Part of
Blood Type
Rhesus Factor
Rhesus factor is a protein on red blood cells that determines if blood type is positive or negative.
Rhesus Factor
Normal range
Normal range
Positive, Negative
Positive, Negative
Normal range
Positive, Negative
Positive, Negative
Normal range
Rhesus Factor
Rhesus Factor
Rhesus factor is a protein on red blood cells that determines if blood type is positive or negative.
Rhesus Factor
Normal range
Positive, Negative
Normal range
Positive, Negative
Positive, Negative
Normal range
Rhesus Factor
Rhesus Factor
Rhesus factor is a protein on red blood cells that determines if blood type is positive or negative.
Rhesus Factor
Normal range
Positive, Negative
Normal range
Positive, Negative
Positive, Negative
Normal range
Rhesus Factor
Rhesus Factor
Rhesus factor is a protein on red blood cells that determines if blood type is positive or negative.
Rhesus Factor
Normal range
Positive, Negative
Normal range
Positive, Negative
Positive, Negative
Normal range
Rhesus Factor
Dr. Yiannis Balanos
MBBS MRCGP
Your Blood's Second Identity Marker
Your Blood's Second Identity Marker
Your Blood's Second Identity Marker
The Rhesus factor, specifically the RhD antigen, is the second most important blood group system after ABO. This genetic characteristic determines whether you are RhD positive (you have the RhD antigen on your red blood cells) or RhD negative (you don't have it). In the UK, around 85% of people are RhD positive and 15% are RhD negative. Your Rhesus status is inherited from your parents and remains constant throughout your life, playing a particularly important role during pregnancy and in blood transfusions.
Unlike the ABO system where people naturally have antibodies against blood groups they don't possess, RhD negative people don't automatically have antibodies against RhD positive blood. However, they can develop these antibodies if exposed to RhD positive blood, which is why Rhesus status is especially important during pregnancy.
The Rhesus factor, specifically the RhD antigen, is the second most important blood group system after ABO. This genetic characteristic determines whether you are RhD positive (you have the RhD antigen on your red blood cells) or RhD negative (you don't have it). In the UK, around 85% of people are RhD positive and 15% are RhD negative. Your Rhesus status is inherited from your parents and remains constant throughout your life, playing a particularly important role during pregnancy and in blood transfusions.
Unlike the ABO system where people naturally have antibodies against blood groups they don't possess, RhD negative people don't automatically have antibodies against RhD positive blood. However, they can develop these antibodies if exposed to RhD positive blood, which is why Rhesus status is especially important during pregnancy.
Understanding RhD Positive and RhD Negative
Understanding RhD Positive and RhD Negative
Understanding RhD Positive and RhD Negative
Understanding RhD Positive and RhD Negative
Discover what it means to be RhD positive or negative and how this genetic trait is inherited from your parents.
Read more
Why Rhesus Status Matters in Pregnancy
Why Rhesus Status Matters in Pregnancy
Why Rhesus Status Matters in Pregnancy
Why Rhesus Status Matters in Pregnancy
Learn about rhesus disease and why RhD status is important for pregnant women and their babies' health.
Read more
Prevention and Treatment
Prevention and Treatment
Prevention and Treatment
Prevention and Treatment
Explore how modern medicine prevents rhesus disease through anti-D immunoglobulin and routine screening during pregnancy.
Read more
Understanding Your Rhesus Status Test
Understanding Your Rhesus Status Test
Understanding Your Rhesus Status Test
Understanding Your Rhesus Status Test
Find out when Rhesus testing is performed and what your results mean for your healthcare.
Read more
Understanding RhD Positive and RhD Negative
The RhD factor is a molecule found on the surface of red blood cells. People who have the RhD antigen are RhD positive, and those without it are RhD negative. This characteristic is determined by genes inherited from your parents and cannot change throughout your life.
If you're RhD positive, you have the RhD antigen on your red blood cells. This is the more common status and generally doesn't cause any health concerns. Most people are RhD positive and never need to think about it outside of blood donation or pregnancy.
If you're RhD negative, you lack the RhD antigen on your red blood cells. This is less common but equally normal. Being RhD negative doesn't cause any health problems in daily life, but it becomes medically important in two main situations: during pregnancy and when receiving blood transfusions.
Your Rhesus status is typically written alongside your ABO blood group—for example, "O positive" means blood group O with RhD positive status, whilst "A negative" means blood group A with RhD negative status. O positive is the most common blood type overall, with about 35% of the UK population having this combination.
