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Small sac for gestational age

(5 Posts)
Daniela97 Sun 12-Nov-17 09:19:40

Hi all, I am currently 8 weeks pregnant and went yesterday for a private ultrasound scan (I had a previous missed miscarriage a year ago so wanted this scan for reassurance). The sonography found my little baby and said the baby was measuring perfect at 8 weeks (CRL 16.6 mm) heartbeat was there and looked great, but she noted my sac was small (20.7 mm) . She said she had to go to the back “and look at her charts”. When she came back she said it was within normal limits. That made me happy, but of course when I went home I started to google what a small sac meant. Everything I read said if the difference between the gestational sac and length of baby is less than 5mm, there’s an 80% chance of miscarriage. My measurement difference is 4.1 mm so I have no idea how she put me within the “normal” range.
I just feel lost and scared that something may be wrong and that a potential problem is being overlooked. Then again, maybe I’m just driving myself crazy on google and I just just trust her words.
Any advice or has anyone been in a similar position?

CrmbleBee Sun 12-Nov-17 09:32:58

I had an 8 week scan yesterday too! I don't know about sac measurements- as far as I'm aware our scanner didn't even measure ours. It's possibly worth noting that the measurements aren't totally accurate- she measured the baby 3 times and took an average and the largest measurement was 2mm longer than the shortest. With a difference of only .9mm between that measured and normal I reckon odds are it's actually fine. Also sac length compared to baby length varies depending on angle of viewing (I checked with our pics to see that). Hope this helps!

2cats2goldfish Sun 12-Nov-17 09:43:29

I was found to have a small sac at 9 weeks, and was worrying of course but by about 10-12 weeks the placenta takes over and it is even necessary any more. The nurse at my 12 week scan wasn't even phased and I'm now at 20 weeks. Xx

CrmbleBee Sun 12-Nov-17 09:50:29

2cats2goldfish- are you talking about the gestational sac or the yolk sac?

Daniela97 Sun 12-Nov-17 10:32:47

CrmbleBee- thanks, maybe the measurements are a bit off (we are talking about 9/10 of a mm I guess lol) and I didn’t think about the angle. That gives me hope.

2cats2goldfish- I was wondering if when the placenta kicks in it may help my small sac grow- I couldn’t really find a clear answer about this online though. Your story makes me feel better!

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