Dating scan accuracy
Advanced Ultrasound – This exam is similar to the standard ultrasound, but the exam targets a suspected problem and uses more sophisticated equipment.
Doppler Ultrasound – This imaging procedure measures slight changes in the frequency of the ultrasound waves as they bounce off moving objects, such as blood cells.
Most often used during the early stages of pregnancy.
Standard Ultrasound – Traditional ultrasound exam which uses a transducer over the abdomen to generate 2-D images of the developing fetus.
Your healthcare provider uses a transducer to produce sound waves into the uterus.However, variations in each woman’s cycle and each pregnancy may hinder the accuracy of the gestational age calculation.If your healthcare provider uses an ultrasound to get an estimated delivery date to base the timing of your prenatal care, the original estimated gestational age will not be changed.Transvaginal scans may be used early in pregnancy to diagnose potential ectopic or molar pregnancies.There is not a recommended number of ultrasounds that should be performed during routine prenatal care.