Acute intrapartum twin-to-twin transfusion following successful fetoscopic laser ablation

Fetoscopic laser ablation of placental vascular anastomoses is an intrauterine therapy targeting the source of twin-to-twin transfusion syndrome (TTTS). Our patient had successful laser treatment, with resolution of stage II TTTS, suggesting closure of all significant anastomoses. After an uneventful pregnancy course, she elected a trial of labor. Following spontaneous onset of labor, acute intrapartum twin-to-twin transfusion was suspected, suggested by sinusoidal heart rate changes, confirmed post-delivery by twins' complete blood counts. The potential risks of labor with prior fetoscopic laser ablation are reviewed in the context of current knowledge about placental architecture in TTTS.