Final answer:
A nurse should inform the client that while reaching over the head is a restrictive belief related to the umbilical cord wrapping around an infant's neck, it is not medically supported. The umbilical cord's position is not influenced by the mother's arm movements, and this cord is safely managed immediately after birth.
Step-by-step explanation:
Among various cultural beliefs surrounding pregnancy, some ethnic groups advise that expectant mothers should not reach over their heads to prevent the umbilical cord from wrapping around the infant's neck. This is an example of a restrictive belief, which reflects cultural guidelines on what should be avoided to ensure a positive pregnancy outcome. However, movements of the mother's arms do not have any physiological impact on the umbilical cord's positioning around the infant. A nurse should reassure the client that while such beliefs are culturally significant, they are not supported by medical evidence. The reality is that the umbilical cord is cut and clamped immediately after birth, and the cord itself shrivels and forms the navel within a few weeks post-delivery. It is important to respect cultural practices but also provide clients with factual information to prevent undue stress or worry during pregnancy.