Ultrasound accuracy

[lisa386]

I am wondering on a vaginal ultrasound at 4 weeks would a gestational sac appear. WOuld you say in the first 6 weeks that calculating conception date is accurate. I read that at 4 weeks yuo can onl see the thickening of the lining and at the end of 4 weeks to 5 weeks can you see the ges sac...anyone know for sure?

[connorethansmom]

I can tell you what happend with my son.  At 5.5 weeks I we could see a yolk sac and at 6 weeks still the same.  By 7 weeks we saw a baby with a heartbeat.  Good luck.

[michelle148]

The gestational sac first appears at about 4 weeks gestational age, and grows at a rate of about 1 mm a day through the 9th week of pregnancy.

Your ability to identify an early gestational sac will depend on many factors, including the capabilities of the ultrasound equipment, your approach (vaginal or abdominal), your experience, the orientation of the uterus (generally it is easier to see if the uterus is anteflexed or retroflexed) While a gestational sac is sometimes seen as early as during the 4th week of gestation, it may not be seen until the end of the 5th week, when the serum HCG levels have risen to 1000-1500 mIU.

Gestational sac size may be determined by measuring the largest diameter, or the mean of three diameters. These differences rarely effect gestational age dating by more than a day or two.

[krushing]

It does vary with each person.  I had my first scan with my last pregnancy at 6W1D and saw the baby and heart fluttering.  And at that time my HCG was 1600 and something.