Understanding RhD Positive and RhD Negative
The RhD factor is a molecule found on the surface of red blood cells. People who have the RhD antigen are RhD positive, and those without it are RhD negative. This characteristic is determined by genes inherited from your parents and cannot change throughout your life.
If you're RhD positive, you have the RhD antigen on your red blood cells. This is the more common status and generally doesn't cause any health concerns. Most people are RhD positive and never need to think about it outside of blood donation or pregnancy.
If you're RhD negative, you lack the RhD antigen on your red blood cells. This is less common but equally normal. Being RhD negative doesn't cause any health problems in daily life, but it becomes medically important in two main situations: during pregnancy and when receiving blood transfusions.
Your Rhesus status is typically written alongside your ABO blood group—for example, "O positive" means blood group O with RhD positive status, whilst "A negative" means blood group A with RhD negative status. O positive is the most common blood type overall, with about 35% of the UK population having this combination.
Understanding RhD Positive and RhD Negative
The RhD factor is a molecule found on the surface of red blood cells. People who have the RhD antigen are RhD positive, and those without it are RhD negative. This characteristic is determined by genes inherited from your parents and cannot change throughout your life.
If you're RhD positive, you have the RhD antigen on your red blood cells. This is the more common status and generally doesn't cause any health concerns. Most people are RhD positive and never need to think about it outside of blood donation or pregnancy.
If you're RhD negative, you lack the RhD antigen on your red blood cells. This is less common but equally normal. Being RhD negative doesn't cause any health problems in daily life, but it becomes medically important in two main situations: during pregnancy and when receiving blood transfusions.
Your Rhesus status is typically written alongside your ABO blood group—for example, "O positive" means blood group O with RhD positive status, whilst "A negative" means blood group A with RhD negative status. O positive is the most common blood type overall, with about 35% of the UK population having this combination.
Understanding RhD Positive and RhD Negative
The RhD factor is a molecule found on the surface of red blood cells. People who have the RhD antigen are RhD positive, and those without it are RhD negative. This characteristic is determined by genes inherited from your parents and cannot change throughout your life.
If you're RhD positive, you have the RhD antigen on your red blood cells. This is the more common status and generally doesn't cause any health concerns. Most people are RhD positive and never need to think about it outside of blood donation or pregnancy.
If you're RhD negative, you lack the RhD antigen on your red blood cells. This is less common but equally normal. Being RhD negative doesn't cause any health problems in daily life, but it becomes medically important in two main situations: during pregnancy and when receiving blood transfusions.
Your Rhesus status is typically written alongside your ABO blood group—for example, "O positive" means blood group O with RhD positive status, whilst "A negative" means blood group A with RhD negative status. O positive is the most common blood type overall, with about 35% of the UK population having this combination.
Why Rhesus Status Matters in Pregnancy
Rhesus status becomes particularly important during pregnancy when the mother is RhD negative and the baby is RhD positive (inherited from an RhD positive father). Rhesus disease, also called haemolytic disease, is a condition where antibodies in a pregnant woman's blood attack the baby's blood cells.
This can happen if some of the baby's RhD positive blood enters the mother's bloodstream during pregnancy or birth. The mother's immune system may recognise the RhD antigen as foreign and produce antibodies against it. Whilst this typically doesn't affect the first pregnancy significantly, these antibodies can remain in the mother's system and potentially cause problems in future pregnancies with RhD positive babies.
Rhesus disease can cause a baby to have anaemia and jaundice. In severe cases, it can lead to more serious complications. However, with modern screening and prevention, rhesus disease has become rare in the UK.
It's important to note that rhesus disease only occurs when the mother is RhD negative and the baby is RhD positive. If both parents are RhD negative, all their children will be RhD negative and there's no risk of rhesus disease. Similarly, if the mother is RhD positive, rhesus disease cannot occur regardless of the baby's Rhesus status.
Why Rhesus Status Matters in Pregnancy
Rhesus status becomes particularly important during pregnancy when the mother is RhD negative and the baby is RhD positive (inherited from an RhD positive father). Rhesus disease, also called haemolytic disease, is a condition where antibodies in a pregnant woman's blood attack the baby's blood cells.
This can happen if some of the baby's RhD positive blood enters the mother's bloodstream during pregnancy or birth. The mother's immune system may recognise the RhD antigen as foreign and produce antibodies against it. Whilst this typically doesn't affect the first pregnancy significantly, these antibodies can remain in the mother's system and potentially cause problems in future pregnancies with RhD positive babies.
