CurrentColorado Rocky Mountain Health PlansPolicy N/A

Chromosomal microarray (CMA) testing (prenatal, stillbirth, pediatric indications)

This policy section describes clinical indications, diagnostic yield evidence, and references from professional societies for use of chromosomal microarray (CMA) including prenatal (amniocentesis/CVS), evaluation of pregnancy loss/stillbirth, fetal structural anomalies (including fetal growth restriction and congenital heart defects), and pediatric neurodevelopmental indications. It summarizes test utility, incremental yield over karyotype, limitations, and guidance from ACMG, ACOG, SMFM, SOGC/CCMG.

Policy Summary

PayerColorado Rocky Mountain Health Plans

PolicyChromosomal microarray (CMA) testing (prenatal, stillbirth, pediatric indications)

Policy CodePolicy N/A

Change TypeTerminology, definitions, and reference link updates

Effective Date

Next Review Date

Key ActionDocument the clinical indication on the requisition and in the medical record to support CMA ordering and potential coverage.

SourceLink

POLICY UPDATE CHANGES

Added reference link to the Medical Policy titled 'Genetic Testing for Cardiac Disease' and removed two other policy links.

Updated Coverage Rationale terminology: replaced 'Multiple anomalies' with 'Multiple Congenital Anomalies' and 'Developmental Delay' with 'Global Developmental Delay'.

Added definitions for Autism Spectrum Disorder and Congenital Anomaly; removed definition of 'Prenatal Diagnosis'; updated definitions for Global Developmental Delay, Intellectual Disability, and Well-Delineated Genetic Syndrome.

Updated supporting information sections: Description of Services, Clinical Evidence, and References to reflect current information.

3%-10%

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Coverage Summary

This policy section addresses clinical use of chromosomal microarray (CMA) — including aCGH and SNP arrays — for prenatal testing (amniocentesis/CVS), evaluation of pregnancy loss and stillbirth, and postnatal assessment of neurodevelopmental disorders and congenital anomalies. Coverage stance is mixed: CMA is supported and considered medically necessary for several defined prenatal and pediatric indications (e.g., fetal structural anomalies, stillbirth, products of conception when further cytogenetic analysis is intended, and first-tier evaluation of GDD/ID/ASD), while use outside those established contexts is considered unproven or not medically necessary pending sufficient evidence.

Medical Necessity — Indications and When CMA Is Recommended

Clinical Indications / When CMA is Recommended or Considered

Covered/recommended when the following clinical scenarios apply:

ANY of the following

Prenatal indications: invasive prenatal testing (eg, amniocentesis, chorionic villus sampling, fetal tissue sampling) for detection of chromosomal abnormalities
Used to evaluate embryo/fetus when invasive testing is performed
Intrauterine fetal demise or stillbirth
Evaluation of fetal tissue following loss
Testing the products of conception following pregnancy loss
To identify chromosomal causes of pregnancy loss
Confirmatory testing for abnormal or equivocal chromosome microarray findings in a fetus or neonate (to clarify or confirm results)
Includes use for reflex/confirmatory analysis when initial CMA yields uncertain results
Neonatal and pediatric indications: individuals with developmental delay, global developmental delay, intellectual disability, autism spectrum disorder, multiple congenital anomalies not specific to a well-delineated genetic syndrome, or isolated severe congenital heart disease
For diagnosis/evaluation when a specific syndrome is not suspected and CMA can identify CNVs contributing to the phenotype
Evaluation of a biological parent or sibling of a fetus or child with an abnormal or equivocal finding on chromosome microarray testing results
Family-member testing to aid interpretation or recurrence risk assessment

When CMA may be considered optional or as alternative to karyotype

Optional or alternative considerations where CMA may be used instead of karyotype or considered on a case-by-case basis:

ANY of the following

When conventional karyotype may detect abnormalities but CMA is preferred for higher resolution detection of submicroscopic copy number variants
CMA provides greater sensitivity for submicroscopic CNVs compared with karyotype
Situations where clinical presentation is less specific and higher-resolution genome-wide analysis is desired as an alternative to karyotype
Consider CMA when phenotype is nonspecific and broader interrogation may yield diagnostic findings
Cases where clinician and patient preference favor CMA over karyotype after counseling about the differences in detection scope, turnaround time, and potential for variants of uncertain significance
Shared decision-making after pre-test genetic counseling supports optional use of CMA

Not Covered / Experimental Considerations

A mixed coverage stance reflects that CMA has clear, guideline-supported roles in many scenarios but that newer genome-wide tests may offer higher diagnostic yield in select populations. Systematic reviews show WGS can yield substantial incremental diagnoses over CMA (e.g., ~26% overall incremental yield versus CMA in congenital anomaly cohorts), yet authors conclude evidence is currently insufficient to support routine replacement of CMA by WGS. Parallel meta-analyses demonstrate that CMA provides measurable incremental yield over karyotype in fetal indications (notably when structural anomalies are present), so CMA remains a recommended first-line or complementary test in many prenatal and pediatric situations per professional guidance.

