Obstetric Ultrasound Normal Pregnancy Vs Placenta Previa | Low-Lying, Marginal, Partial, Complete
*Cases
Low-Lying Placenta - 0:00
Marginal Placenta Previa - 7:06
Partial Placenta Previa - 9:29
Complete Placenta Previa - 10:40
Placenta Previa
Abnormally low position of the placenta. Placenta lies closer to the cervix or covers it.
Causes:
- Previous Cesarean Delivery
- Multiple Pregnancies
- Previous Placenta Previa
- Maternal Age: Women over 35 years old are at higher risk.
- Smoking
- Uterine Surgery such as fibroid removal
- In Vitro Fertilization (IVF)
Diagnosis:
- Second-Trimester Ultrasound (18-20 weeks): Placenta previa is more commonly identified during the mid-pregnancy ultrasound, usually around 18 to 20 weeks. However, some cases detected at this stage may resolve by the third trimester as the uterus grows and the placenta moves away from the cervix.
- Third-Trimester Ultrasound (28-32 weeks): If placenta previa is suspected or diagnosed earlier in the pregnancy, follow-up ultrasounds are typically conducted around 28 to 32 weeks to see if the condition has resolved. Persistent placenta previa at this stage is more likely to continue to term and require special management.
Low-Lying Placenta: Placental edge is less than 2 cm from the internal os
Marginal Placenta Previa: Placenta touches the margin of the cervix but does not reach the internal os
Partial Placenta Previa: Placenta partially covers the internal os
Complete: Placenta completely covers the internal cervical os.