Which factor is NOT a risk factor for abruptio placenta?

Walking is not considered a risk factor for abruptio placenta because it is a normal, everyday activity that does not exert significant physical stress on the body or the placenta. Abruptio placenta, or the premature separation of the placenta from the uterus, is typically associated with conditions that increase vascular stress or lead to trauma.

On the other hand, hypertension, cigarette smoking, and cocaine use are known risk factors. Hypertension increases the strain on blood vessels and can affect placental blood flow, potentially leading to premature separation. Cigarette smoking is linked to several adverse pregnancy outcomes, including placental issues, due to its effects on blood circulation and placental health. Cocaine use poses significant risks as well, since it can cause vasoconstriction, leading to decreased blood flow to the placenta and increasing the likelihood of separation.

Thus, walking does not share the same harmful characteristics associated with these other factors and is not linked to the risk of abruptio placenta.