gestational sac smaller then fetus

i was just wondering is it normal for the gestational sac to measure smaller then the fetus? My friend had her u/s yesterday and the fetus measured at 8 wks 4 days with a nice strong heart beat but she noticed on the pics they gave her the gestational sac only measured 6 wks 2days. the dr said everything is fine and didn't even mention that i guess it is normal but i thought i would ask you all before i give her my opinion.
thanks

[duehring]

I had the exact same thing happen. They measured a little over a week different. The sac measured small by a week. The baby took up probably 3/4 of the sac from looking at it. The sono tech lady told me that I would probably miscarry because that is not a good sign. I was terribly upset and prepared myself to miscarry. I called my doctor and she told me not to worry about it and that it can be off by up to a couple weeks. She was right because I carried a healthy baby to term.

From my research I did at the time it looks like it is definitely a bad sign and that even with a strong heartbeat if the sac measures to small it can make the baby stop growing. I also think though that because everything is so small at this time that the measurements can be off too.

I would advise her to not research it much on the internet because it will just freak her out and won't realy help anyway. That is what happened to me.

I rented a doppler right away and starting at 9 weeks listened to the heartbeat every day just to make me feel better. Then I got my doctor to give me another ultrasound at 13 weeks because of my stress with it and the sac and baby both measured perfectly then.

[duehring]

Another thing that I was going to say is that it depends on the difference in size between the baby and the sac. If she was given the measurements in mm size then this is what is said in the ob books. The ob tech looked this up for me and gave me this information and I was in the 26% chance of miscarriage category. I believe my difference in measurements was close to 7 mm.

The rate of fetal death was 80.0% when the gestational sac diameter-crown-rump length difference was less than 5 mm, 26.5% when the difference was 5-7.9 mm, and 10.6% when the difference was 8 mm or more (P less than .0001 compared with less than 5 mm)

Like I said though it would be really easy to measure wrong when the baby and sac are so tiny.

[AnnieBrooke]

I would take the doctor's reassurance over the tech's comments any day of the week.

[mary345]

Thankyou for your comments. She said that the tech didn't even mention anything about it no one did they just everything was fine and baby was measuring perfectly for her dates and they gave her a cd or all of her pics and just happened to notice it on the one where they measured the saw. I guess everything is fine considering no one even mentioned it.