discrepancy in dates - early ultrasound

[Cathds]

Hi
According to my dates I am 8weeks pregnant, but had an ultrasound yesterday and measured only 6weeks. It was an abdominal ultrasound and an embryo with a heartbeat was seen. However, I know the date of my LMP (29 Feb) is definitely correct.  I got my first positive pregnancy test four days after my missed  period which I was expecting on 28 March. I am very worried that the baby has stopped growing or there is something seriously wrong as I know that i did not make a mistake with my dates.Is there any way that the pregnancy could be ok and if so what explanation might there be for the two week discrepancy in dates? I am really worried.
Thanks for any help with this.

[lulu0282]

This has happened to me twice.  The first time my dates were off by a little over a week (behind) and I was measuring  6.5 weeks when I thought I was almost 8.  The baby was just fine.  Saw a heartbeat and fetal pole.  My dates were just off....this is normal.  The second time (last month) I went in at the 8 week mark and the baby was only measuring 6 weeks and I thought I was 8...but there was NO heartbeat.  I miscarried that pregnancy :(  So if you heard a heartbeat and your doctor is not worried, then I wouldn't be worried.  Dates can EASILY be off in the beginning.  The heartbeat was a great sign :)  Good luck to you!!

[adgal]

Hi there.

First trimester ultrasound dating is pretty accurate, but sometimes you hear of stories like this.  If there was no heartbeat, I would be concerned.  But, if there was a normal healthy heartbeat, that is a pretty good indicator all is well and the discrepancy could be something as simple as human error (ultrasound tech).  I would have this conversation with your Dr. and perhaps request a follow up ultrasound for peace of mind.  But in all honesty, it does sound like things are ok.  Congrats on your pregnancy and wish you all the best.