This paper deals with evaluation of the prevalence rate, course and number of placental cotyledons supplied by branches ramifying from Hyrtl’s anastomotic vessels. The study was carried out using the corrosion method on 106 human placentas from normal fullterm single and twin pregnancies. Such branches were found in 11.5% of cases. The number of cotyledonous arteries arising from the branches varied from 0 to 6, whereas the lumen diameter in the vessels ranged from 0.2 to 2.8 mm.

Keywords: Umbilical Arteries, Hyrtl’s anastomoses, Anatomy, human placenta