Posterior Placenta Grade 2: Partial Cervical Coverage and Previa Risk

Placental grading (Grannum) by ultrasound echogenicity: Grade 0 (early) → Grade 3 (mature). Grade 2 = moderate maturity (typically 36–38 wks), with indentations reaching basal plate but not full thickness.

Posterior Grade 2

• Placenta on posterior uterine wall (normal location).
• Grade 2 maturity = appropriate for late third trimester.
• Partially covering internal os = low-lying placenta (edge <2 cm from os).

Clinical Significance

• If fully covering os → placenta previa (total/partial) → mandatory C-section, risk of hemorrhage.
• If low-lying but not covering → may resolve as lower segment forms; monitor with serial US.
• Posterior location not inherently risky; anterior placenta can obscure fetal heart tones.

Management

Repeat US at 32–34 wks. If persistent previa → planned C-section 36–37 wks. Avoid digital cervical exam. Counsel on bleeding precautions.