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Updated: Mar 15, 2026

Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye
Published on: September 5, 2011
Umbilical Cord Occlusion via Laser Coagulation in Monochorionic Multifetal Gestations before and after 20 Weeks of
Jennifer R King1, Charlotte L Conturie, Joseph G Ouzounian
1Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Keck School of Medicine, University of Southern California, Los Angeles, Calif., USA.
Introduction:
Umbilical cord occlusion (UCO) utilizing laser photocoagulation is often not considered an option for selective termination after 20 weeks of gestation due to reported limitations of the procedure because of umbilical cord size. We compared outcomes after laser umbilical cord occlusion (L-UCO) before and after 20 weeks of gestation.
Materials And Methods:
We examined all patients with monochorionic- diamniotic twins and higher-order multiples (monoamniotic excluded) that underwent L-UCO at our facility between 2006 and 2014. Statistical analysis was performed using Fisher's exact and Kruskal-Wallis tests as appropriate.
Results:
Of 43 L-UCO cases, 11 cases (25.6%) had a discordant anomaly, and 32 cases (74.4%) had twin reversed arterial perfusion (TRAP) sequence. We achieved complete vascular occlusion in 100% (43/43) of cases of attempted L-UCO. There were 22 cases (51.2%) with gestational age ≤20 weeks, and 21 cases (48.8%) with gestational age >20 weeks. Perioperative patient characteristics and outcomes did not differ between the two groups. Survival rates were 90.9% (20/22) and 100% (21/21) at ≤20 weeks of gestation and >20 weeks of gestation, respectively.
Discussion:
The results of this study suggest that L-UCO is a reasonable surgical modality for patients prior to and beyond 20 weeks of gestation.
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