Ask Experts Questions for FREE Help !
Ask
    babymommysa's Avatar
    babymommysa Posts: 1, Reputation: 1
    New Member
     
    #1

    Nov 17, 2014, 01:49 AM
    Ultrasound reliability on determining conception date
    Hi.


    I did an ultrasound at 3 Oct and it said I was 5w5d pregnant. My LMP was on 28 Aug. I am an average cycle of 26 days. With my longest cycle being 28 days. Is it possible to determine the conception date from the ultrasound? And how accurate will it be? Can anyone tell my what my possible conception date was?
    J_9's Avatar
    J_9 Posts: 40,298, Reputation: 5646
    Expert
     
    #2

    Nov 17, 2014, 01:56 AM
    Gestational dating is an inexact science based on mathematical formulas. Since you don't know exactly when you ovulated, it is a guessing game based on that formula. Gestational dating has a two week + or -. Therefore, if paternity is in question, you will have to have a DNA test after baby is born.
    Fr_Chuck's Avatar
    Fr_Chuck Posts: 81,301, Reputation: 7692
    Expert
     
    #3

    Nov 17, 2014, 06:27 AM
    Yes, give or take two weeks is about correct with the dating.

    The dating from ultrasound is based on average sizes, so many babies larger, many smaller, some right on average.

    The idea of an "exact" day is just not possible. Is there a reason for concern?
    J_9's Avatar
    J_9 Posts: 40,298, Reputation: 5646
    Expert
     
    #4

    Nov 17, 2014, 06:48 AM
    Dating on an ultrasound is done by development of specific organs and length of certain bones such as the femur. Fetal organs develop at different times during pregnancy. The firs organ that develops is the heart, and so on. Dating by ultrasound is determined by the development of the fetus. Not by size of the fetus alone.

Not your question? Ask your question View similar questions

 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

My due date is Dec 3 and based on that my conception date is March 12. [ 3 Answers ]

My due date is Dec 3 and based on that my conception date is March 12. I had sex on Feb 26 and again on March 12. I need to know which of these dates could be the correct date I got pregnant. I am confused because I had my LMP on March 7 to March 11 which was a light(spotting)period which I am use...

Determining conception date. [ 2 Answers ]

My son was born on 10/26/10 I want to know when he was conceive

Determining conception date [ 2 Answers ]

I want to know the exact day the I came out pregnant my last period was October 16,2010

How accurate is a ultrasound at 32 weeks for the conception date? [ 5 Answers ]

How accurate is a ultrasound for the conception date if they tell me that I'm at least 32 weeks pregnant. When I count back the weeks something doesn't add up because I wasn't with anyone during that time. Just 3 weeks before and a week and a half after.

Ultrasound and conception [ 1 Answers ]

When you go for an ultrasound and they tell you e.g. 18 weeks and 1 day... do you count back from that day 18 weeks and one day? Is the date given here your conception date or do you have to take off two weeks I am getting confused with all this


View more questions Search