Bedrest has been frequently prescribed for various high-risk conditions during pregnancy. A common indication cited is concern regarding increased risk of spontaneous preterm birth, known to be associated with gestations with twins or higher-order multiples, polyhydramnios, presence of preterm contractions with or without evidence of cervical change, sonographic cervical shortening, presence of a dilated cervix with bulging membranes, or preterm premature rupture of membranes. In some cases, there is concern that excessive movement may increase the risk of antepartum hemorrhage, as may be with placenta previa, with or without a higher risk of a morbidly adherent placenta or a vasa previa. It is also thought that improved splanchnic perfusion with bedrest may enhance blood supply to the uterus with possible benefit in conditions such as preeclampsia (or gestational hypertension) or fetal growth restriction. However, there is no evidence of any benefit of bedrest or reduced activity during pregnancy for either of these conditions. On the contrary, there is evidence of harm, in addition to the fact that exercise is known to be beneficial in pregnancy.