transvaginal ultrasound dating

[denise7]

is trans vaginal ultrasound in first trimester (8 weeks from lmp, for example) dated from conception or lmp?

[feather2e]

it is from conception minus two weeks so if conception is 6weeks they say you are 8 weeks .

[neasyc]

i think its lmp

[BessL]

It's kind of both -- the date you are given is from when the LMP would have been if you had a normal 28 day cycle.  For instance, I have a long and irregular cycle -- it varies from 5 to 8 weeks.  Ovulation occurs 2 weeks before your period, regardless of how long your cycle is, and that is the part of the menstrual cycle which does not vary -- the time before ovulation varies widely.  This means that if you have a long cycle, you cannot rely on dating from you LMP because your dates will be off.  If you have an ultrasound say 5 weeks after conception, you will be told you are 7 weeks pregnant, from you LMP because they assume a 28 day cycle, when in reality your last period could have been weeks earlier than that.  I hope I'm explaining this clearly.  Go ahead and ask me how I know this  :-)

[cindy82]

always remeber that its a estimate only. they can only guess about how far along u are, thats why they say it can come 2 weeks befor or after your due date

heres more info
http://www.stages-in-pregnancy.com/pregnancy-due-dates.html

[Shannon125]

Alaysha and lou are correct. In general in the United States, pregnancies are always dated from LMP. Some doctor's may use conception date but that is not accurate whereas LMP is definitely accurate, you know when your last period was. Also, I believe that in Canada and some other countries they may use conception date but I am not 100% sure on that one.

[lou7511]

It is definitley from your LMP, I have has two done and they were dated from LMP.  This is how pregnancy is always dated;so if sonographer said you were 8 week, you had your last period about 8 week ago and concieved around 6 weeks ago.

[Crysi]

It is always dated from conception. How old the baby looks.
From LMP doesn't make sense to do because you already know when your Last Menstrual Period was, you would always know the age if it was done by that.

[alaysha]

Any ultrasound no matter if it is vaginally or on the stomach is dated from the LMP. Some doctor will date it from conception but that very rarely happens.

[Linzola1]

I believe ( but not 100% sure) that it is from conception. Sorry I could not be of more help.