Abstract:

Objective

To explore the prenatal ultrasound features and prognosis of twin anemiapolycythemia sequence (TAPS).

Methods

A retrospective analysis was conducted on 26 twins diagnosed with TAPS by prenatal ultrasound at the Women and Children’s Hospital of Chongqing Medical University from July 2017 to December 2024, focusing on their prenatal ultrasound features, treatment methods, and pregnancy outcomes.

Results

All 26 cases were monochorionic twins, and all were diagnosed with primary TAPS.Common prenatal ultrasound features included: (1) peak systolic velocity of the middle cerebral artery (MCA-PSV) > 1.5 multiples of the median (MoM) in the donor twin and < 1.0 MoM in the recipient twin; and (2) “black and white” placenta.Other ultrasound features included: (1) “starry sky” sign in the recipient twin’s liver; (2) enhanced intestinal echogenicity in the donor twin; (3) cardiac abnormalities;(4) abnormal Doppler blood flow indices; (5) fetal hydrops; (6) umbilical cord abnormalities; (7) uneven amniotic fluid volume; and (8) coexisting selective intrauterine growth restriction, twin to twin transfusion syndrome, etc.Among the 26 cases, 13 underwent radiofrequency ablation for fetal reduction (survival rate 92%), 5 underwent fetoscopic coagulation of placental vascular anastomoses (survival rate 100%), 7 received expectant management (survival rate 64%), and 1 underwent induced labor.

Conclusion

In ultrasound examinations of monochorionic twins, special attention should be paid to fetal Doppler blood flow indicators,placental conditions, liver and intestinal tract echoes, etc.The prognosis of TAPS twins without intrauterine treatment is relatively poor.Once TAPS is diagnosed, it is recommended to refer the patient to a tertiary prenatal diagnosis center with intrauterine treatment conditions for diagnosis and treatment.

Key words: Monochorionic twins, Twin anemia-polycythemia sequence, Prenatal ultrasound, Intrauterine treatment