Treatment and outcome in 370 cases with spontaneous or post-laser twin anemia polycythemia sequence managed in 17 different fetal therapy centers.

OBJECTIVE: to investigate antenatal management and outcome in a large international cohort of spontaneous and post-laser twin anemia polycythemia sequence (TAPS). METHODS: Data of monochorionic twins diagnosed antenatally with TAPS collected in the TAPS Registry between 2014-2019 were included in this study. Antenatal diagnosis of TAPS was based on middle cerebral artery peak systolic velocity (MCA-PSV) > 1.5 Multiples of the Median (MoM) in the TAPS donor and < 1.0 MoM in the TAPS recipient. Cases were assigned to the management groups based on the first treatment that was received. The primary outcome included perinatal mortality and severe neonatal morbidity. The secondary outcome was diagnosis-to-birth interval. RESULTS: In total, 370 TAPS cases were antenatally diagnosed and managed either with expectant management in 31% (113/370), laser surgery in 30% (110/370), intrauterine transfusion (IUT) (with or without partial exchange transfusion (PET)) in 19% (70/370), delivery in 12% (43/370), selective feticide in 8% (30/370) or termination of pregnancy in 1% (4/370). Perinatal mortality occurred in 17% (37/225) of the expectant group, in 18% (38/215) of the laser group, in 18% (25/140) in the IUT (+/- PET) group, in 10% (9/86) in the delivery group and in 7% (2/30) of the co-twins in the selective-feticide group (p = 0.177). Severe neonatal morbidity was 49% (41/84) in delivery, 46% (56/122) in IUT (+/- PET), 31% (60/193) in expectant management, 31% (57/182) in laser surgery and 25% (7/28) in selective feticide (p = 0.027). Median diagnosis-to-birth interval was longest after selective feticide (10.5 weeks; IQR: 4.2-14.9), followed by laser surgery (9.7 weeks, IQR: 6.6-12.7), expectant management (7.8 weeks; IQR: 3.8-14.4), IUT (+/- PET) (4.0 weeks, IQR: 2.0-6.9 weeks) and delivery (0.3 weeks, IQR: 0.0-0.5), p < 0.001. Treatment for TAPS varied greatly within and between the 17 fetal therapy centers. CONCLUSIONS: Antenatal treatment for TAPS differs considerably amongst fetal therapy centers. Perinatal mortality and morbidity were high in all management groups. Prolonging pregnancy was best achieved in expectant management, laser surgery and selective feticide. This article is protected by copyright. All rights reserved.