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1: Am J Obstet Gynecol. 2005 Nov;193(5):1709-15.Click here to read Links

Embryogenesis of fused umbilical arteries in human embryos.

Yamada S, Hamanishi J, Tanada S, Tachibana M, Mimura R, Fujii S, Shiota K.

Congenital Anomaly Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan. shyamada@cac.med.kyoto-u.ac.jp

OBJECTIVE: The objective of this study was to elucidate the embryologic basis of fused umbilical arteries in the human. STUDY DESIGN: Twenty-nine human embryo specimens at Carnegie stages 11 through 15 (4-5 weeks after fertilization) were examined histologically, with special reference to the development of umbilical arteries. RESULTS: All embryos at Carnegie stage 11 and 12 had fused umbilical arteries, and 66% of Carnegie stage 13 embryos and 29% of Carnegie stage 14 embryos still had the condition. None of the embryos at Carnegie stage 15 or older had fused umbilical arteries, but there were always 2 arteries present in their umbilical cords. CONCLUSION: Our data suggest that (1) a single umbilical artery splits into 2 as the developmental stage of the embryo advances, (2) that fused umbilical arteries represent a remnant of the embryonic phenotype, and (3) that fused umbilical arteries are embryologically distinct from true single umbilical artery.

PMID: 16260215 [PubMed - indexed for MEDLINE]