How does being rhesus negative effect my pregnancy?

What does rhesus negative mean?

Many of us don't know our blood type before becoming pregnant so at your first midwife appointment they will test this for you (amongst other things). Most people are rhesus-D positive, which means the surface of their red blood cells contains a protein called the D antigen. But around 15% of people in the UK are rhesus negative, known as RhD negative (Source: Mumsnet).



Please note any of the following information should not replace that of your medical practioner. Please consult them if you have any questions about your health care or that of your baby

How does it affect me?

Once you have your blood test results your midwife will tell you if you are rhesus negative or not. If you are rhesus negative don't panic - we are going to go through what kind of care you should expect and why.

You will need injections during your pregnancy called Anti-D. The frequency and amount varies depending on where you are in the country, but it is usual to have at least one injection during pregnancy.

The most common way of having this injection is in the top of your thigh or buttocks. Your midwife will ask you to lay down for this on your side, and may also ask you to wiggle your feet. Though you may feel slightly silly doing this, I would recommend you do it anyway. When I had my anti-d injection I found this helped releive the pain (yes unfortunately this injection can be a little painful).

Depending where you are in the country you may have a second or even third injection of anti-d. But you may also have an injection after birth. The midwife, nurse or doctor will take blood samples shortly after birth from you and the umbilical cord. This will be then tested for the D antigen - if your baby is rhesus positive, then you will need another anti-D injection within 72 hours.

Why do I need these injections?

These injections are important incase your baby has rhesus positive blood from their father - this would make your blood and the baby's blood incompatiable. If your blood then comes into contact with the baby's blood, then an immune response is triggered. Your body will then develop antibodies that fight against your baby's blood which is known as sensitisation.

It is very unusual for your blood and the baby's blood to mix during pregnancy (although this risk increases with each subsequent pregnancy), and sensitisation doesn't normally occur until after birth. The likihood of you having a sensitisation event increases when there is:

• Bleeding during pregnancy
• Invasive procedures such as an amniocentesis or CVS
• Abdominal injury during pregnancy
• External cephalic version (where the baby is turned in the later stages of pregnancy)
• Misscarriage
• Ectopic pregnancy
• Termination
• Blood transfusions

If you are rhesus negative it is important to carry a card or wristband around with you at all times so that if you are to fall, paramedics and doctors would be aware you needed an additional anti-D injection - this helps to limit the chances of having a sensitisation event. Anti-D neutralises the D antigen in foetal blood so your blood does not detect it and produce antibodies to fight it.




Once the antibodies are created in your body they won't leave, so having anti-d injections help to protect future pregnancies as they can cross the placenta and attack the babys blood cells. When this happens it is known as rhesus disease - it can be mild and cause anaemia, but it can also be very serious causing haemolytic disease to the baby which can be fatal.

I myself am rhesus negative so I know it can sound rather scary. At the end of the day it is your own personal choice if you would like the anti-D injections - but for my own peace of mind I felt the few seconds of embarrassment outweighed anything else. My children were both rhesus negative anyway so I didnt need to have the additional injection after birth, but it is something I would still recommend mums to think about - even if they know their partner is rhesus negative.

 

If you would like to talk about being rhesus negative, rhesus disease, or any other issues that may have been raised from this blog post, please contact us team@nurturingnatalsupport.co.uk