(974) Complications of fetoscopic laser surgery across gestational ages

Data conflict on whether fetoscopic laser surgery (FLS) for twin-to-twin transfusion syndrome (TTTS) has higher rates of morbidity and mortality when performed earlier in gestation. We sought to estimate complication rates across gestational ages (GA).

Study Design: This is a secondary analysis of prospectively collected data on all patients with monochorionic diamniotic twins with TTTS that underwent FLS between 2011 and 2022 at a single center. Patients were divided into 2-week epochs by GA of FLS. Demographic, ultrasound, and operative characteristics were compared across epochs. Rates of preterm premature rupture of membranes < 34 wks (PPROM), GA of delivery, overall survival and days of maternal hospitalization were compared across epochs. Latency following PPROM was also compared using Kaplan-Mejer curves.

Results:

555 patients underwent FLS for TTTS during the study period. Stage III disease was more common at 16 – 20 wks GA (Table, p < 0.01). Cervical length was also shorter at greater GA (p < 0.01) and larger (i.e. 12 Fr) operative cannulas were more commonly used (p < 0.01). The rates of PPROM < 1 wk from FLS and overall PPROM were higher in the 16 – 18 week epoch (A, p < 0.01). However, GA of delivery was similar across all epochs (B, p = 0.71) even when considering only cases with PPROM (C, p = 0.80). Latency periods following PPROM were inversely proportional to GA at FLS (D, p < 0.01). There were no differences in the total time of maternal hospitalization (mean = 8.35 days, p = 0.31). Survival across all gestational ages was similar, however dual survival was lower for FLS performed at 16 – 18 wks compared to all other epochs (61.1% vs. 79.2%, p < 0.01).

Conclusion:

FLS prior to 18 weeks is associated with greater rates of PPROM, but with similar GA at delivery and longer latency when PPROM does occur. Lower survival at 16 – 18 weeks is likely associated with greater incidence of advanced disease, not PPROM and earlier delivery. Hesitancy in performing FLS at 16 – 18 wks GA may not be warranted.