CurrentBlue Cross Blue Shield - Rhode IslandPolicy N/A

First-Trimester Detection of Down Syndrome Using Fetal Ultrasound Markers Combined with Maternal Serum Assessment

Policy governing coverage of first-trimester screening for Down syndrome that combines maternal serum markers with fetal ultrasound markers (nuchal translucency and fetal nasal bone assessment) for BlueCHiP for Medicare and Commercial products.

Policy Summary

PayerBlue Cross Blue Shield - Rhode Island

PolicyFirst-Trimester Detection of Down Syndrome Using Fetal Ultrasound Markers Combined with Maternal Serum Assessment

Policy CodePolicy N/A

Change TypeNo material change

Effective DateNov 17, 2005

Next Review DateN/A

Key ActionReport first-trimester fetal nuchal translucency measurement using CPT 76813 (single gestation) or 76814 (additional gestation) when performed.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

10-13 wksNT gestational window

11-14 wksNasal bone window

76813/76814Covered CPTs

0.09%-0.3%NT >=4.0 mm subgroup

69% / 81%

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Coverage determinations and medical necessity

Coverage determinations

Coverage decisions for BlueCHiP for Medicare and Commercial products:

Combined first-trimester screening: First-trimester screening incorporating maternal serum markers and measurement of fetal nuchal translucency may be considered medically necessary for women who are adequately counseled and desire information on the risk of having a child with Down syndrome.

Supported by multicenter trials (SURUSS, FASTER) and observational studies showing combined screening is at least as accurate as alternatives.

NT alone: First-trimester screening using nuchal translucency measurement alone is not covered for BlueCHiP for Medicare and is not medically necessary for Commercial products due to insufficient evidence of health outcome benefit.

Large studies (SURUSS, FASTER) found NT alone is inferior to combined screening; very small subgroup with NT >= 4.0 mm (0.09%-0.3% of cases) may have high likelihood of Down syndrome but does not change coverage stance.

Fetal nasal bone assessment: First-trimester screening incorporating fetal nasal bone assessment is not covered for BlueCHiP for Medicare and is not medically necessary for Commercial products because evidence is insufficient, test performance is variable, and results are operator-dependent.

Some studies suggest modest incremental benefit when combined with NT and serum markers, but the degree of benefit is unclear; inability to visualize nasal bone is an unsuccessful exam rather than a positive result.

For BlueCHiP for Medicare and Commercial products, first‑trimester screening that combines maternal serum markers with measurement of fetal nuchal translucency may be considered medically necessary for women who are adequately counseled and who desire information about the risk of having a child with Down syndrome. However, first‑trimester screening using nuchal translucency alone is not covered for BlueCHiP for Medicare and is not medically necessary for Commercial products due to insufficient evidence of benefit. Similarly, first‑trimester screening that incorporates fetal nasal bone assessment is not covered for BlueCHiP for Medicare and is not medically necessary for Commercial products because the evidence is insufficient to determine effects on health outcomes.

For Commercial products specifically, first‑trimester screening using nuchal translucency (NT) measurement alone is designated not medically necessary because multicenter studies (SURUSS, FASTER) showed NT alone is overall inferior to combined first‑ or second‑trimester screening. A very small subgroup with NT ≥ 4.0 mm has a high likelihood of Down syndrome (affecting approximately 0.09%–0.3% of cases), but this exception does not change the general noncoverage stance. Fetal nasal bone assessment is also designated not medically necessary for Commercial products because published accuracy is variable and operator‑dependent; limited evidence suggests only a possible modest incremental benefit when combined with NT and serum markers, but the degree of benefit is unclear.

Billing codes and coding guidance

Covered CPT Codes for NT measurementCPTCovered

76813	Ultrasound, pregnant uterus, real time with image documentation, first trimester fetal nuchal translucency measurement, transabdominal or transvaginal approach; single or first gestation
76814	Ultrasound, pregnant uterus, real time with image documentation, first trimester fetal nuchal translucency measurement, transabdominal or transvaginal approach; each additional gestation (List separately in addition to code for primary procedure)

Unlisted code for nasal bone assessmentCPT

unlisted

No specific CPT code for ultrasound assessment of fetal bone translucency; report with an unlisted code.

NT high threshold examples — NT >= 4.0 mm subgroup note

High‑NT subgroup thresholdNT >= 4.0 mm (very small subgroup where additional testing may be unnecessary)

Estimated frequencyAffects approximately 0.09%–0.3% of cases

Clinical implicationVery high likelihood of Down syndrome in this subgroup; additional testing may not be necessary in some cases

Provider requirements, billing, and operational notes

Prior Authorization

Prior authorization

Not applicable

Note

Recommended repeat exam

If the fetal nasal bone is absent on ultrasound performed at 11–12 weeks' gestation, a repeat ultrasound about 2 weeks later is sometimes recommended to confirm absence before concluding a positive result.

Repeat exam recommended when nasal bone absent at 11–12 weeks: re-scan ~2 weeks later

Billing Rule

Billing and reporting

Clinical background and diagnostic context

A definitive diagnosis of Down syndrome requires invasive diagnostic testing such as amniocentesis or chorionic villus sampling (CVS), procedures that carry a risk of miscarriage. First‑trimester biochemical screening (free beta‑hCG and PAPP‑A) combined with NT measurement can detect many cases earlier and may approach the accuracy of alternative tests, but screening results are not diagnostic; positive screening findings typically require counseling and consideration of diagnostic testing to confirm the diagnosis.

Key definitions

Nuchal translucency — definition and measurement window/details

DefinitionNuchal translucency (NT): ultrasound measurement of subcutaneous edema at the fetal neck measured as the maximal thickness of the sonolucent zone between the inner aspect of the fetal skin and the outer aspect of the soft tissue overlying the cervical spine or occipital bone.

Gestational age windowPerformed at 10–13 weeks of gestation

Measurement techniqueMeasured as the maximal thickness of the sonolucent zone between fetal skin and overlying soft tissue on ultrasound

Clinical correlationIncreased NT in the first trimester is associated with chromosomal defects, most commonly Down syndrome (trisomy 21) and also trisomy 18 and 13.

Fetal nasal bone assessment — definition and view details

Definition