Yes, During an ultra sound they measure the length of the baby, the limbs if visible, head circumference etc.. then calculate an expected delivery date. An ultrasound is accurate to within a couple of days if done at 8 weeks. At 20 weeks it is accurate to within a week. After this babies grow at such diffeerent rates that it becomes increasingly less accurate.
The ultrasound dating has excellent and precise estimation of gestation especially if done in the first trimester (first 12 weeks). After 12 weeks, its accuracy goes down. However, compared to dating according to menstrual cycle, the ultrasound would be more accurate.
If the ultrasound is done in the first weeks of pregnancy it is possible to date the embryo within a few days, an ultra sound done later is not as accurate for dating purposes.
With a dating ultrasound done in early pregnancy, about 5 to 6 weeks.
They claim to be completely accurate but actually can be one week off either way
My wife told her doctor she didn't know when her last mp was, so he sent her for an ultrasound! She lied, we just wanted 2 get an early ultrasound, and it was exact 2 the day and that was at 5 weeks 4 days! Our 1st baby measured within 5 days thru the entire pregnancy, and that was as early as 8 weeks and as late as 26!
Yes. You should tell your Dr so that they can preform an ultrasound to provide you with more accurate dating.
Aftere having had two healthy babies and one miscarriage, I have found ulrasounds to be extremely accurate in dating a pregnancy. My OB is now only performing the initial ultrasound at 8 weeks due to the fact that so many pregnancies end in spontaneous miscarriage (20% of all pregnancies). They would not have patients wait until 8 weeks if they felt the process would inaccurately date the pregnancy. Dating is important in order to make sure that screenings are done at the appropriate times for accurate results (quad screen, glucose test, group b strep swab, etc.). I hope this helps you and good luck!
Biparietal diameter (BPD) is the diameter across the developing baby's skull, from one parietal bone to the other. The measurement is useful in dating the pregnancy and estimating fetal weight after about 13 weeks of pregnancy.
You cannot say that carbon dating is more or less accurate than radiometric dating since it is a form of radiometric dating
It remains a useful technique especially in materials lacking radioactive isotopes. Relative dating by biostratigraphy is the preferred method inpaleontology, and is in some respects more accurate
Not really. Babies grow at pretty precise rates and therefore conception is pretty easy to answer at this early in your pregnancy. You are more likely to have your dates mixed up or that you conceived at a different time than you thought. Yes the date could be off a bit but ultrasound dates are usually pretty clear and accurate on dating embryos. Its all down to the measurements taken of the embryo and last period etc, that give a estimate of the conception date. When an ultrasound shows you are 7 weeks pregnant it actually means you are 5 weeks from conception. Pregnancy is on average 40 weeks from the start of the last period. This is because in the days before ultrasound this was the only date we knew. You don't actually conceive until 2 weeks after this date.
Because an ultrasound at 7 weeks and one at 18 weeks use different methods for estimating gestational age, they have different levels of accuracy. In general, a skilled sonographer's 7 week ultrasound is more accurate for dating than a skilled sonographer's 18 week ultrasound. Talk with your health care provider for information specific to your situation.
No, it is a method of dating materials that is very accurate.
It is not always accurate.
Carbon dating and radioactive dating are more effective, assuming those arn't the same thing. =]
Radiocarbon dating is incredibly accurate. However, on occasions it may not be particularly precise and the date given my include a range of several decades.
Pregnant in Heels - 2011 The Pregnancy Dating Dilemma 2-8 was released on:USA: 3 July 2012Pregnant in Heels - 2011 The Pregnancy Dating Dilemma - 2.8 was released on:USA: 3 July 2012
No, radioactive dating does not produce exact results. No form of radioactive dating produces exact results. But results can be gotten that are surprisingly accurate. As a "for instance" we might look at uranium-lead dating. This dating method can deliver results accurate to a million or two years in a billion years. That's about 0.1 to 0.2 % or so.
Carbon dating techniques
not accurate thanks for asking
When you have a dating ultrasound you are given an EDD (estimated date of delivery) If you count back 40 weeks from this date it should be about when your last period was. If you do not have a regular cycle they may not correlate exactly. 38weeks back from your EDD is approximately when you conceived.
The ultrasound doesnt give you the date. It is estimated by the days you give to the doctors to help, narrow down the date. The first day of your last period and how long you've missed help them in determining your conception date. The picture shows them an image of a fetus and they use that picture to say at what developmental stage the baby is in. Anything is possible.AnswerContrary to the opinion above, the ultaasound does give you an approximate date of conception. By comparing the results of millions of ultrasounds physicians can calculate the age of the fetus based on head diameter, bone length, and other measurements on the fetus. They are usually accurate to within two weeks of when you are due to deliver. Since some women have irregular periods, it is not always possible to calculate the date based on the first day of the last period. Trust the ultrasound! ANSWERI just wanted to add to the above answer. A patient's Last mentrual period is accurate if the patient has a regular mestrual cycle, but this is not the case for many women. Therefore, it is not the most accurate source for fetal age. Ultrasound is the most accurate dating tool for fetal age. The measurement of the embryo (crown rump length) up to 12 weeks gestation is the most accurate. The rate of growth of a fetus will be based on that early measurement for the remainder of the pregnancy. It allows physicians to monitor the growth of the fetus which in turn gives them an estimated due date as well as help them diagnose growth abnormalities such as IUGR (Intrauteriune growth restriction).