Q&A: My ultrasound measurements say my baby is two weeks behind our calculated date.
I am 19 weeks, 3 days pregnant right now... depending who you ask.
I know for certain the date of my LMP was 5/7/01. No doubts. Cycles were running around 32 days since January when I stopped taking the pill.
I had my first ultrasound early Sept. at which point we thought I would be a few days shy of 18 weeks. The ultrasound tech came back with measurements that I was likely only 16 weeks and some days.
My question is: What is the accuracy of dating by ultrasound at that stage?
Also, we heard the heartbeat at my "11 week" appt. If the ultrasound dates are correct, we actually heard it at 8.5 weeks.
Lastly, if the ultrasound dates are off - what else would cause my baby to measure a week or two off? Could there be something wrong?
If your baby CONSISTENTLY measures a week or two off, then more than likely your dates are wrong and everything’s OK. The only way you can be sure of the date is to be certain of the conception date, e.g., your husband came into town for one night and then went out of town–situations like that.
If your baby is a couple of weeks behind, and that measurement falls further behind, then you may have growth restriction problems. But that shouldn’t be if your baby is always the same amount behind–that’s just a skewing of the growth curve because of an initial error in calculating conception.