Category: Fetus
Poster Session II
Fetoscopic laser ablation of vascular connections between monochorionic twins with twin-twin transfusion syndrome (TTTS) has dramatically improved outcomes, but appears associated with increased preterm prelabor rupture of membranes (PPROM). Studies attempting to determine the technical factors that contribute to iatrogenic PPROM have shown mixed results and identified no consensus risk factors. Our objective was to determine procedural factors associated with PPROM in a moderately sized cohort.
Study Design:
This is a retrospective cohort study of fetoscopic laser ablation cases performed at a single center between 2011-2020. PPROM was diagnosed any time following fetoscopic intervention through 35w6d, as institutional protocol triggered delivery for TTTS between 35w0d and 35w6d. Factors assessed included gestational age at intervention, type of laser procedure, placental location, number of anastomoses, net amnioreduction volume, cannula insertion site, cannula size, laser energy and time, and procedure time. Goal of amnioreduction was deepest vertical pocket of 6-8cm. Statistical analysis included chi-square and t-test.
Results:
There were 77 procedures performed and data regarding timing of membrane rupture was available for 71. The overall rate of PPROM was 32% (n=23). Of the procedural variables examined, only net amnioreduction volume was different between groups (p=.004) (Table 2). In the PPROM group, 7 (30%) patients had no net amnioreduction versus 3 (6%) in the no PPROM group (odds ratio [OR] 5.8 [95% CI 1.3-25.8]). Additionally, 8 (17%) patients who did not develop PPROM had amnioreduction >2L compared to none in the PPROM group (OR 0.59 [95% CI 0.47-0.74]).
Conclusion:
Our findings are largely consistent with prior literature which has demonstrated no relationship between a number of procedural factors and iatrogenic PPROM following fetoscopic laser ablation for TTTS. However, it does appear that concurrent amnioreduction may provide a protective effect against iatrogenic PPROM, and this is a novel finding. It may be that by reducing amniotic fluid volume, tension on the membranes is relieved, and thus risk of PPROM is decreased.
Alexandra J.D Phelps, MD (she/her/hers)
Maternal-Fetal Medicine Fellow
Vanderbilt University Medical Center
Nashville, Tennessee, United States
Calla Holmgren, MD
Advocate Lutheran General Hospital
Park Ridge, Illinois, United States
Diamond Ling, MD
Adventist Shady Grove Medical Center
Rockville, Maryland, United States
Tabitha Tate, MD
University of Minnesota Division of Neonatology
Minneapolis, Minnesota, United States
Preetha Prazad, MD
Advocate Children's Medical Group
Barrington, Illinois, United States
Suwan Mehra, MD
Advocate Lutheran General Hospital
Park Ridge, Illinois, United States