Twin Anemia Polycythemia Syndrome (TAPS)

Question 1

How do you define TAPS?

Answer 1

Unbalanced blood distribution between twins w/o amniotic fluid discordance; Likely through small (< 1mm) vessels
Unidirectional, unreciprocated artery and vein anastamoses near periphery of placenta

Question 2

How do you screen for TAPS?

Answer 2

MCA PSV> 1.5 MoM in one twin and < 1.0 MoM in the other twin

Question 3

How is TAPS detected?

Answer 3

Typically diagnosed after 26 weeks, most commonly after laser (13%) than spontaneous (3-5%)

I - MCA PSV > 1.5 MoM and < 1.0 MoM, no compromise
II - MCA PSV > 1.7 MoM and < 0.8 MoM, no compromise
III - Stage I OR II and cardiac compromise (critically abnormal Dopplers)
IV - Hydrops of donor
V - Demise of one or both fetuses preceded by TAPS

Question 4

What is the likelihood of developing TAPS in a mo/di twin gestation?

Answer 4

3-5%

Question 5

What is the likelihood of developing TAPS following laser surgery for TTTS?

Answer 5

Up to 16%

Question 6

If TAPS is detected, how will you manage the patient?

Answer 6

Expectant management, delivery (stage I), selective feticide, IUT (may be short duration, may worsen polycythemia hyperviscosity syndrome in the recipient, skin necrosis of LE reported)-donor IV vs IP, partial exchange IUT or laser photocoagulation