(412) Gestational age-related risk of rupture of membranes in the setting of fetoscopy for twins

Thursday, February 9, 2023

4:00 PM – 5:30 PM

Objective: To describe, in twin pregnancies, the gestational age-related risk of postoperative rupture of membranes (ROM) < 34 weeks when fetoscopic surgery occurs from 16-26 weeks.

Study Design: Retrospective cohort study of twin pregnancies that underwent fetoscopy at a single fetal center from April 2010 to June 2019. Inclusion criteria was any twin pregnancy in which fetoscopic surgery was performed between 16-26 weeks. Exclusion criteria was aneuploidy, major congenital anomalies, higher order multiples. This study received IRB approval. Pregnancies were stratified by the week of fetoscopy. Primary outcome was the risk of ROM < 34 weeks gestation. Given that earlier surgery carries a longer latency between surgery and 34 weeks, to further measure the risk of ROM, Logrank analysis was used to evaluate the probability of having intact fetal membranes in the 8 weeks immediately post-op. For this analysis, surgeries were grouped into 3 gestational age ranges: surgery < 20 weeks, surgery from 20 0/7-22 6/7 weeks, and surgery from 23-25 6/7 weeks.

Results: 696 pregnancies met inclusion. 221 (32%) experienced ROM < 34 weeks. 118 (17%) experienced ROM within 8 weeks of fetoscopy. The risk of ROM with each week of gestation, as well as the 95% CI estimates are listed in table 1. There was a statistically significant decrease in ROM prior to 34 weeks when surgery occurred beyond 20 weeks gestation. Evaluating the probability of pregnancies having continued intact membranes in the 8 weeks immediately post-op revealed an intact membrane rate of 78% (95% CI 72-82%) when surgery occurred < 20 weeks, 87% (95% CI 82-90%) when surgery occurred between 20-22 6/7 weeks, and 79% (95% CI 71-85%) when surgery occurred between 23-25 6/7 weeks (p < 0.001), figure 1.

Conclusion: The risk of ROM < 34 weeks decreases when fetoscopy occurs after 20 weeks. Compared to < 20 weeks, there is a lower risk of ROM in the subsequent 8 weeks when surgery occurs between 20-22 6/7 weeks. Interestingly, when surgery occurred < 20 weeks compared to 23-25 6/7 weeks, there was no difference in the risk of ROM in the 8 weeks immediately post-op.

Primary & Presenting Author(s)

Braxton Forde, MD
Assistant Professor
Division of Maternal-Fetal Medicine, University of Cincinnati Medical Center
Cincinnati, Ohio, United States

Coauthor(s)

FL
Foong Lim, MD
Cincinnati Children's Hospital Medical Center
Cincinnati, Ohio, United States
JP
Jose Peiro, MD
Professor Surgery - Director Fetal Care Center
Cincinnati Children's Hospital Medical Center
Cincinnati, Ohio, United States
DM
David McKinney, MD
University of Cincinnati Medical Center
Cincinnati, Ohio, United States
KM
Kara B. Markham, MD
Associate professor MFM
University of Cincinnati
Cincinnati, Ohio, United States
MH
Mallory Hoffman, MD
Tristate Maternal Fetal Medicine
Cincinnati, Ohio, United States
MH
Mounira Habli, MD
Maternal-Fetal Medicine, Good Samaritan Hospital, Cincinnati, Ohio.
Cincinnati, Ohio, United States