Twin anemia polycythemia sequence after fetoscopy: predictors of development

Objective. To identify predictors of post-fetoscopic twin anemia polycythemia sequence (pTAPS) after fetoscopic laser photocoagulation (FLP) of placental anastomoses for twin–twin transfusion syndrome (TTTS). Patients and methods. The study included 195 patients who underwent FLP of anastomoses for TTTS during the period from 2010 to September 2019. A group of 13 pregnant women in whom pTAPS developed in the postoperative period was selected. Results. Out of 169 pregnancies lasting for more than 2 weeks after FLP of anastomoses, pTAPS developed in 13 (7.7%). It was revealed that FLP was performed before 20 weeks in 85% of those who developed pTAPS, while the average period in the group was 22.1 weeks. Localization of the placenta along the anterior wall of the uterus with pTAPS was observed 3 times more often than along the posterior wall, while in the rest of the operated patients this ratio was approximately 1:1. The number of anastomoses ranged from 3 to 11, most frequently – 5. Conclusion. With the development of pTAPS, there is a high probability of an unfavorable outcome. Localization of the placenta along the anterior wall of the uterus, localization of the anastomoses in the amniotic cavity of the donor twin are the factors that predispose to the development of pTAPS. The presence of 1–2 large AV anastomoses together with no more than 5 small anastomoses may serve as a probable predictor of the pTAPS development. Key words: multiple pregnancy, twin anemia polycythemia sequence, twin-twin transusion syndrome, fetoscopy