Rhesus disease can cause a baby to have anaemia and jaundice. In severe cases, it can lead to more serious complications. However, with modern screening and prevention, rhesus disease has become rare in the UK.
It's important to note that rhesus disease only occurs when the mother is RhD negative and the baby is RhD positive. If both parents are RhD negative, all their children will be RhD negative and there's no risk of rhesus disease. Similarly, if the mother is RhD positive, rhesus disease cannot occur regardless of the baby's Rhesus status.
Why Rhesus Status Matters in Pregnancy
Rhesus status becomes particularly important during pregnancy when the mother is RhD negative and the baby is RhD positive (inherited from an RhD positive father). Rhesus disease, also called haemolytic disease, is a condition where antibodies in a pregnant woman's blood attack the baby's blood cells.
This can happen if some of the baby's RhD positive blood enters the mother's bloodstream during pregnancy or birth. The mother's immune system may recognise the RhD antigen as foreign and produce antibodies against it. Whilst this typically doesn't affect the first pregnancy significantly, these antibodies can remain in the mother's system and potentially cause problems in future pregnancies with RhD positive babies.
Rhesus disease can cause a baby to have anaemia and jaundice. In severe cases, it can lead to more serious complications. However, with modern screening and prevention, rhesus disease has become rare in the UK.
It's important to note that rhesus disease only occurs when the mother is RhD negative and the baby is RhD positive. If both parents are RhD negative, all their children will be RhD negative and there's no risk of rhesus disease. Similarly, if the mother is RhD positive, rhesus disease cannot occur regardless of the baby's Rhesus status.
Why Rhesus Status Matters in Pregnancy
Rhesus status becomes particularly important during pregnancy when the mother is RhD negative and the baby is RhD positive (inherited from an RhD positive father). Rhesus disease, also called haemolytic disease, is a condition where antibodies in a pregnant woman's blood attack the baby's blood cells.
This can happen if some of the baby's RhD positive blood enters the mother's bloodstream during pregnancy or birth. The mother's immune system may recognise the RhD antigen as foreign and produce antibodies against it. Whilst this typically doesn't affect the first pregnancy significantly, these antibodies can remain in the mother's system and potentially cause problems in future pregnancies with RhD positive babies.
Rhesus disease can cause a baby to have anaemia and jaundice. In severe cases, it can lead to more serious complications. However, with modern screening and prevention, rhesus disease has become rare in the UK.
It's important to note that rhesus disease only occurs when the mother is RhD negative and the baby is RhD positive. If both parents are RhD negative, all their children will be RhD negative and there's no risk of rhesus disease. Similarly, if the mother is RhD positive, rhesus disease cannot occur regardless of the baby's Rhesus status.
Prevention and Treatment
Modern medicine has made rhesus disease largely preventable through a treatment called anti-D immunoglobulin (also known as anti-D). This treatment protects RhD negative mothers from making antibodies against their baby's blood, and has been common practice in the UK for more than 20 years.
During pregnancy, all women have a blood test to find out their blood group and Rhesus status, typically at the initial booking appointment. If you're RhD negative, you'll be offered anti-D injections at specific times during pregnancy (usually around 28 weeks) and after birth if your baby is confirmed to be RhD positive.
NICE recommends non-invasive prenatal testing to determine the baby's RhD status using cell-free fetal DNA from the mother's blood. This test can identify whether the baby is RhD positive or negative, helping to guide whether anti-D treatment is needed.
If the baby is confirmed as RhD positive, non-sensitised women who are RhD negative should be offered postnatal anti-D immunoglobulin within 72 hours of birth. Anti-D may also be offered after certain events during pregnancy that might cause the baby's blood to mix with the mother's, such as amniocentesis, miscarriage, or abdominal trauma.
Prevention and Treatment
Modern medicine has made rhesus disease largely preventable through a treatment called anti-D immunoglobulin (also known as anti-D). This treatment protects RhD negative mothers from making antibodies against their baby's blood, and has been common practice in the UK for more than 20 years.
During pregnancy, all women have a blood test to find out their blood group and Rhesus status, typically at the initial booking appointment. If you're RhD negative, you'll be offered anti-D injections at specific times during pregnancy (usually around 28 weeks) and after birth if your baby is confirmed to be RhD positive.
