In utero Partial Exchange Transfusion Combined with in utero Blood Transfusion for Prenatal Management of Twin Anemia-Polycythemia Sequence.

Monochorionic twin pregnancies are at risk of unique complications due to placental sharing and vascular connections between placental territories assigned for each twin. Twin anemia-polycythemia sequence (TAPS) is an infrequent but potentially dangerous complication of abnormal placental vascular connections. TAPS occurs due to very-small-caliber (< 1 mm) abnormal placental vascular connections which lead to chronic anemia in the donor twin and polycythemia in the recipient twin. TAPS may occur spontaneously or following fetoscopic laser photocoagulation of communicating placental vessels for twin-twin transfusion syndrome. One of the hallmarks of TAPS is the absence of polyhydramnios and oligohydramnios. The postnatal diagnosis is based on significant hemoglobin discrepancy between the twins. Middle cerebral artery peak systolic velocity Doppler ultrasound allows for the prenatal diagnosis of TAPS. The optimal prenatal treatment and intervention timing has not been established. Here, we report 3 spontaneous TAPS cases diagnosed and managed in the prenatal period with a combination of in utero blood transfusion for the anemic twin (donor) and in utero partial exchange transfusion for the polycythemic twin (recipient). These cases contribute to the limited outcome data of this underutilized method for the management of TAPS.