Only gestational sac on ultrasound???

My ultrasound at 6 weeks and 4 days showed a baby and heartbeat. You may have implanted later, 10 or 11 days, instead of 6 or 7 days, which could account for a few days. I'm sure everything is fine.

When you have a very early OB ultrasound, before we can see a fetal pole, the estimated gestational age is determined by the sac size. If your sac measured 5.5 weeks, then it would be too early to see a fetal pole. A 11mm size sac does correspond to about a 5.5 week sac. Did you see a yolk sac? That can be seen in the 5th week, but the fetal pole is not seen until week 6. If the sac was within the endometrium (or center of the uterus) and it was round, it really does sound as if you are just a tad bit too early to see the baby. You have received no ominous signs.

On a side note, this is why I really dislike early OB ultrasounds, unless we are concerned about an ectopic pregnancy. Most of the time, we are just too early to see a baby, and the mother must go another week before rescanning. That week is complete torture and very stressful. The majority of the time, a week later, the mother finds out that there was never anything to worry about. It is against human nature, since we are worriers, but if you can, try to relax. Stressing out does nothing good for you or your baby's health. Best wishes....

"The gestational sac is the earliest sonographic finding in pregnancy.....The gestational sac first appears at about 4 weeks gestational age.....The yolk sac first appears during the fifth week of pregnancy....A mass of fetal cells, separate from the yolk sac, first becomes apparent on transvaginal ultrasound just after the 6th week of gestation."

http://www.obgyn.ufl.edu/obgyn101/Ultrasound/1st_t...

Hi, thats a good question. I am going to check it out with yahoo search engine. If I get some results i will post here.