twin-to-twin transfusion syndrome</a> (TTTS). In addition to the twins' blood systems being connected instead of independent, one twin, called the acardiac twin, TRAP fetus or acardius, is severely malformed. The heart is absent or deformed, hence the name "acardiac", as are the upper structures of the body. The other limbs may be partially present or missing, and internal structures of the torso are often poorly formed. The other twin is usually normal in appearance. The normal twin, called the pump twin, drives blood through both fetuses. It is called "reversed arterial perfusion" because in the acardiac twin the blood flows in a reversed direction.
</p><p>TRAP sequence occurs in 1% of monochorionic twin pregnancies and 1 in 35,000 pregnancies overall.
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Twin reversed arterial perfusion open-in-new

Twin reversed arterial perfusion