Risks of single fetal demise after laser for Twin-Twin Transfusion Syndrome

Introduction: To determine if markers of donor placental insufficiency and recipient cardiac dysfunction increase the risk for single fetal demise (SFD) after laser for Twin-Twin Transfusion Syndrome (TTTS).Methods: Single center retrospective review of patients who had laser for TTTS. Risk factors for donor and recipient demise within one week were compared in pregnancies with SFD and pregnancies with dual survival using Chi square or Fisher's exact test. Multivariate logistic regression was then performed. Results: Of 398 procedures, 305 (76.6%) had dual survival, 36 (9.0%) had donor demise, 28 (7.0%) had recipient demise and 9 (2.3%) had dual demise. The remaining 20 (5.0%) patients had complicated courses with pregnancy loss or further intervention. In the 64 pregnancies with SFD, 29 (81%) in the donor group and 20 (71%) in the recipient group occurred in the first postoperative week. For the donor demise group, estimated fetal weight (EFW) < 10%, EFW < 3%, EFW < 1%, EFW discordance > 25%, and EFW discordance > 30% did not increase the risk for donor demise except in cases that also had umbilical artery absent or reversed end diastolic flow (AREDF). Donor AREDF was the only independent risk factor for early donor demise. For the recipient demise group, recipient abnormal venous Dopplers were associated with increased risk while EFW discordance > 25% was associated with decreased risk of recipient loss. Discussion/Conclusion: In our cohort, donor growth restriction did not increase the risk of early donor demise after laser unless there was also donor AREDF. Donor AREDF was an independent risk factor for donor demise likely due to the severity of placental insufficiency. Abnormal recipient venous Doppler indices increased the risk of early recipient loss while a large intertwin discordance decreased the risk. This may be explained by profound overload in cases with recipient abnormal venous Doppler velocimetry and a lower risk of substantial fluid shifts from a relatively smaller donor territory when there is a large discordance.