O Neg blood group and 2nd pregnancy

[roobarbncustard]

Hi,

I found out during my first pregnancy that my blood group is O Neg. I had the anti D at 28 weeks and when my son was born he was O neg too so I didn't need another one.

I don't know my DH's blood group, but if my son is O neg does this mean his father must be too or if I have a 2nd baby could that be O positive? I'm trying to get pregnant again and have just been doing a bit of research as to whether my blood group may affect the viability of a 2nd pregnancy.

Thanks.

RnC

No the father's blood group isn't necessarily o neg.
You'll have the anti-d again.

Hi. I'm O-neg too and my dh is O+. All my dcs are O+ except one who is also O-neg. The consultant told me that my dh need only have recessive O-neg gene for there to be the chance of baby being O-neg. Hope this helps.

No, dp is + both dcs and I are all -, have never had anti-D.

Thanks so much, I've scoured the internet looking for an answer to this and you've come back so quickly - much appreciated! It's all quite confusing this blood group business, it was quite a surprise to discover that I'm O neg as my father, mother and sister are all O positive.

Do I need to speak to a doc about getting pregnant again or will the anti D that I had a couple of years ago cover me while I'm ttc?

You should have no issues with your next pregnancy as your first baby was also O-neg but anti D will need to be taken in case dc2 is O+ to prevent problems in hypothetical pregnancy no. 3.

Anti-d is not for the current pregnancy but to prevent problems in future pregnancies. Hope this makes sense. Anyway you'll have your blood group checked in every pregnancy.

You won't need anti-D while you're ttc. You only need it after any foetus you are carrying reaches 12w, because that's when the foetal blood cells start to develop the D antigen on their surfaces.
As your first DS was Rh D Neg, then he had no D antigen on his blood cells, so any leakage of cells from him to you would have no impact on your blood, i.e. you would not have made any anti-D yourself.

The anti-D you are given in pregnancy is prophylactic - it is there to stop you making anti-D yourself should any bloodcells from a RhD positive baby cross into your blood stream (happens sometimes). Mostly it won't affect the current pg, but could affect later pgs.

It is quite possible for you to be O RhD Neg where your parents are both O RhD pos - as someone has already said, RhD Neg is a recessive state, so your parents would have one positive gene and one negative gene each. You got the negative gene from each of them; your sister got a positive gene from one or both of your parents.

You will always be offered anti-D prophylaxis while pregnant because you are RhD neg and the cord blood will always be tested once the baby is born, regardless of your DH's blood group - because there are cases where the husband is not the father. Even if you swear blue that he is, they'll still check. Not because they don't believe YOU, but because they have to.

Thumbwitch and Jan36 - thank you. It never occurred to me that with the first ankle biter being negative would mean there would be no impact on my blood, that makes sense now that you've explained it. I've scoured no end of websites and nowhere has explained it as succinctly as here.

Well, that's one area I can stop worrying about and get on with the job in hand, so to speak! Keeping my fingers crossed for a September baby.....

Just to add - if your DH is definitely Rh D Neg, as are you, then there is almost no way that any baby you produce will be Rh D pos, as neither of you have that gene. But you'll still get the anti-D shot offered anyway because strange things do happen occasionally. :)

Sorry, misremembered your opening post - your DH could easily be RhD pos, like your parents, with one positive and one negative gene - and he passed on the negative gene to your DS. But if he is positive, then your next baby has a 50:50 chance of being Rh D positive as well. Just so you know.

Good luck roobarb.

I'm also O neg and have had anti-d in all 3 of my pregnancies. I have no idea what blood type my dh is but dd is O pos and ds is O neg, not sure about this one as not been born yet! It has never affected viability of my pregnancies if that helps? Anti-d does sting like a bitch though!

ha, that reminds me of when I had my anti-D shots - they warned me it would probably sting quite a lot, but tbh it was nothing like as bad as my daily Clexane shots! They were fuckers - nothing initially but then you'd get the afterburn...
In fact, the anti-D shot didn't really register on my pain scale at all, phew! :)