I had a scan in the first trimester which was dead on to my lmp for due date, but I had another scan at 19 weeks and the baby measured 18 and 2 days, my doctor did not change my due date he just said she may go over.
This happened to me as well, but I always stuck with the original due date since it was done in the first trimester. Once in the 2nd and 3rd trimester, it will always fluctuate a little by a week or two. So I would say go by the first due date as well.
I agree. Go by the first due date. As said, later ultrasounds are not as accurate as early ultrasounds and can measure off.
thanks thats what i thought also , and another i was just thought about . when i was pregnant with my first boy i didnt understand what lmp was , i thought it was the day your last period ended . so i gave the doctor the wrong date i was off by about a week . so i had my ultrasound at what i thought was 18 weeks but really i was 19 weeks and they never said the baby was measuring big/small . so i guess that just shows babys can range in size ?
You should go with the original due date. 2nd and 3rd trimester ultrasounds can be off by 1 or 2 weeks either way. If your doctor has changed your due date you should speak with him and ask him why. The 1st trimester ultrasounds are the most accurate for dating. Once you get into the 2nd and 3rd trimesters the measurements are based against "average" babies of that age and since babies begin to grow at different rates in the 2nd trimester it's not unusual for the dates to be off. I'm curious as to why your doctor would refer to a new due date just based on the ultrasound being off by 1 week.
Go by the ultrasound date, you don't always ovulate when you think you do which would have put your date back