Laser therapy for twin-twin transfusion syndrome in the absence of fetoscopically visible placental vascular anastomoses.

Fetoscopic laser photocoagulation (FLP) was performed at 22 weeks of gestation for a pregnancy complicated with twin-twin transfusion syndrome (TTTS) and an anterior placenta. However, vascular anastomoses could not be identified by the fetoscope. To dichotomize the circulation between the twins, the terminal ends of the paired artery and vein of the recipient twin were coagulated. In addition, a line was drawn with the laser connecting the dots, which had been coagulated. The Doppler waveform as well as the amniotic fluid volume of each twin normalized after the procedure. The twins were delivered by cesarean section subsequent to onset of labor at gestational week 30; the recipient twin weighed 1,350 g and the donor twin weighed 550 g. Both twins had a normal neurologic exam at 6 months of age. Patent placental vascular anastomoses could not be detected. This case demonstrates that vascular anastomoses in TTTS may not be identified by a fetoscope and that FLP to coagulate the entire vascular equator closer to the area of the recipient twin was effective in this rare situation.