Objective: To explore differences among placental anastomoses, territory discordance, and umbilical cord insertion of twin-to-twin transfusion syndrome (TTTS) with and without selective intrauterine growth restriction (sIUGR).
Methods: This study retrospectively analyzed 57 patients with TTTS who received conservative treatment and finally delivered at the Department of Obstetrics and Gynecology of Peking University Third Hospital from April 2014 to April 2019. Nine of the patient's placentas were too broken to finish the perfusion, and 48 were kept for graph analysis after perfusion. Among the 48 placentas, there were 17 in the TTTS with sIUGR group and 31 in the TTTS without sIUGR group. Differences in the placentas were compared between groups.
Results: The birth weight discordance ratio in the sIUGR group was significantly higher than that in the non-sIUGR group (0.41 ± 0.20 vs 0.24 ± 0.15, p = .001). The prevalence of thick artery-artery (AA) anastomoses in the sIUGR group was significantly higher than that in the non-sIUGR group (35.3% vs 6.5%, p = .017). The placental territory discordance ratio in the sIUGR group was significantly higher than that in the non-sIUGR group (0.40 [0.05, 0.86] vs 0.25 [0.02, 0.67], p = .024). The prevalence of velamentous cord insertion in the sIUGR group was significantly higher than that in the non sIUGR group (35.3% and 6.5%, p = .017).
Conclusions: Placental territory discordance and velamentous umbilical cord insertion may be causes of TTTS with sIUGR. Compared with TTTS without sIUGR, TTTS with sIUGR had a higher prevalence of protective AA anastomoses in the placenta.
Keywords: Monochorionic; anastomosis; placenta; selective intrauterine growth restriction; twin-to-twin transfusion syndrome; vascular.