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Updated: May 31, 2026
09:04
Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas
Published on: September 5, 2011
Single umbilical artery in twin pregnancies
1Department of Obstetrics and Gynecology, Neue Frauenklinik Luzern, Luzern, Switzerland.
Summary
The incidence of single umbilical artery (SUA) is higher in twin pregnancies than in singletons, with no difference between monochorionic (MC) and dichorionic (DC) twins. This finding suggests SUA may not be solely genetic and impacts fetal growth.
Area of Science:
- Perinatology
- Fetal Medicine
- Obstetrics
Background:
- Single umbilical artery (SUA) is a common umbilical cord anomaly.
- The incidence and implications of SUA in twin pregnancies require further investigation.
Purpose of the Study:
- To determine the antenatal incidence of SUA in twin pregnancies stratified by chorionicity.
- To evaluate the association between SUA and pregnancy outcomes in twins.
Main Methods:
- Ultrasound evaluation of 174 consecutive twin pregnancies.
- Targeted sonographic assessment of umbilical cord and vessels.
- Determination of chorionicity using standard ultrasound criteria.
Main Results:
- SUA identified in 9.8% of twin pregnancies (5.2% of fetuses).
- No significant difference in SUA incidence between dichorionic (DC) and monochorionic (MC) twins.
- Higher prevalence of fetal growth restriction and discordant birth weight in SUA cases, though not statistically significant.
Conclusions:
- SUA incidence in twins exceeds that in singletons, irrespective of chorionicity.
- Discordance for SUA in identical twins challenges a purely genetic etiology.
- Impaired compensatory dilatation of SUA in twins may contribute to fetal growth restriction.
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