Ultrasound: Sonogram - American Pregnancy Association

Are Ultrasounds Accurate for Predicting Due Dates?

how accurate are ultrasound dating scans

Ahh, I see your problem. They dated me at 12 weeks Moving from a cot to a bed Video: We usually get better images during transabdominal ultrasound if the bladder is partially filled, so to help your examination we ask you to drink water prior to the assessment.

Find Out How Well a Sonogram Can Tell You Your Due Date

Ultrasound scans performed before 12 weeks are pretty accurate but they still have a 5 day plus or minus window for error. Sign up to receive free emails and track your baby's development. Pregnancy dating is most accurate during the first eighteen weeks of pregnancy. Your doctor may be concerned about your pregnancy because of abdominal pain or vaginal bleeding. The baby is growing inside a small sac, called the gestation sac.

What are the best products for you and your baby? From travel systems to sterilisers, you can find out all you need to know from our Mumsnet Best reviews. I've split this question out from an earlier thread I've just been for my 12 week scan and they have told me I am 15 weeks pregnant.

This simply does not work out - I am sure of my dates and even did an ovulation test to check when I could conceive that month. They must base the measurements on averages, but 3 weeks out seems like a lot. Has this happened to anyone else? If so, did your dating scan turn out to be right according to later scans? Or might they tell me later on that my dates were correct after all. Can some babies just grow faster than others? Are you measuring your dates from the first day of your last period?

It's really common not to do this. A scan date is normally spot on although if there's a few days difference between the scan date and your date they will go with your dates. I think mine was spot on, 12 weeks 2 days was actually 11w6d which I agreed with but they are not infallible.

Doesn't really make any difference as my daughter was 3 weeks early. Yes I am measuring it correctly - I was a bit obsessed and recorded everything in my diary.

They said that my last 'period' might have just been spotting but I'm sure it wasn't. Everything ties in with my dates first day of last period, date of ovulation test, date of getting jiggy!

I am simply baffled that the scan shows the baby to be 3 weeks bigger than it should be. DH is starting to shoot me suspicious glances!!!! Ahh, I see your problem. You could just have a long baby?? They can make mistakes at a 12 week scan as the baby wriggles about alot. I'm in a similar position.. I was scanned at what I thought was 8 weeks 4 days..

I was sure of this as I had MC'd the previous month unfortunately, done ovulation tests etc and then when they scanned me they said I was 7 weeks 2 days which just makes no sense given when I ovulated and I'm constantly worried about it now. I just hope baby is developing okay. MW said it was fine and you never know how the body works ovulation wise though.

Harder to see how you could be more pg than possible from jiggy days - are you sure ther weren't any drunken ones you've forgotten about. Early scans can be out by 5 days or so but I thought by 12 weeks they were regarded as fairly accurate. I don't think they would be that far out. Perhaps you ovulated twice that month? I was sent to EPU as was being very sick. By my dates I was 7 weeks, by theirs I was 6 weeks. The sonographers explained that the earlier the scan the more accurate as the embryo has very standard development.

I had one embryo with fetal pole and heartbeat and one blighted ovum. Pregnancy dating is most accurate during the first eighteen weeks of pregnancy. Measurement of the sac at five to seven weeks is not accurate. Measuring the crown-rump length gives an accuracy of plus or minus three days at seven weeks; this test can be used from the seventh to the fourteenth week.

Between fourteen and twenty-six weeks, measurements of the biparietal diameter, the femur length and abdominal circumference are generally used. The accuracy is plus or minus seven to ten days. The accuracy further declines with advancing gestation age.

All it means is that your baby is measuring big or small. It does not necessarily mean you ovulated on a different day than you think you did. Unless you are off by 2 weeks or more, then your dates are probably accurate. I go for a dating scan on May 28 I should be a little over 8 weeks then.

It could have been implantation bleeding rather than the period you really thought. Generally ultrasound dating is pretty accurate Find Email Marketing Software. Related Questions Are the dating scans accurate? In the uk week dating scan, how accurate? How accurate are dating scans? Answer Questions Sex pill and Condom? Is it normal for clear liquid to come out breast currently 19 weeks 4days? I know you aren't supposed to shave pubic hair.

Iamges: how accurate are ultrasound dating scans

how accurate are ultrasound dating scans

Click here for additional information. Of all of these uses, dating the pregnancy is the most common reason to use ultrasound, particularly when the expectant mother cannot remember the date of her last period as in breast-feeding or irregular cycles. You will have a large towel covering your lower body, in addition to wearing a gown during the transvaginal ultrasound.

how accurate are ultrasound dating scans

An ultrasound in the first trimester can give an accurate estimated date of confinement EDC to within days.

how accurate are ultrasound dating scans

Home Pregnancy Health How accurate are ultrasound dating scans scans. At weeks ultrawound, your baby continues to change appearance as it grows and develops. But early ultrasound due dates have a margin of error of roughly 1. Early scans can be out by 5 days or so but I thought by 12 weeks they were regarded as fairly accurate. The sonographer explained that indicated that this was a twin pregnancy with only one twin viable and could explain the search for dating partner confusion as I may have ovulated twice in one cycle. Ectopic pregnancy and miscarriage: My scans keep giving me different due dates.