Head Size-Measurements- Huh?!?!

[Mom2Ms]

This is probably the stupidest question that has ever been asked, but even after asking my doctor to explain it, I still don't get it. Im certain that this pregnancy has made me stupider because my comprehension skills at this point have taken a vacation. 

I had a growth scan today. They said the head circumference is measuring at 60%. Ok. I can work with that. But then they said that the other measurement, the width is measuring at 90%. Um. WTF. Am I having a ET? I picture ET coming out of my ute. The rest of him is measuring at 64%. Someone who is clearly much more intelligent than me,  please explain this to me because all I can picture is ET. I know its simple, I know it is, but Im just not grasping it. 

[Mom2Ms]

That's somewhat helpful... I'm just having a hard time wrapping my brain around it. I thought width was part of overall circumference, which makes it confusing, considering they are like a 30% dufference!

[seamonster]

Maybe they're talking about percentiles? Ideally length, weight, and head circumference should be close together percentile-wise. Maybe width wasn't referring to his head? Or a particular dimension of the head? I don't know since my doctor never referred to the actual numbers on my growth scan, except to tell me his estimated weight or length and never said percentages. I would normally tell you to ask your doctor about it, but you already did. I would say if they aren't worried, don't be worried. I doubt you've got ET in your uterus.

[aggiebug]

Feb 21, 2015 3:25:25 GMT -5 Mom2Ms said:

That's somewhat helpful... I'm just having a hard time wrapping my brain around it. I thought width was part of overall circumference, which makes it confusing, considering they are like a 30% dufference!

I would say a large part of it is the inaccuracies of the measurements on ultrasound. At this point the 60% and 90% is maybe a half a cm or something fairly small so it would be easy to get such drastic differences in percentiles.