Inferred limits from the brief: CMA is most valuable when applied to the documented, guideline-consistent indications (fetal structural anomalies, stillbirth, pregnancy loss when further cytogenetic analysis is desired, and postnatal evaluation of GDD/ID/ASD and certain CHD presentations). Where evidence suggests substantially higher yields from WES/WGS (for example, in some multisystem structural anomaly cohorts or when monogenic disorders are suspected), WGS/WES may be considered but are not endorsed as routine replacements for CMA; clinical judgment, phenotype, and guideline recommendations should guide whether broader sequencing is pursued or CMA is performed first or concurrently.

Coding

Applicable ICD-10 diagnoses listed in this policy excerptICD-10

Q93.51	Angelman syndrome
Q93.52	Phelan-McDermid syndrome
Q93.59	Other deletions of part of a chromosome
Q93.81	Velo-cardio-facial syndrome
Q93.82	Williams syndrome
Q93.88	Other microdeletions
Q93.89	Other deletions from the autosomes
Q93.9	Deletion from autosomes, unspecified
Q95.2	Balanced autosomal rearrangement in abnormal individual
Q95.3	Balanced sex/autosomal rearrangement in abnormal individual

1–10 of 32

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Provider Actions / Prior Authorization & Documentation

Documentation Required

Indication documentation for CMA

Indication documentation: Document the clinical indication(s) supporting chromosome microarray analysis (CMA), including presenting phenotype, relevant findings on physical exam, developmental concerns, family history, and, for prenatal cases, indication for invasive testing or pregnancy loss. Include test type selected (targeted vs genome‑wide) and rationale tied to the phenotype. Do not include billing or code lists in this documentation note.

Documentation Required

Genetic counseling and informed consent

Genetic counseling requirement: Ensure pretest and posttest genetic counseling are provided and documented. Counseling should cover test purpose, possible results (pathogenic, likely pathogenic, VUS, benign), limitations, implications for the pregnancy or individual and family, and potential incidental findings. For prenatal CMA, document that informed consent addressing the scope of testing and potential fetal/parental implications was obtained prior to testing.

Background & Evidence

Chromosomal microarray (CMA), including array comparative genomic hybridization (aCGH) and single nucleotide polymorphism (SNP) arrays, is a high-resolution genome-wide assay that detects copy-number variants (CNVs), uniparental disomy, aneuploidies, and other chromosomal alterations with greater sensitivity than conventional karyotype.

CMA is used in prenatal diagnosis (amniocentesis, chorionic villus sampling), evaluation of products of conception and stillbirth, and in postnatal assessment of neurodevelopmental disorders and congenital anomalies (for example, Autism Spectrum Disorder, Global Developmental Delay/Intellectual Disability, and congenital heart defects). Evidence demonstrates measurable incremental diagnostic yield over karyotype in many fetal indications — particularly when structural anomalies are present — and meaningful detection rates in pediatric indications such as GDD/ID and ASD.

Limitations include variable study designs and inclusion criteria across published cohorts and meta-analyses, heterogeneity of CMA platforms and workflows, challenges interpreting variants of uncertain significance (VUS), occasional need for parental testing to clarify inheritance, and that CMA does not detect single-nucleotide variants or many sequence-level pathogenic variants detectable by WES/WGS; in some settings (e.g., multisystem anomalies), sequencing tests may show higher incremental yield.

Study / Guideline	Key finding
Sapantzoglou et al. (2026)
Incremental CMA yield in fetal growth restriction: isolated FGR 3% (95% CI 2-5%), FGR + US 4% (95% CI 3-5%), FGR + SM 10% (95% CI 7-13%)
Matarrelli et al. (2025)
Increased nuchal translucency: composite adverse outcome 42%; CNVs detected in 4.3% of fetuses tested
Zheng et al. (2025)
SNP-based CMA in amniotic fluid (n=5,116): aneuploidies common; pCNV frequency similar across groups (2.11%-3.68%); recommended strongly for CHD + SM
Lu et al. (2024)
CMA diagnostic yield 15.3% vs karyotype 8.3% in fetuses with confirmed CHD (n=642); higher yield with extracardiac anomalies
Shreeve et al. (2024)
WGS showed significant incremental yield over CMA (26% overall) but evidence insufficient to support routine WGS over CMA/WES
Systematic review (epilepsy genetic testing)
Overall diagnostic yield 17% across tests; CMA yield 9% (genome 48%, exome 24%, panels 19%)
Miclea et al. (2022)
Pathogenic CNVs/uniparental disomy in 35/189 (18.5%) of children with GDD/ID
Harris et al. (2020)
In 299 toddlers with ASD who received CMA, 9.0% had pathogenic variants; 63% of those received further medical recommendations
AAP 2025 (Rodan et al.)
Recommend CMA as first-tier agnostic evaluation for GDD/ID, along with WES (sequential or concurrent); if WGS performed initially, CMA may be deferred
ACMG (2010/2023)
Recommend CMA as first-line postnatal test for multiple congenital anomalies, apparently nonsyndromic developmental delay/ID, and ASD; phenotype-driven test selection
CCMG (2023)
Recommend CMA as first-tier for GDD, ID, or ASD

