Twin anaemia polycythaemia sequence

Dr Henry Knipe and Radswiki et al.

The twin anaemia polycythaemia sequence (TAPS) is considered a variant of the twin to twin transfusion syndrome (TTTS).

TAPS may occur spontaneously in up to 5% of monochorionic twins and may also develop after incomplete laser treatment in TTTS cases 2.

As with TTTS the underlying mechanism is thought to be abnormal placental vascular anastomoses. One twin develops an anaemia and the other polycythaemia.

Antenatal ultrasound

One of the features suggesting towards the diagnosis is a discordance in fetal middle cerebral artery peak systolic velocity (MCA-PSV) measurements 4. In contrast to the classic TTTS there is no amniotic fluid discordance (i.e. no twin oligo-polyhydramnios sequence (TOPS)) 5.

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Article Information

rID: 15453
Section: Pathology
Tags: cases, snippet
Synonyms or Alternate Spellings:
  • Twin anaemia-polycythaemia sequence (TAPS)
  • Twin anaemia polycythaemia sequence (TAPS)
  • TAPS

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