Umbilical cord from and contains remnants of the yolk sac and allantois. It forms by the fifth week of development, replacing the yolk sac as the source of nutrients for the embryo. The cord is not directly connected to the mother's circulatory system, but instead joins the placenta, which transfers materials to and from the maternal blood without allowing direct mixing. The length of the umbilical cord is approximately equal to the crown-rump length of the fetus throughout pregnancy. The umbilical cord in a full term neonate is usually about 50 centimeters (20 in) long and about 2 centimeters (0.75 in) in
Retroverted uterus Retroverted uterus A retroverted uterus (tilted uterus, tipped uterus) is a uterus that is tilted posteriorly. This is in contrast to the slightly "anteverted" uterus that most women have, which is tipped forward toward the bladder, with the anterior end slightly concave. Between 1 in 3 and 1 in 5 women (depending on the source) have a retroverted uterus, which is tipped backwards towards the spine. The following table distinguishes among some of the terms used for the position of the uterus: A retroverted uterus should be distinguished from the following: Additional terms include: In most cases, a retroverted uterus