Definitions

CMA -> Chromosomal microarray, including aCGH and SNP array, a genome-wide assay to detect copy-number variants (CNVs), uniparental disomy, aneuploidies, and other structural chromosomal alterations.

pCNV -> Pathogenic copy number variant; a CNV classified as pathogenic or likely pathogenic and considered causative or contributory to the clinical phenotype.

VUS -> Variant of uncertain significance; a genomic change identified on CMA whose clinical impact is not currently classifiable as benign or pathogenic and which may require parental testing or further evaluation.

FGR -> Fetal growth restriction; restricted fetal growth identified on ultrasound that may be associated with structural anomalies or other markers and in which CMA has variable incremental yield depending on accompanying findings.

CHD -> Congenital heart defects; structural cardiac anomalies detectable by ultrasound/echocardiography that are an established indication for CMA, especially when extracardiac anomalies or septal defects are present.

GDD/ID -> Global Developmental Delay / Intellectual Disability; failure to meet expected developmental milestones in multiple domains (GDD for children <5 years) or intellectual disability characterized by deficits in intellectual and adaptive functioning; CMA is recommended as a first-tier genetic test for nonsyndromic presentations.

ASD -> Autism Spectrum Disorder; a neurodevelopmental disorder marked by persistent difficulties in social communication and restricted, repetitive behaviors; CMA is an indicated genetic test per professional guidance for etiologic evaluation.

Congenital Anomaly -> A physical developmental defect present at birth and identified within the first twelve months; the updated terminology in this policy replaces prior references to 'multiple anomalies' with 'Multiple Congenital Anomalies' to align with current definitions.

Revision History

06/01/2026revisedLatest

Added reference link to the Medical Policy titled 'Genetic Testing for Cardiac Disease' and removed two other policy links.

06/01/2026revisedLatest

Updated Coverage Rationale terminology: replaced 'Multiple anomalies' with 'Multiple Congenital Anomalies' and 'Developmental Delay' with 'Global Developmental Delay'.

06/01/2026

Policy Summary

PayerColorado Rocky Mountain Health Plans

PolicyChromosomal microarray (CMA) testing (prenatal, stillbirth, pediatric indications)

Policy CodePolicy N/A

Change TypeTerminology, definitions, and reference link updates

Effective Date

Next Review Date

Key ActionDocument the clinical indication on the requisition and in the medical record to support CMA ordering and potential coverage.

SourceLink

On This Page

Documentation Required

Phenotype-driven test selection

Consider clinical guidelines and phenotype-driven test selection: Use established clinical guidelines and the patient’s phenotype to choose the most appropriate assay. For individuals with a well-defined, syndromic presentation consider targeted testing when available; for nonspecific developmental delay, multiple congenital anomalies, or when broad detection of copy-number variants and regions of homozygosity is needed, consider genome‑wide CMA (aCGH or SNP array) or other genome-wide methods.

Document rationale for selecting targeted versus genome‑wide testing tied to clinical features.
Reference specialty guidelines when applicable to support test selection.

Prior Authorization

Prior authorization / coverage evaluation for Medicare Advantage members

Prior authorization and coverage evaluation for Medicare Advantage members: Verify coverage and PA requirements against applicable Medicare National Coverage Determination (NCD) and Local Coverage Determinations (LCDs) for Medicare Advantage plans and apply the plan’s PA rules.

Check applicable Medicare NCD/LCDs for molecular/cytogenomic testing when the member is enrolled in Medicare Advantage.
Apply the specific payer/plan PA process and document authorizations obtained.

Documentation Required

Reference member benefit plan and mandates

Use member-specific benefit plan: Reference the member’s benefit plan, certificate, and any applicable state or federal mandates to determine coverage, required documentation, and any plan-specific testing limitations prior to ordering CMA.

Confirm benefit coverage, medical necessity criteria, and any testing frequency or provider network requirements.
Retain documentation of benefit verification in the medical record.