NICE recommends non-invasive prenatal testing to determine the baby's RhD status using cell-free fetal DNA from the mother's blood. This test can identify whether the baby is RhD positive or negative, helping to guide whether anti-D treatment is needed.
If the baby is confirmed as RhD positive, non-sensitised women who are RhD negative should be offered postnatal anti-D immunoglobulin within 72 hours of birth. Anti-D may also be offered after certain events during pregnancy that might cause the baby's blood to mix with the mother's, such as amniocentesis, miscarriage, or abdominal trauma.
Prevention and Treatment
Modern medicine has made rhesus disease largely preventable through a treatment called anti-D immunoglobulin (also known as anti-D). This treatment protects RhD negative mothers from making antibodies against their baby's blood, and has been common practice in the UK for more than 20 years.
During pregnancy, all women have a blood test to find out their blood group and Rhesus status, typically at the initial booking appointment. If you're RhD negative, you'll be offered anti-D injections at specific times during pregnancy (usually around 28 weeks) and after birth if your baby is confirmed to be RhD positive.
NICE recommends non-invasive prenatal testing to determine the baby's RhD status using cell-free fetal DNA from the mother's blood. This test can identify whether the baby is RhD positive or negative, helping to guide whether anti-D treatment is needed.
If the baby is confirmed as RhD positive, non-sensitised women who are RhD negative should be offered postnatal anti-D immunoglobulin within 72 hours of birth. Anti-D may also be offered after certain events during pregnancy that might cause the baby's blood to mix with the mother's, such as amniocentesis, miscarriage, or abdominal trauma.
Prevention and Treatment
Modern medicine has made rhesus disease largely preventable through a treatment called anti-D immunoglobulin (also known as anti-D). This treatment protects RhD negative mothers from making antibodies against their baby's blood, and has been common practice in the UK for more than 20 years.
During pregnancy, all women have a blood test to find out their blood group and Rhesus status, typically at the initial booking appointment. If you're RhD negative, you'll be offered anti-D injections at specific times during pregnancy (usually around 28 weeks) and after birth if your baby is confirmed to be RhD positive.
NICE recommends non-invasive prenatal testing to determine the baby's RhD status using cell-free fetal DNA from the mother's blood. This test can identify whether the baby is RhD positive or negative, helping to guide whether anti-D treatment is needed.
If the baby is confirmed as RhD positive, non-sensitised women who are RhD negative should be offered postnatal anti-D immunoglobulin within 72 hours of birth. Anti-D may also be offered after certain events during pregnancy that might cause the baby's blood to mix with the mother's, such as amniocentesis, miscarriage, or abdominal trauma.
Understanding Your Rhesus Status Test
Rhesus status testing is straightforward and performed as part of standard blood group testing. A small blood sample is taken and tested in a laboratory to determine whether the RhD antigen is present on your red blood cells.
Rhesus status is usually identified during the routine screening tests offered during pregnancy. Testing is also performed before blood transfusions, when registering as a blood donor, and sometimes before surgery where transfusion might be needed.
Your test result will indicate whether you are RhD positive or RhD negative. This information is recorded in your medical records and remains relevant throughout your life, though hospitals typically verify blood group and Rhesus status with a fresh sample before any transfusion.
If you're pregnant and RhD negative, your healthcare team will discuss the anti-D prevention programme with you and arrange appropriate monitoring and treatment throughout your pregnancy. You'll also be offered testing to determine your baby's RhD status, which helps guide whether postnatal anti-D treatment is necessary.
Understanding Your Rhesus Status Test
Rhesus status testing is straightforward and performed as part of standard blood group testing. A small blood sample is taken and tested in a laboratory to determine whether the RhD antigen is present on your red blood cells.
Rhesus status is usually identified during the routine screening tests offered during pregnancy. Testing is also performed before blood transfusions, when registering as a blood donor, and sometimes before surgery where transfusion might be needed.
Your test result will indicate whether you are RhD positive or RhD negative. This information is recorded in your medical records and remains relevant throughout your life, though hospitals typically verify blood group and Rhesus status with a fresh sample before any transfusion.
If you're pregnant and RhD negative, your healthcare team will discuss the anti-D prevention programme with you and arrange appropriate monitoring and treatment throughout your pregnancy. You'll also be offered testing to determine your baby's RhD status, which helps guide whether postnatal anti-D treatment is necessary.
Understanding Your Rhesus Status Test
Rhesus status testing is straightforward and performed as part of standard blood group testing. A small blood sample is taken and tested in a laboratory to determine whether the RhD antigen is present on your red blood cells.
