Twin anemia-polycythemia sequence

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Twin anemia-polycythemia sequence
Synonyms	TAPS
Pronounce	N/A
Specialty	N/A
Symptoms	Anemia in one twin, Polycythemia in the other
Complications	Heart failure, Hydrops fetalis, Intrauterine growth restriction
Onset	Prenatal
Duration	Until birth, may require postnatal treatment
Types	Spontaneous, Post-laser
Causes	Unequal blood flow through placental anastomoses
Risks	Monochorionic twins
Diagnosis	Doppler ultrasound, Middle cerebral artery peak systolic velocity
Differential diagnosis	Twin-to-twin transfusion syndrome
Prevention	Monitoring of monochorionic pregnancies
Treatment	Intrauterine transfusion, Partial exchange transfusion
Medication	N/A
Prognosis	Variable, depends on severity and treatment
Frequency	3-5% of monochorionic twin pregnancies
Deaths	N/A

Twin Anemia-Polycythemia Sequence (TAPS) is a rare condition that can occur in monochorionic twins, where the twins share a single placenta. It is characterized by a significant difference in the hemoglobin levels between the twins, leading to one twin becoming anemic and the other polycythemic.

Pathophysiology

TAPS is caused by very small vascular connections in the placenta, which allow blood to flow from one twin to the other. Unlike twin-to-twin transfusion syndrome (TTTS), which involves larger blood vessel connections, TAPS involves minuscule connections that result in a slow, chronic transfusion of blood from the donor twin to the recipient twin. This results in the donor twin developing anemia and the recipient twin developing polycythemia.

Diagnosis

TAPS is typically diagnosed through ultrasound and Doppler studies, which can detect differences in the blood flow velocities in the middle cerebral artery of the twins. The condition can also be diagnosed postnatally by measuring the hemoglobin levels of the twins.

Treatment

The management of TAPS depends on the severity of the condition and the gestational age at diagnosis. Options include close monitoring, intrauterine transfusion for the anemic twin, and early delivery if necessary. In some cases, laser surgery may be performed to close the small vascular connections in the placenta.

Prognosis

The prognosis for twins affected by TAPS varies. Early detection and treatment can improve outcomes, but the condition can lead to complications such as neurological damage or fetal demise if not managed appropriately.

See Also

• Twin-to-twin transfusion syndrome
• Monochorionic twins
• Polycythemia
• Anemia