Placenta praevia

Placenta praevia
Other names	Placenta previa
Diagram showing a placenta previa (Grade IV)
Specialty	Obstetrics
Symptoms	Bright red vaginal bleeding without pain[1]
Complications	Mother: Bleeding after delivery[2] Baby: Fetal growth restriction[1]
Usual onset	Second half of pregnancy[1]
Risk factors	Older age, smoking, prior cesarean section, labor induction, or termination of pregnancy[3][4]
Diagnostic method	Ultrasound[1]
Differential diagnosis	Placental abruption[1]
Treatment	Bed rest, cesarean section[1]
Frequency	0.5% of pregnancies[5]

Placenta praevia is when the placenta attaches inside the uterus but in a position near or over the cervical opening.^[1] Symptoms include vaginal bleeding in the second half of pregnancy.^[1] The bleeding is bright red and tends not to be associated with pain.^[1] Complications may include placenta accreta, dangerously low blood pressure, or bleeding after delivery.^[2][4] Complications for the baby may include fetal growth restriction.^[1]

Risk factors include pregnancy at an older age and smoking as well as prior cesarean section, labor induction, or termination of pregnancy.^[6][3][4] Diagnosis is by ultrasound.^[1] It is classified as a complication of pregnancy.^[1]

For those who are less than 36 weeks pregnant with only a small amount of bleeding recommendations may include bed rest and avoiding sexual intercourse.^[1] For those after 36 weeks of pregnancy or with a significant amount of bleeding, cesarean section is generally recommended.^[1] In those less than 36 weeks pregnant, corticosteroids may be given to speed development of the baby's lungs.^[1] Cases that occur in early pregnancy may resolve on their own.^[1]

Placenta praevia affects approximately 0.5% of pregnancies.^[5] After four cesarean sections, however, it affects 10% of pregnancies.^[4] Rates of disease have increased over the late 20th century and early 21st century.^[3] The condition was first described in 1685 by Paul Portal.^[7]