What complications are associated with bed rest?

Deep Vein Thrombosis: Pregnant women are more prone to forming blood clots in the deep veins of the leg and pelvis, especially with immobility associated with bedrest.

Muscular atrophy: Some women placed on strict bedrest, especially those with a cerclage in place, may be told to avoid any straining with their abdominal muscles. Depending on how long they remain on bedrest, they may develop moderate to severe atrophy of the abdominal core muscle group as well as the legs, buttocks and arms.