Accurate dating sonogram
I checked online and it seems ultrasounds are pretty accurate for dating for the first trimester...anyone else have similar results and a change of dates?
Hi, I think with the very early scans, 5-6 weeks they can be a little bit off.
In our practice, the EDC will be determined at the first prenatal visit whenever possible, and subsequent ultrasounds, which often will report a different (often earlier) EDC will not override the first EDC.
In fact, the only time that this doesn't apply is when the date of conception is known without doubt, as when an infertility patient conceives with timed intercourse or artificial insemination.
The accurate determination of a patient's "due" date, referred to by doctors and midwives as the EDC (Estimated Date of Confinement) or EDD (Estimated Date of Delivery), is very important for a variety of reasons.
Announcing: Experts in mesh and bladder sling revisions and removals. Call us for your next appointment for customized bioidentical hormone pellets!Typically they will change if it’s off by 6 days, the maternal fetal centre I went to says that dating is much better between 10-13 weeks and after that time babies all grow at different rates.I’ve had one dating scan and it was at 12w 5d and I was measuring 13w 1d so right on time with my lmp.my doc said scans done at 8-9 weeks are more accurate in determining dates then as baby gets bigger because of the way baby is lying.However in your expierence since baby is measuring bigger and u see so much more at 10 weeks instead of 8 i would go with ur 10 weeks.Other information used to calculate the gestational age, or the number of weeks and days from the first day of the last menstrual period (LMP), includes the size of the uterus on pelvic bimanual examination.However, it is extremely common to encounter patients who have irregular or infrequent menstrual cycles, or have fibroid tumors that cause their uterus to feel enlarged on pelvic exam, or who conceive shortly after a pregnancy ends (without ever actually having had a period after the last pregnancy), or who got pregnant while taking birth control pills, and these situations often render the above methods useless and misleading when trying to figure out a reliable EDC.The most common misconception we encounter almost daily, has to do with how accurate ultrasounds are in fixing the EDC at different stages of pregnancy.Many patients believe that the later in pregnancy an ultrasound is performed, the more reliable the EDC calculated by the ultrasound is.The later in pregnancy, the more inaccurate it is to date a pregnancy.Roughly, if an ultrasound differs by a week in the first trimester, dates are changed.