gynecology and obstetrics
Placenta Previa
Key Points
Placenta previa is implantation of the placenta over or near the internal os of the cervix. Placenta previa typically manifests as painless vaginal bleeding after 20 weeks gestation, and placental abruption is usually associated with uterine pain and tenderness; however, clinical differentiation is often not possible. Consider placenta previa in all women who have vaginal bleeding after 20 weeks. For most first bleeding episodes before 36 weeks, recommend hospitalization, modified activity, and abstinence from sexual activity. Consider corticosteroids to accelerate fetal lung maturity if delivery may be required before 34 weeks or if bleeding occurs between 34 and 36 weeks in patients who have not been given corticosteroids before 34 weeks. Cesarean; delivery is indicated when the mother or fetus is unstable or, if mother and fetus are stable, at 36 weeks/0 days to 37 weeks/6 days. 