‘Knowing your rhesus status can save life ’
What is Rhesus factor?
Rhesus factor is an antigen on the surface of red blood cells.
Apart from the A, B, O classifications, where we have blood groups A, B, AB and O, the rhesus system is another important classification of blood group in human beings.
Simply put, people are either Rhesus positive or negative, depending on the presence or absence of the Rhesus factor present in their red blood cells respectively.
This Rhesus factor is inherited from parents, so a man or woman who is Rhesus negative may have one or more children, who are also Rhesus negative, even if their spouse is Rhesus positive.
How important is it to know about Rhesus factor and how does it improve one’s health?
Knowing your blood group is very important and could even be life-saving at times.
In times of emergency, where a lot of donors of a particular blood group are needed, those who know their blood group could help to hasten the process and maximise resources that would have been used to screen hundreds of others.
In addition, pregnant women, who are Rhesus negative may have certain tests, drugs and interventions to undergo to ensure the best pregnancy outcome and optimise their reproductive potential for the future.
When does it pose a threat to human life?
It poses a threat to human life in cases of blood transfusion, where incompatible blood is transfused to a Rhesus negative woman and she becomes sensitised or if she gets sensitised by other means, especially during pregnancy or delivery or where Rhesus positive blood from the baby is transferred to the mother.
If she is pregnant subsequently with a foetus that is Rhesus positive, her immune system that has been primed by prior sensitisation would have produced antibodies to fight against the foetus, which they perceive as foreign or as an invader.
This production of antibodies is called Rhesus isoimmunisation. Such a woman would be at a risk of having recurrent miscarriages in future pregnancies with Rhesus positive foetuses.
At what point should Rhesus factor identification come in?
People should know their blood groups as well as the A, B, O and rhesus classifications from childhood. People could be A positive, O negative, AB positive and so on.
This is very important because emergencies can arise at any point.
It also has more implication for women, who are Rhesus negative and have Rhesus positive partners.
When a woman with a Rhesus negative blood group and a Rhesus positive partner gets pregnant, what steps should she take?
She should book the pregnancy in an appropriate health facility for proper management.
She would need to do tests to determine if she has already been sensitised in the past and started producing antibodies as this could affect the wellbeing of her foetus.
She would also be told if and when she needs to take immunoglobulin injections.
These injections help to mop up antigens that would have elicited the production of antibodies, where it is said the woman has been sensitised.
They would need to be taken as soon as possible after delivery but may also be needed at other points as prescribed by the doctor.
These injections are important but relatively expensive, so discussions about them are a necessity during the antenatal period.
It is important for every woman, who is pregnant, to book for antenatal care as early as possible.
This is particularly necessary in women with risk factors, such as the Rhesus negative blood group.
Her pregnancy should be registered under the care of a competent obstetrician for the best pregnancy outcome. The blood group of a person remains constant from birth and does not change.
Some hospitals do not engage patients on Rhesus factor discussions, what is your take?
It is very important that pregnant women are aware of their blood group.
Those who were not previously aware should be informed when they present for antenatal care.
Routinely, all pregnant women should have some tests done when they register for antenatal care.
The blood group is one of these tests that should be done and the results should be discussed with the woman.
Those who are Rhesus negative would have further counselling to explain the meaning and further steps that need to be taken to prevent adverse pregnancy outcome.
Will you agree with me that it is responsible for childlessness and miscarriages in marriage?
I agree with you that Rhesus isoimmunisation could be a cause of subfertility and recurrent miscarriages.
Although the proportion of these in the overall picture of those with subfertility/infertility is relatively small.
These statistics are not helpful to a couple, who have lost up to four pregnancies to this condition when they are desirous of children and live in an environment where a premium is placed on having children in marriage. As a matter of fact, it can be very devastating.
What is the way out? Is there a permanent solution?
Prevention is better than cure. Everybody should be aware of his or her blood group.
Antenatal care should be accessible and affordable to all pregnant women regardless of their place of residence, social, educational or marriage status.
Women who are pregnant should register for antenatal care under the care of competent health professionals as early as possible so that those who are rhesus negative would be properly managed to prevent them from being sensitized or immunized as this could lead to adverse pregnancy outcome like miscarriages, preterm deliveries and stillbirths.
A Rhesus negative mother will be given a shot of Rh immunoglobulin (RhIg); this is made from donated blood and is given around the 28th week of pregnancy to prevent Rh sensitisation for the rest of the pregnancy, also within 72 hours after the delivery of an Rh-positive infant or after a miscarriage, abortion, or ectopic pregnancy.
Women who are Rh negative, who have kept up to date with recommended RhoGAM shots and who do not have antibodies against Rhesus factor do not face increased risk for pregnancy loss due to having Rhesus negative blood.
Studies in Nigeria have shown that most people are Rhesus positive.
Rhesus negative people are just about five per cent or less of our population as compared to up to 15 per cent in Caucasians.
So they are relatively fewer in our environment.
If there is an emergency like massive bleeding, where someone who is Rhesus negative loses a lot of blood that has to be replaced as soon as possible, this may become a challenge. The blood banking services are not ideal and there is a paucity of Rhesus negative blood.
Those who are ‘O’ negative can donate blood to all other blood groups so they are regarded as universal donors.
They can, however, only receive blood from those who are ‘O’ negative.
Therefore, people are encouraged to donate blood voluntarily as often as two to three times a year so that those who need it can get it and they too would get when they need it.