Aborhbldmother
A blood test during pregnancy to determine the mother's blood type (ABO) and Rh factor, important for preventing complications during pregnancy and delivery.
{"Determines if the mother is type A, B, AB, or O","Identifies whether the mother is Rh positive or Rh negative","Helps prevent dangerous blood incompatibilities between mother and baby","Rh-negative mothers may need Rh immunoglobulin injections","This test is routine during prenatal care"}
Key facts at a glance
- LOINC
- 90905-1
- Short code
- ABO + Rh Bld Mother
- Synonyms
- ABO + Rh Bld Mother
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test?
The Mother's ABO and Rh Blood Type test is a routine blood test performed during pregnancy. It determines two important things about your blood: (1) your ABO blood type (A, B, AB, or O), and (2) whether you have the Rh factor (a protein on red blood cells). You are either Rh positive (have the factor) or Rh negative (do not have the factor).
Why is this test important during pregnancy?
Knowing your blood type is crucial for a safe pregnancy. If you are Rh negative and your baby is Rh positive, your immune system may produce antibodies that attack the baby's red blood cells. This condition, called Rh incompatibility, can cause serious health problems for your baby, including anemia, jaundice, or even stillbirth. The good news is that this can be prevented with proper monitoring and treatment.
How is the test done?
A healthcare provider will draw a small blood sample from your arm, usually during your first prenatal visit. The blood is sent to a laboratory where it is tested to determine your ABO type and Rh status. The results are typically available within a day or two.
What happens if I am Rh negative?
If you are Rh negative, your doctor will monitor you closely throughout your pregnancy. You may receive Rh immunoglobulin (Rhogam) injections at around 28 weeks of pregnancy and within 72 hours after delivery if your baby is Rh positive. This prevents your body from developing harmful antibodies that could affect future pregnancies.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Does it hurt?
Do I need to fast before this test?
What if I don't know my blood type?
Can my blood type change?
Will this test hurt my baby?
Sources
- 1
- 2
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy