Rh Status

[Sregeem]

Hello--
I am 28 weeks pregnant and just went in for my diabetes screening. When they took blood, they needed 4 vials and when I looked at the sheet I saw they were testing not just glucose but also toxosomething, cbt, and rh something. I'm confused--I assumed I was rh positivie because I assumed I was tested for this back in the beginning. Why are they checking again? My mom and cousin are both negative, by the way. Does this mean I may in fact be negative? Just wondering what the implications are if so, since I've never had a shot or anything and am this far along.
Thanks!

[Elaine Brown, MD]

Hi!  
The first thing to do is ask your doctor what tests were done.  It is standard at 28 weeks to check glucose, blood count (CBC) and  an antibody screen for those who are rh negative.
You should find out if you are negative!  It is also helpful to know your blood type to.  I'm certain your doctor would be willing to tell you that information--why not?
For people who are rh positive, we administer rhogam at 28 weeks.  We give it later in the pregnancy so that we are sure to cover delivery.  The data shows that this is preferable.  We also give it after we test the antibody screen so that we don't get a false positive.
It never hurts to ask, you have every right to know your information!
Good luck!
Dr B

[TARA1178]

Hi!  I worked for many years in hospital laboratories, and with the blood bank department.  The wonderful lady above me here is correct.  When you go in to the doc in the beginning of your pregnancy, they did do an antibody screening.  I am assuming that ou came back positive, because they would have definately let you know back then if you were negative.  If you were negative, then you would indeed get a shot (Rhogam) at about 24-25 weeks, and then you would get another shot at birth, as well as the baby.  What they are testing for is to see if you have certain different types of antibodies in your blood.  They may have indeed tested you again, as some doctors may test at various times during pregnancy (however not all that frequently) because when you are pregnant, you may at anytime be exposed to different types of antibodies that you would then begin to carry.  When you are pregnant, your RH status can actually change at anytime, depending on what you are exposed to.  It's definately nothing I would worry about if I were you.  Good luck!

Tara

[momof8215]

If you are in fact rh- then you should have had a shot at 24 weeks. I don't know what the risks are after that time. The shot during the pregnancy is to protect the baby from your blood passing into him/her in case he/she is positive. After you give birth, they check the baby to see if they are + or -. If he/she is + then they have up to 72 hours to give you a shot. If they baby is - then you don't need the shot. I hope that was helpful. If you are rh+ then none of this applies to you anyway.  Good luck! :)