Ordering Recommendation

Use to determine fetal RHD copy number(s) and assess the risk of alloimmune hemolytic disease. This test does not identify or distinguish between partial and weak RHD genotypes. For parental or neonatal testing, refer to RhD (RHD) Copy Number (0051368).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Amniotic fluid
OR cultured amniocytes OR cultured CVS: Two T-25 flasks at 80 percent confluency.
AND whole blood for maternal cell contamination: Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B).

If the client is unable to culture, order test Cytogenetics Grow and Send (ARUP test code 0040182) in addition to this test and ARUP will culture upon receipt (culturing fees will apply). If you have any questions, contact ARUP's Genetics Processing at 800-522-2787 ext. 3301.

Specimen Preparation

Amniotic fluid: Transport 10 mL amniotic fluid in a sterile container (Min: 5 mL) OR cultured amniocytes OR cultured CVS: Fill with culture media. Backup cultures must be retained at the client's institution until testing is complete.
Whole blood for maternal cell contamination: Transport 3 mL whole blood (Min: 1 mL)

Storage/Transport Temperature

Amniotic fluid, cultured amniocytes and cultured CVS: CRITICAL TEMPERATURE. Must be received within 48 hours of shipment due to lability of cells.
Whole blood for maternal cell contamination: Refrigerated.

Unacceptable Conditions

Frozen specimens in glass collection tubes.

Remarks

Patient History Form is available on the ARUP website or by contacting ARUP Client Services.

Stability

Fetal Specimens: Ambient: 48 hours; Refrigerated: 48 hours; Frozen: Unacceptable
Whole blood for maternal cell contamination: Ambient: 72 hours; Refrigerated: 1 week; Frozen: 1 month

Methodology

Polymerase Chain Reaction (PCR)/Fluorescence Monitoring/Fragment Analysis

Performed

Varies

Reported

2-7 days

Reference Interval

By report

Interpretive Data

Refer to report.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Compliance Category

Laboratory Developed Test (LDT)

Note

Hotline History

N/A

CPT Codes

81403; 81265 Fetal Cell Contamination (FCC)

Components

Component Test Code* Component Chart Name LOINC
0050548 Maternal Contamination Study Fetal Spec 59266-7
0050612 Maternal Contam Study, Maternal Spec 66746-9
3016641 RhD Gene (RHD) Copy Number, Fetal Spec 31208-2
3016642 RhD Gene (RHD) Copy Number Fetal, Interp 50398-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • RHD Gene
  • RHD genotyping
RhD Gene (RHD) Copy Number, Fetal