(1216) Management and Outcomes of Spontaneous Twin Anemia Polycythemia Sequence (TAPS)

Optimal antenatal management of spontaneous twin anemia-polycythemia sequence (TAPS) remains uncertain. We reviewed management and outcomes at a single center.

Study Design:
We conducted a retrospective cohort study of monochorionic diamniotic twins diagnosed with spontaneous TAPS (delta MCA-PSV ≥ 0.5) between 2019–2025. Management included selective feticide, expectant management, intrauterine transfusion (IUT) ± partial exchange transfusion (PET), laser therapy, laser + transfusion, and delivery. The primary outcome was obstetric complications. The secondary outcome was diagnosis-to-birth interval.

Results:

Eighteen pregnancies met inclusion, with 94% (n=17) Stage II or greater, and 17% (n=3) with concomitant Stage II-III twin-to-twin transfusion syndrome (TTTS). Initial management included laser (39%, n=7), IUT± PET (33%, n=6), expectant (11%, n=2), selective feticide, laser+ IUT, or delivery (each 6%, n=1). Median gestational age at diagnosis was 22w3d. Obstetric complications included worsening TAPS and/or development of other monochorionic pathology (56%, n=10), IUFD of one twin (11%, n=18), PPROM, placental abruption and delivery for non-reassuring fetal status (each 6%, n=1). Median (IQR) diagnosis-to-birth interval was 43 days (20–98). The interval was 143 days for selective feticide, 98 for laser (78–102), 81 for expectant management (58–104), 15 for IUT±PET (6–34), and 22 for laser + transfusion. After adjusting for GA at diagnosis, the median interval was 11.3 weeks longer with laser than IUT±PET (p=0.009). When excluding those with concomitant TTTS, the interval remained greater than IUT±PET (6 weeks) but was not statistically significant (p=0.25). Overall survival to discharge in this cohort was 94% (33/35).

Conclusion:

Laser yielded the longest diagnosis-to-birth interval among non-feticide options, though accounted for the only unintended fetal losses. Progression of TAPS or emergent monochorionic pathology was the leading complication, primarily after IUT±PET. Given small sample sizes, larger multicenter studies are needed to determine optimal management of spontaneous TAPS.