Twin anaemia polycythaemia sequence

Dr Jeremy Jones and Radswiki et al.

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 twin-to-twin transfusion syndrome cases 2.

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

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 twin-to-twin transfusion syndrome, there is no amniotic fluid discordance (i.e. no-twin oligo-polyhydramnios sequence (TOPS)) 5.

Share article

Article information

rID: 15453
Tag: cases
Synonyms or Alternate Spellings:
  • Twin anaemia-polycythaemia sequence (TAPS)
  • Twin anaemia polycythaemia sequence (TAPS)
  • TAPS

Support Radiopaedia and see fewer ads

Updating… Please wait.

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.