Imaging Findings
Findings reveal single umbilical artery (two-vessel cord), umbilical cyst,
and clenched fist. These findings are associated with Trisomy 18. Amniocentesis
was performed.
Final
Diagnosis
Trisomy 18
Discussion:
The umbilical cord normally
contains 2 arteries and a single vein. Occasionally, cords have an absence
of one umbilical artery, with the left artery absent more commonly than
the right. Single umbilical arteries are associated more commonly with
fetal anomalies than normal cords.
Single umbilical arteries
are found twice as often in white women than in African American and Japanese
women. Diabetes increases the risk significantly. Two-vessel cords are
found more frequently in fetuses aborted spontaneously. The male-to-female
ratio is 0.85:1.
Single umbilical artery is
believed to be caused by atrophy of a previously normal artery, presence
of the original artery of the body stalk, or agenesis of one of the umbilical
arteries.
Of infants with a single umbilical
artery, 20-50% have associated fetal anomalies, including cleft lip, cardiovascular
abnormalities (especially ventricular septal defects and conotruncal defects),
ventral wall defects, central nervous system defects, esophageal atresia,
spina bifida, diaphragmatic hernia, cystic hygroma, hydronephrosis, dysplastic
kidneys, polydactyly, syndactyly, and marginal and velamentous insertion
of the cord.
Thirty percent have congenital
anomalies, which may include trisomy 13, trisomy 18, and triploidy; trisomy
21 is uncommon
Dr.
Sanjeev Mani, MD
Bandra Holy Family Hospital, Mumbai
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