This post has been quite long in the making – over two years to be exact. I found out that I am rhesus negative when, at age 26, I had routine blood work done at the start of pregnancy. Whilst it came as a surprise, I didn’t really ponder about it much. Until Week 16 that is.
Week 16 was characterised by a fall courtesy of heels, pelvic instability, and Dutch cobblestones. It was cold, so my hands were warmly tucked in my coat pockets. My heel got stuck and I tumbled straight onto my (big) baby bump. That was the first time I felt Katrin kick: three times, to be exact. We rushed to the ER (at midnight), and that’s where my rhesus negative blood started to matter.
Of course, what happened that night led to a whole lot of Google – and worry. As I now know that Rhesus Negative blood is very common on our islands, I collated all that I found out to make it easier for all of you fellow rhesus negative mums and mums-to-be.
What is rhesus negative?
Just as there are a number of different blood groups (such as A, B, AB, and O), there is also the Rh factor. Basically, the Rh factor is a protein that is usually present on the surface of red blood cells. If you have this Rh factor, then you’re Rh positive. If not, then you’re Rh negative.
Why am I Rh negative?
Well. That is a question that many have tried answering, with some also theorising that aliens had something to do with it. Only about 15% of people are Rh negative, with our origins going back to the Basque region. Dr. Luigi Cavalli-Sforza who studied populations with Rh-negative blood notes that the highest percentage of people with Rh-negative blood can be found in the Atlas Mountains of Morocco (40%), and 25% amongst Basques.
Bottom line is, your Rh factor is inherited. This does not mean that your baby will also be Rhesus negative though. And this is where issues can crop up.
Rhesus negative and pregnancy
Problems may arise if you are rhesus negative and your baby is rhesus positive. This is known as Rh incompatibility. Normally, there are no issues with a first pregnancy; it’s during a second pregnancy that it can become more of a problem. Basically, when the mother’s Rh negative blood comes into contact with the baby’s Rhesus positive blood, it causes the mother to make antibodies against the baby’s rhesus, fighting it as if it were something harmful.
During pregnancy, mum’s and baby’s blood do not mix. But, blood may cross the placenta into the mum during labor and birth, or if amniocentesis, chorionic villus sampling (CVS), bleeding, manual rotation of a breech baby, or, as in my case, a fall shielded by a pregnant tummy, are experienced.
How will I know if my body is producing antibodies against the baby?
A blood test will be carried out to check if you have developed antibodies to Rh-positive blood. If you have, you will be monitored. If these antibodies get high, more tests are done to further monitor your baby.
How can I prevent health scares if I am rhesus negative?
The Anti-D injection is given routinely to all rhesus negative mums-to-be at 28-30 weeks, and then again right after birth. The Anti-D prevents the production of antibodies that fight the baby. Once born, the baby’s blood type and rhesus will be checked.
Rhesus negative and a second pregnancy
As we’ve seen, having rhesus negative blood is not much of a concern during a first pregnancy. With a second pregnancy though, your antibodies can attack the red blood cells of a rhesus-positive baby. This can lead to anaemia and jaundice. And this is why the Anti-D injection is important.
Hope this helps!
BabyCentre (of course)
The American Congress of Obstetricians and Gynecologists
http://www.megalithic.co.uk (for the genealogy part)