The lower edge of the placenta is close to the cervical opening, which may cause miscarriage or preterm labor, so bed rest is required.
Under normal circumstances, the placenta is attached to the posterior, anterior or lateral wall of the uterus. If the fetus is not stable in early pregnancy and needs to obtain nutrition from the placenta, the lower edge of the placenta is close to the cervical os, which may result in poor blood supply locally, leading to the fetus not being able to obtain nutrients and causing miscarriage, so it is necessary to lie down in bed to support the fetus.
If the lower edge of the placenta is close to the cervical opening after 28 weeks of pregnancy, the placenta becomes anterior, the stretch of the uterus increases in late pregnancy, while the placenta lacks stretch, if the pregnant woman is strenuous exercise may cause the lower part of the uterus or the cervical opening and the placenta to hemorrhage, which can easily lead to preterm labor.
Therefore, pregnant women whose lower edge of the placenta is close to the cervical opening should take bed rest according to medical advice.