Fetal RHD Screen Invalid or Inconclusive
What the result means
An "Invalid" or "Inconclusive" Fetal RHD screening result means that the test could not tell if your baby is RhD positive or negative and determine if there is an RhD mismatch (incompatibility) between you and your baby.
Next steps
Your health-care provider may:
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- ask you to repeat the Fetal RHD screen, or
- treat your pregnancy as if your baby is RhD positive and recommend RhIG treatment.
In some cases, your health-care provider may recommend another blood test called maternal RHD genotyping. This test looks for normal variations in the RhD blood group, such as a weak D type or another RHD variant, which may explain why your blood test result was "Invalid" or "Inconclusive".
The results of this test can help your health-care provider determine whether you need RhIG during your pregnancy.
At delivery
A small blood sample will be collected from the umbilical cord to confirm your baby’s RhD status. The results may be used to guide your need for RhIG treatment after birth and may be shared with the testing laboratory for quality checks.
For Pregnant Individuals
Fetal RHD Screening Information Guide
Fetal RHD Screening Information Guide for Pregnant Individuals
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Virtual educational sessions on prenatal screening and nuchal translucency quality assurance are available upon request for health‑care providers.