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CME Credit Offered
CME Credit Offered
Abstract Award
Abstract Award
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Poster Session 3

(828) Postlaser persistent polyhydramnios after resolution of Twin to Twin Transfusion Syndrome

Friday, January 31, 2025
10:30 AM – 12:30 PM  
Objective: Fluid abnormalities should resolve after fetoscopic laser surgery (FLS) for Twin to Twin Transfusion Syndrome (TTTS), but polyhydramnios occasionally persists. We sought to compare patients with persistent polyhydramnios (PP) to those with resolved polyhydramnios (RP) after FLS for TTTS.

Study Design: Single-center retrospective review of monochorionic twins who underwent FLS for TTTS from 6/2014 to 1/2024. Patients with PP had a maximum vertical pocket (MVP) > 8 cm in the former TTTS recipient  > 14 days after laser. RP patients had resolution of polyhydramnios < 14 days after laser. High order multiples and those with TTTS recurrence were excluded. Pre-treatment characteristics and birth outcomes were compared between PP and RP groups via Pearson or Fischer’s Exact Chi Squared and Mann-Whitney U. ROC analysis was performed to explore the relationship between pre-laser MVP and PP.

Results:

377/405 (93%) patients had RP after laser and 28 (7%) patients had PP (Figure 1). PP recipients had higher prelaser MVP (11.3 vs 10.1 cm, p=0.013), higher amnioreduction volumes (1900 vs 1500 cc, p=0.034) and higher post operative day 1 MVPs (7.4 vs 6.0 cc, p=0.010) (Table 1). An ROC analysis demonstrated that a prelaser recipient MVP of 11.0 cm predicted PP with 64% sensitivity and 64% specificity. Model quality Gini Index 0.53, area under the curve 0.64 (95% CI: 0.538-0.753), p=0.014. Remaining pre-treatment and intraoperative findings were not different between groups, though there was a trend towards more pyelectasis in PP recipients (10.7 vs 2.7%, p=0.053). Average time to resolution of polyhydramnios was 35 days in the PP group, versus 3 days in RP (p< 0.001), and was documented in 95% of cases. Gestational age at delivery, birth survival, and birthweight discordance were not different between groups.

Conclusion:

Persistent polyhydramnios occurred in 7% of patients after laser for TTTS, but ultimately resolved in 95% and was not associated with adverse obstetric outcomes. A trend towards more pyelectasis in PP recipients suggests persistent polyuria as a potential etiology of PP.