BY4CZZZ
Ultrasonography Second Trimester, Single Fetus to None with None, None Approach
Procedural Specifications
| Clinical Axis | Detail Definition |
|---|---|
| Section | B Imaging |
| Body System | Y Fetus and Obstetrical |
| Operation | 4 Ultrasonography |
| Body Part | C Second Trimester, Single Fetus |
| Approach | Z None |
| Device | Z None |
| Qualifier | Z None |
Operation Definition
Real time display of images of anatomy or flow information developed from the capture of reflected and attenuated high frequency sound waves
Procedure Overview
Ultrasonography of the fetus and obstetrical body system is the imaging family behind the routine and follow-up scans performed throughout pregnancy, using sound waves reflected off tissue to produce a real-time picture of the fetus, placenta, amniotic fluid, and related structures. It is the primary way clinicians confirm a pregnancy is progressing normally, estimate gestational age, check fetal growth and position, and screen for structural abnormalities.
Because it is safe, widely available, and gives an immediate live view, ultrasound is used repeatedly across a single pregnancy rather than just once, from early dating scans through anatomy surveys and later growth checks. It is also the modality most often used first when a concern arises, such as bleeding, reduced fetal movement, or an unclear due date, with other imaging like MRI reserved for cases needing more detail.
Anatomy & Axis Detail
Second Trimester, Single Fetus
The second trimester single-fetus ultrasound is the setting for the detailed fetal anatomic survey, evaluating the brain, spine, heart, abdominal organs, limbs, and face for structural abnormalities, alongside placental location and amniotic fluid volume. Fetal biometry obtained here, including biparietal diameter, head circumference, abdominal circumference, and femur length, is used both to confirm dating established earlier and to begin tracking growth trends. This is typically the most comprehensive scan of an uncomplicated pregnancy and often the point at which fetal sex is identified if requested. Findings that are equivocal, such as a soft marker or an incompletely visualized structure, commonly prompt a follow-up scan later in gestation, and documentation should reflect which anatomic components were adequately versus inadequately visualized.
Coding & Documentation
Coders assign from this family when documentation confirms the exam targeted the fetus or obstetrical structures rather than the mother's own pelvic anatomy, and should note the specific purpose, such as a dating scan, anatomy survey, or growth assessment, since that detail can matter for the encounter as a whole even though it does not change the root operation. A common error is not distinguishing a fetal ultrasound from an ultrasound of the maternal reproductive organs performed during the same visit, or overlooking that a multiple gestation pregnancy involves more than one fetus, which the documentation should address individually.
Commonly Confused With
The closest related family is MRI of the fetus and obstetrical system, separated purely by the modality used rather than the reason for the exam. It is also commonly confused with ultrasonography of the female reproductive system, where the deciding factor is whether the images and interpretation are describing the fetus and pregnancy structures or the mother's uterus and ovaries as the subject of the study.