section_path: Diagnosis/Ultrasound
section_name: Ultrasound
paragraph_text: Ultrasound
  
  Obstetric ultrasonography can detect fetal abnormalities, detect multiple pregnancies, and improve gestational dating at 24 weeks. The resultant estimated gestational age and due date of the fetus are slightly more accurate than methods based on last menstrual period. Ultrasound is used to measure the nuchal fold in order to screen for Down syndrome.