title: Ultrasonic placental grading in high risk pregnancy.
mesh_terms: D005260:Female; D005325:Fetal Organ Maturity; D006801:Humans; D008168:Lung / Q000196:embryology*; D010920:Placenta / Q000032:analysis*; D011247:Pregnancy; D011248:Pregnancy Complications; D014463:Ultrasonography