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
Use of restraints on pregnant women escape attempt." A number of health concerns have been raised by the American College of Obstetricians and Gynecologists (ACOG), the American Public Health Association, the American Medical Association and others surrounding the use of shackles on pregnant women. These concerns involve various increased health risks to the woman and her child, which arise at different points of shackling. While pregnant during incarceration, shackles can increase the risk of falling where a woman's center of gravity is shifted by the pregnant uterus. For example, restraints placed on a woman's wrists also prevent her from breaking a fall and protecting herself and