Birth stage three, which begins after the birth of the baby, further contractions expel the placenta, amniotic sac, and the remaining portion of the umbilical cord usually within a few minutes. Enormous changes take place in the newborn's circulation to enable breathing in air. In the uterus, the unborn baby is dependent on circulation of blood through the placenta for sustenance including gaseous exchange and the unborn baby's blood bypasses the lungs by flowing through the foramen ovale, which is a hole in the septum dividing the right atrium and left atrium. After birth the umbilical cord is clamped and cut,
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