Understanding Ultrasound Measurements: Weeks & Days of Pregnancy

Question
I had an u/s and the tech wrote I was 17w & 9 days, which doesn't make any sense to me. My doc said it was a fraction of a number but what does that mean. I was suppose to be 17w & 6d. My doc said I was very close to 18 wks. So was I 17w & 6d or 17w & 2d or 17w? I am just lost

Answer
Hi Jen,

Did he write 17.9 weeks?  17.9 weeks is the same as 17 weeks 6 1/2 days.

If you were supposed to be 17 weeks and 6 days, 17.9 days is about as close as you're going to get, especially since 2nd trimester ultrasounds can sometimes be off by up to 7 days.  I think it's a good indication that your dates are good. Try not to let their terminology confuse you - the bottom line is that the ultrasound confirmed the same date that you had.

I hope that helps clear it up!

Sincerely,

Dorothy H, LCCE