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Date of last update: 10/14/2017.

Forum Name: Gynecology

Question: How pregnant am i?

 Pen86 - Thu Oct 27, 2005 7:47 pm

I am unsure if this is the right forum, but anyway....I am meant to be 13 weeks pregnant today, i had an ultra sound last Monday when i was 12w3d. It showed the babies length to be 8cm?! Is it true that this is the size for a baby that is about 14 weeks? I am quite confused. Any help would be great.
 Michele P, RN - Thu Oct 27, 2005 10:50 pm

Moved this post to different forum...

According to ultrasound guidelines, at 13weeks you should measure approx. 7.5 cm which is 3in. So you are pretty much within normal limits. You did not include the weight that they are saying the baby is at but at 13 weeks, the weight is approx 40gms which is 1.4 oz.

There are different ways that your duedate is determined - by ultrasound date & by last period date mainly. They start with the date of the 1st day of your last normal menstrual period, add 7 days, subtract 3 months, add 1 year. This will give you your due date. This is the date that is punched automatically into the computer of the unltrasound machine & called your "Menstrual age".

The other due date is by sizing. This will be pretty close to accurate, more so then dates because for 1 thing, conception may not occur on the day of intercourse, it can even happen several days after.

Normally, as the baby grows, due dates change on the ultrasound. Again, this is due to sizing. Some mothers carry smaller or larger....duedates are pretty much a guessing game as to EXACT date but they are normally pretty close.

Best of luck :)

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