Longitudinal Observation of Twin-to-Twin Transfusion Syndrome, Twin Anemia-Polycythemia Sequence, and Selective Fetal Growth Restriction with Spontaneous Attenuation and Progressive Donor Twin Brain Injury: A Case Report.

A 34-year-old woman with a monochorionic diamniotic twin pregnancy developed twin-to-twin transfusion syndrome and selective fetal growth restriction at 21 weeks, followed by the onset of twin anemia-polycythemia sequence at 23 weeks. Fetoscopic laser photocoagulation could not be performed. Therefore, the pregnancy was managed expectantly. By 24-26 weeks, amniotic fluid levels and cerebral Doppler parameters normalized, but the donor twin's cardiac function deteriorated progressively. At 26 weeks, neurosonography showed diffuse periventricular hyperechogenicity, followed by ventriculomegaly at 28 weeks. Cesarean delivery was performed at 34 weeks because of preeclampsia. The donor twin was severely anemic, showed cerebral atrophy, and died on day 6. The recipient remained stable. This case illustrates the natural progression and dynamic interplay of three clinical conditions, resulting in hypoxic-ischemic brain injury in the donor twin. Our findings indicate the importance of cardiovascular monitoring to understand the complex pathophysiology in such pregnancies.