Mackenzie Simon-Collins, Camille Shantz, Rachana Tanksali, Maryn Day, Julie Alan, Sarah Millard, Michelle Kush, Jena Miller, Ahmet Baschat, Mara Rosner
PP occurred in 5.7% of patients after FLS for TTTS. Resolution of PP occurred in 94.4% of PP patients in a median of 28 days and was not associated with adverse obstetric outcomes. The trend of increased incidence of recipient pyelectasis suggests delayed resolution of recipient polyuria as a potential etiology of PP.
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.
METHODS: Single-center retrospective review of monochorionic twins who underwent FLS for TTTS from June 2014 to January 2024. Patients with RP had resolution of polyhydramnios ≤ 14 days after FLS. PP patients had a maximum vertical pocket (MVP) ≥ 8 cm in the former TTTS recipient > 14 days after FLS. Patients with septostomy, global membrane separation, membrane rupture within 2 weeks of laser, early recipient demise ≤ 14 days after FLS, TTTS recurrence, or undergoing repeat FLS were excluded. Pretreatment characteristics and birth outcomes were compared between PP and RP groups via Pearson or Fischer's exact chi-squared and Mann-Whitney U test. We chose gestational age (GA) at delivery as our primary outcome.
RESULTS: A total of 317 out of 336 (94.3%) patients had RP after FLS, and 19 (5.7%) patients had PP. PP recipients had higher pre-FLS MVP (12.5 vs. 10.0 cm, p = 0.003), higher amnioreduction volumes (2000 vs. 1500 mL, p = 0.030), and higher postoperative day 1 MVPs (7.0 vs. 6.0 cm, p = 0.009). There was a trend toward a higher rate of preoperative recipient pyelectasis in patients with PP (p = 0.069). Average time to resolution of polyhydramnios was 2 days in RP group versus 28 days in the PP group (p < 0.001). Polyhydramnios resolved in 17/18 (94.4%) of PP cases with available outcomes. GAs at delivery, birth survival, and birthweight discordance were not different between groups.
CONCLUSION: PP occurred in 5.7% of patients after FLS for TTTS. Resolution of PP occurred in 94.4% of PP patients in a median of 28 days and was not associated with adverse obstetric outcomes. The trend of increased incidence of recipient pyelectasis suggests delayed resolution of recipient polyuria as a potential etiology of PP.