Judith Maloni, professor at the Frances Payne Bolton School of Nursing at Case Western Reserve University, said a comprehensive review of more than 70 evidence-based research articles challenges whether bed rest is healthy for mothers - or their babies.
Gaps in research also exist if bed rest harms or benefits the baby, Maloni said.
Bed rest for pregnant women experiencing early contractions or other pregnancy problems, such as high blood pressure, multiple babies, potential blood clotting or bleeding, can be prescribed for a few days or a few months.
"Over time, remaining in a resting position can lead to bone loss and muscle atrophy," Maloni said.
But for expectant mothers confided to bed for nearly 24 hours a day, it can also bring on depression, and possibly post traumatic shock disorder as women are left with nothing to do but worry that every contraction could bring about a pre-term birth.
The author makes her report in the special women's health issue of Biological Research for Nursing.