Sonography Assessment of Gestational Age

Excerpt

Sonography can be used at different levels of gestational development to determine the age of the growing fetus. Determining the correct age impacts later care of the woman and fetus, and may affect dates that determine the viability of the fetus, expected delivery date, and appropriate growth rate. The most accurate method to determine gestational age is during weeks 8 through 12 when the crown-rump length can be determined, and the fetus is in its greatest and most consistent rate of growth.

Earlier and later developmental time periods may also remain useful in the appropriate clinical context to confirm dates. Conveniently, portable ultrasound machines employed at the point of care may be as accurate as higher-end machines in determining gestational age.