(620) Expectant Management versus. Prompt Laser Therapy for Stage II Twin-Twin-Transfusion-Syndrome before 18 weeks

Objective: In some reports, fetoscopy before 18 weeks (wks) gestational age (GA) is associated with a greater risk of poor perinatal outcomes. We assessed efficacy of expectant management (EM) followed by fetoscopic placental laser ablation (FLA) at 18 wks versus prompt intervention (PI) in patients with early-Stage II twin-to-twin transfusion syndrome (TTTS).

Study Design: This is a secondary analysis of prospectively collected data from monochorionic diamniotic (MCDA) pregnancies with Stage 2 TTTS prior to 18 wks GA at two fetal centers. We compared outcomes between patients that had FLA promptly after evaluation (PI) to those where expectant management (EM), with twice-weekly surveillance and intent to perform FLA at 18 wks GA, was undertaken.  For the EM group, we assessed incidence of early FLA (i.e., < 18 wks) for progressive polyhydramnios or worsening severity of disease (i.e., upstaging). Ultrasound characteristics, GA of delivery, incidence and timing of preterm prelabor rupture of membranes (PPROM) and survival were compared between groups.

Results: Stage 2 TTTS prior to 18 wks was confirmed in 54 MCDA pregnancies with 18 (33.3%) in the EM group and 36 (66.7%) in the PI group. In the EM group, 12 patients had FLA at 18 weeks, while 6 had early FLA (Figure). The PI group presented 3.5 days later than the EM group (p = 0.02), while time between evaluation and PLA was greater in the EM group (6 vs. 1 days, p < 0.01). Ultrasound characteristics between the groups were similar (Table). Rates of PPROM were similar between groups. However, the GA of PPROM trended later in the EM group (24.8 vs. 19.6 wks, p = 0.08) while the FLA to PPROM interval trended longer (6.7 v. 3.3 days, p = 0.31). GA at delivery was similar between groups. Dual survival rates were 88.9% and 75.0% (p = 0.30) in the EM and PI groups respectively. In the EM group, dual survival occurred in all upstaged cases.

Conclusion: Expectant management for early Stage II TTTS was noninferior to prompt intervention. The timing of PPROM, when it occurs, may be more favorable with EM, however further study is required to assess this possibility.