How to report an NT (76813) performed without obtaining the biochemical markers
The nuchal translucency ultrasound scan and blood tests are often done together in what is called the combined first-trimester genetic screen. Part of the first trimester genetic screen uses ultrasound to measure the thickness of the area at the back of the baby's neck. Obtaining the biochemical markers is not part of the 76813 ultrasound CPT.
The required elements of the 76813 ultrasound code include:
Fetal crown-rump measurement
Observation of fetal cardiac activity
Observation of the embryo at high magnification until the embryonic neck is in a neutral position and spontaneous embryonic movement allows for differentiation between the outer edge of the nuchal skin and the amnion
At least three separate measurements of the largest distance between the inner borders of the fetal nuchal translucency
Comparison of the largest nuchal translucency measurement from an acceptable image to crown-rump length and gestational age specific medians
Written documentation of each component of the examination and permanent documentation of ultrasound images.
Therefore, reporting the 76813 is appropriate if all the elements mentioned above are documented. It may be helpful to document in the report if the patient opted not to proceed with the biochemical markers portion of the first trimester genetic screen test.