Rhesus status is usually identified during the routine screening tests offered during pregnancy. Testing is also performed before blood transfusions, when registering as a blood donor, and sometimes before surgery where transfusion might be needed.
Your test result will indicate whether you are RhD positive or RhD negative. This information is recorded in your medical records and remains relevant throughout your life, though hospitals typically verify blood group and Rhesus status with a fresh sample before any transfusion.
If you're pregnant and RhD negative, your healthcare team will discuss the anti-D prevention programme with you and arrange appropriate monitoring and treatment throughout your pregnancy. You'll also be offered testing to determine your baby's RhD status, which helps guide whether postnatal anti-D treatment is necessary.
Understanding Your Rhesus Status Test
Rhesus status testing is straightforward and performed as part of standard blood group testing. A small blood sample is taken and tested in a laboratory to determine whether the RhD antigen is present on your red blood cells.
Rhesus status is usually identified during the routine screening tests offered during pregnancy. Testing is also performed before blood transfusions, when registering as a blood donor, and sometimes before surgery where transfusion might be needed.
Your test result will indicate whether you are RhD positive or RhD negative. This information is recorded in your medical records and remains relevant throughout your life, though hospitals typically verify blood group and Rhesus status with a fresh sample before any transfusion.
If you're pregnant and RhD negative, your healthcare team will discuss the anti-D prevention programme with you and arrange appropriate monitoring and treatment throughout your pregnancy. You'll also be offered testing to determine your baby's RhD status, which helps guide whether postnatal anti-D treatment is necessary.
The Takeaway
Your Rhesus status is a simple genetic characteristic that plays an important role in pregnancy care and blood transfusion safety. Being RhD negative is perfectly normal and doesn't cause any health problems in daily life, but requires specific care during pregnancy to prevent rhesus disease.
This simple blood test result, determined by genetics, remains one of the most important pieces of information in maternal and transfusion medicine.
The Takeaway
Your Rhesus status is a simple genetic characteristic that plays an important role in pregnancy care and blood transfusion safety. Being RhD negative is perfectly normal and doesn't cause any health problems in daily life, but requires specific care during pregnancy to prevent rhesus disease.
This simple blood test result, determined by genetics, remains one of the most important pieces of information in maternal and transfusion medicine.
The Takeaway
Your Rhesus status is a simple genetic characteristic that plays an important role in pregnancy care and blood transfusion safety. Being RhD negative is perfectly normal and doesn't cause any health problems in daily life, but requires specific care during pregnancy to prevent rhesus disease.
This simple blood test result, determined by genetics, remains one of the most important pieces of information in maternal and transfusion medicine.
The Takeaway
Your Rhesus status is a simple genetic characteristic that plays an important role in pregnancy care and blood transfusion safety. Being RhD negative is perfectly normal and doesn't cause any health problems in daily life, but requires specific care during pregnancy to prevent rhesus disease.
This simple blood test result, determined by genetics, remains one of the most important pieces of information in maternal and transfusion medicine.
References
NHS. (2024). Rhesus disease.
NHS. (2024). Blood groups.
NHS Blood and Transplant. (2024). Blood types.
NICE. (2021). Antenatal care. NICE guideline NG201.
Cambridge University Hospitals NHS Foundation Trust. (2024). Rhesus D (RhD) negative blood type: care in pregnancy and after birth.
References
NHS. (2024). Rhesus disease.
NHS. (2024). Blood groups.
NHS Blood and Transplant. (2024). Blood types.
NICE. (2021). Antenatal care. NICE guideline NG201.
Cambridge University Hospitals NHS Foundation Trust. (2024). Rhesus D (RhD) negative blood type: care in pregnancy and after birth.
References
NHS. (2024). Rhesus disease.
NHS. (2024). Blood groups.
NHS Blood and Transplant. (2024). Blood types.
NICE. (2021). Antenatal care. NICE guideline NG201.
Cambridge University Hospitals NHS Foundation Trust. (2024). Rhesus D (RhD) negative blood type: care in pregnancy and after birth.
References
NHS. (2024). Rhesus disease.
NHS. (2024). Blood groups.
NHS Blood and Transplant. (2024). Blood types.
NICE. (2021). Antenatal care. NICE guideline NG201.
Cambridge University Hospitals NHS Foundation Trust. (2024). Rhesus D (RhD) negative blood type: care in pregnancy and after birth.
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