Increasing evidence shows that the long periods of bed rest can be harmful to the health of a pregnant woman, the New York Times reports.
Studies by NASA scientists, who used bed rest to simulate weightlessness in space, found that complete immobility during a long period of time can cause degeneration of person's musculoskeletal and cardiovascular systems.
According to the Times, degeneration can begin within 48 hours of bed rest, but it usually is "after birth that many bedridden mothers realize the extent of their deconditioning."
According to data, about 700,000 pregnant women annually in the U.S. are advised to go on bed rest, including nearly all women pregnant with more than one fetus.
Women often are told to go on bed rest if they are having blood spotting, contractions before 37 weeks' gestation, high blood pressure or a history of preterm labor, as well as if the fetus appears to be growing abnormally.
A majority of the women rest at home, while others are hospitalized.
The American College of Obstetricians and Gynecologists no longer advises bed rest to prevent preterm births because no large-scale, double-blind studies have proven the method effective, the Times reports.
According to the Times, four high-risk pregnancy specialists interviewed recommend that women on bed rest see a physical therapist and begin a light exercise program, if appropriate (Reynolds, New York Times, 3/22).