Morphological and histological study of umbilical cord atdelivery

The umbilical cord is a narrow tube-like structure that connect the developing baby to the placenta. The umbilical cord begins to form at five weeks after conception .It becomes progressively longer until 28 weeks of pregnancy, reaching an average length of 55-65 cm long with outer amniotic epithelium, bulk is composed of mucoid Wharton’s jelly, The cord contains three blood vessels: two arteries and one vein .The cord diameter was 1cm or more (1). The deoxygenated fetal blood leaves the fetus in two umbilical arteries that pass through the umbilical cord .When they reach the fetal surface of the placenta, these vessels divided into many branches which enter the chorionic villi. The oxygenated blood returns to the fetus via the venules and veins in the choronic villi. These join to form the umbilical vein in the umbilical cord (2). The insertion of the umbilical cord to the placenta was central insertion into placenta at midgestation; insertion may become more eccentric as gestation proceeds (3). Microscopically the umbilical arteries composed of double layered muscular wall, no internal elastic lamina. The umbilical vein larger in diameter, thin wall with single layer of disorganized circular smooth muscle and an internal elastic laminal. A number of abnormalities can affect the umbilical cord. The cord may be too long or too short .It may connect improperly to placenta or become knotted or compressed (4,5) .Cord abnormalities can lead to problems during prolapsed or labor and delivery like: single umbilical artery ,umbilical cord prolapsed vasaprevia, punchal cord umbilical cord knots and umbilical cyst(6). The aim of the present work was to recognize the site of umbilical cord insertion and to study the histological appearance of the cord at different gestational periods to develop a better understanding of the causes of birth defects