Why is an ultrasound exam so important in pregnancy?

During the first trimester, a fetal ultrasound accurately assigns the gestational age of a pregnancy.  It is also the time when the health of an early pregnancy can be evaluated with the measurement of the nuchal translucency – a precise measurement of a “translucent” area on the back of the developing fetal neck (performed between 11-14 weeks).  This measurement, when performed in combination with a first trimester and second trimester blood test, provide a risk assessment for the most common chromosome abnormalities

During the second trimester, a detailed anatomic survey rules out most birth defects when done by a specialized perinatal center.  During that exam, stringent parameters are followed, established by the American Institute in Ultrasound Medicine (AIUM) regarding anatomic structures that must be evaluated – assuring to the limitation of ultrasound itself, you baby is thoroughly examined.

During the third trimester, a fetal ultrasound evaluates the size of the developing baby and identifies pregnancies with abnormal growth.  In the event of a growth abnormality, advanced imaging techniques including evaluation of blood flow velocities and wave forms through specific blood vessels in the brain,  heart, liver and umbilical cord can be undertaken.  In addition, biophysical parameters such as fetal breathing, tone and movement can also be used to determine the health of the developing baby in combination with a fetal non stress test.