I just don't know.?

By my period I'm 35 wks but my ultra sound says I'm 38 wks. What should I go by? I guess the ultra sound goes by the size of the baby. So does that mean if I go full term to 40 wks I'll have a 3 wk (size wise) baby? She already almost 7 lbs! I'm scared!


I knew exactly when I got my period, so I know that's right. The baby had been big for it 's "age" the whole time.

Update 2:

I'm sure everything is ok. I guess I'm just wondering if the dr. will let me go 40 wks or will she go by the ultra sound. Meaning I would have the baby in the next 2 wks instead of 5.

7 Answers

  • 1 decade ago
    Favorite Answer

    Go by your period date, not u/s date. As the others said, late term ultra sounds are very innacurate for measuring. I measured 3 weeks ahead from week 32 on.

    My doctor told me that they were usually plus or minus a pound, usually minus. They were under by a pound with my oldest, but it was the exception, not the rule.

    Your doctor should let you go to 40 weeks and not induce early. The longer you are pregnant, the better it is for the baby. Pre term inductions shouldn't be done unless there is a medical need like pre eclampsia.

  • 1 decade ago

    Dont worry ... you and the baby are just fine. Your period might be right and you might be having healthy big who is big for his age and that is okay as long as he is healthy. When he is born, he will still be a newborn just like other new borns.

    My friend had a 8 lb baby at 35 weeks and they always told her she was ahead. The baby is such a cutie pie and is completely normal and acts according to his age.

    Unless the doctor tells that there is something to worry about, you are fine.

    Just relax and enjoy your pregnancy.. you are going to have a beautiful baby.

  • 1 decade ago

    If your Dr. thinks the baby is going to be too big, he/she may induce at 38 weeks. Thats when a baby is considered full term. No Dr. anymore will induce before then because of possible problems.

  • Anonymous
    1 decade ago

    Ultrasound accuracy in late pregnancy for determining the size of the baby is about 0% accurate

    In diabetic pregnancies it has been demonstrated that ultrasound measurements are not more accurate than clinical examination to identify high birth weight babies.(4) This led to the memorable title of an editorial of British Journal of Obstetrics and Gynecology: "Guess the weight of the baby."


  • How do you think about the answers? You can sign in to vote the answer.
  • 1 decade ago

    periods can be tricky b/c sometimes you will get one or two even if you ARE preggo. Ultrasounds are pretty accurate; but beleive me, your doc WONT let you deliver a baby your body can't handle. If the baby gets TOO big, he may want to induce or c-section earlier than the EDD to be safe (for BOTH of you.) Talk to him & tell him your worries...Good luck!!!

  • 1 decade ago

    the ultrasounds later in pg are not as accurte as the ones that are done in the begining. I have had friends that were told they were going to have a 10lb and it was only 6 or 7. Don;t worry you will be fine.

  • 1 decade ago

    just come down!!!

    the more you stress the sooner the baby wants to come out.

    go over your date's again and GOOD LUCK !!!

Still have questions? Get your answers by asking now.