Test Directory

Noninvasive Prenatal Screening for Fetal RhD

Specimen: Whole Blood

Collection Container: Streck Cell-Free BCT

Specimen Volume: 7-10 mL

*For Add-on requests:

• contact Genomics for add-on approval
• Genomics does not place add-on orders

1. Collect two Streck Cell-Free tubes. Note: If ordered with standard Cell-Free DNA (NIPT), no additional tubes need to be collected.
2. Draw blood using Vacutainer system (butterfly not appropriate); invert tube 10 times.
3. Specimen must be collected at or greater than 10 weeks gestational age.
4. For Add-on requests:

• contact Genomics for add-on approval
• Genomics does not place add-on orders

• Transport at room temperature.
• Do not freeze or expose to extreme temperatures.

• Specimen collected at <10 weeks gestation
• Improperly labeled specimen (minimum of two patient identifiers)
• Inappropriate specimen type
• Incomplete or incorrect test request form
• Insufficient volume
• Specimen has leaked in transit
• Specimen without a test order
• RhD-positive patient
• Twin/multiple pregnancy

• Fetal RhD
• RhD genotyping
• NIPT Fetal RhD

Noninvasive prenatal screening using cell-free DNA testing is currently the most sensitive and specific screening test for common fetal aneuploidies involving chromosomes 21, 18, 13, X, and Y with optional fetal sex detection and fetal RhD status. This test can be completed as early as 10 weeks gestational age. NIPS can provide expecting mothers the knowledge needed to make medical decisions regarding pregnancy, including the decision to pursue more invasive testing methods. NIPS is the best option for expecting patients to predict the likelihood of certain chromosome aneuploidies such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13), and sex chromosome aneuploidies. NIPS can also determine the fetal RhD status for RhD negative mothers, which helps to assess the risk of RhD incompatibility between mother and baby. NIPS is now endorsed by the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine for all patients, regardless of maternal age. This test is suitable for singleton and twin pregnancies and IVF with egg donor pregnancies (singleton and twin).