Gender on blood test different than ultrasound??

a&abestic

We had a blood test done at 10 weeks and it said girl.  Just had my 19 wk anatomy ultrasound and the tech said boy..?? I'm now shocked and confused.  I was completely prepared for a girl and the dr said the test was probably just wrong..?  Has this happened to anyone?  Any chance they were just seeing the cord?  Legs were crossed and covered the bum the whole time and baby wouldn't move them .. not sure if that makes a difference or not ..
thanks!

pettycrocker

Oh which test was it? There is a small margin for error either way (blood test and ultrasound) 

knottie8155f9cdb10dbe5c

I'd take the blood test over ultrasound, the blood test is a genetic screening so tends to be acurate. The ultrasound your trusting the eye of a tech. And if the baby wasn't all that cooperative i'd be hard to say.

momlyfe29

This exact thing happened to me. My blood test ( testing for genetics and disabilities) said girl and my 18 week ultrasound said boy. I now have a healthy 1 year old boy

eggplantface

From what I understand about the blood test and how it determines sex, they look for evidence of a Y chromosome in your blood. If there is none, then they will say it's a girl, but that's not 100% because it could just be that there weren't enough Y chromosomes to detect. If they see a Y, then they know it's a boy because, as a woman, you don't have any Y chromosomes. So it is possible that they didn't see any Ys and therefore said girl, but there just weren't enough Ys to detect it at the time of the test and it is, in fact, a boy.

[Deleted User]

eggplantface said:

From what I understand about the blood test and how it determines sex, they look for evidence of a Y chromosome in your blood. If there is none, then they will say it's a girl, but that's not 100% because it could just be that there weren't enough Y chromosomes to detect. If they see a Y, then they know it's a boy because, as a woman, you don't have any Y chromosomes. So it is possible that they didn't see any Ys and therefore said girl, but there just weren't enough Ys to detect it at the time of the test and it is, in fact, a boy.

This.  I would go with the ultrasound.  Go to a different place for a second opinion ultrasound if you want - but those early tests have a margin of error ESPECIALLY when they tell you it's a girl for the above reason.

livingthedream-3

eggplantface said:

From what I understand about the blood test and how it determines sex, they look for evidence of a Y chromosome in your blood. If there is none, then they will say it's a girl, but that's not 100% because it could just be that there weren't enough Y chromosomes to detect. If they see a Y, then they know it's a boy because, as a woman, you don't have any Y chromosomes. So it is possible that they didn't see any Ys and therefore said girl, but there just weren't enough Ys to detect it at the time of the test and it is, in fact, a boy.

This is what I was told. As small of an error as it is, there is a higher chance of error with saying it's a girl because you can just not have picked up enough to recognize the Y chromosome yet if there is a Y chromosome there is a Y chromosome.