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Insufficient Fetal DNA / Baby blood group testing

2 replies

Hyggeandhugs · 03/02/2022 21:20

At my 12wk scan the hospital did a blood test to check for chromosomal abnormalities (Downs, etc) and to find out my blood group.

We came out as low risk for chromosomal abnormality.

Because the blood test showed I was O Rh Negative, they then used the blood sample to try to work out baby's blood group, so that they could decide whether I need an Anti-D injection. It returned no result on the baby's blood group.

They took more blood at 18wks to again try and work out the baby's blood group, but again it's come back as no result. The midwife has said there was probably insufficient DNA in the sample (they took 3 vials!).

But here's why I'm panicking... if there's insufficient fetal DNA in my blood to work out baby's blood group (even at 18wks), surely there'd have been insufficient fetal DNA for the result of chromosomal abnormality test at 12wks to be reliable?

We also had a DNA based gender test done at 10wks. That said we were having a girl due to an absence of male DNA in my blood. At the 20wk scan they confirmed a girl, but now I'm doubting that too!

Does anyone have experience of having 'no result' on the baby blood group test, but reliable results for the other types of test?

Or maybe someone actually knows that you'd get told if there's insufficient fetal DNA for the chromosomal abnormalities test?

OP posts:
KTF367 · 05/02/2022 21:13

Not exactly the same but I had insufficient fetal DNA on a NIPT test but screening bloods were taken fine. The screening bloods look at levels of hormones in the blood whereas the NIPT and I assume baby blood group test look at the fetal DNA circulating within your blood.

Mas05 · 30/04/2024 23:42

@Hyggeandhugs Can you please update?

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