Definite LMP & Ov dates, measuring small at Viability Scan

[Raeside]

Hi there - just looking for some experiences of early scan measurements.

According to my definite LMP and very confident Ov dates today I'm 7+4. Went for a Viability Scan yesterday and they saw right sized gestational sac (22m), yolk sac (6mm) but measured the foetal pole at 3.5-4mm, putting me at more like 5-6 weeks. Dr said he saw a 'fluttering' but not enough to measure with the Doppler so I've to go back next Monday to review.

I'm now convinced my morning sickness symptoms are reading and boobs less sore and that I've a non-viable embryo! Am I going mad?

I think there is more variation in early pregnancy than is often credited. There are plenty of people who's EDDs have been adjusted by weeks, so that their BFP came before conception (according to scan dates), and who have gone on to have uneventful pregnancies and healthy babies.

Don't forget they use average sizes to calculate gestation, and not everyone is average. There has to be some variation in order to calculate an average.

Don't forget that the measurements are made using sound waves. They effectively choose a 'slice' through the abdomen and use the compute to calculate measurements of what is visible.

Please try not to panic/worry now. It could be that your embryo is developing at a different rate to average, or is a different size to average, or that it was not optimally placed to be measured.

In a couple of weeks everything could be fine. Today you are pregnant. A heartbeat was seen. Please try not to worry.

Thanks Indomitable

Bump

I had a scan at what I know was 7+2 (I had ovulation scanning so I knew the dates were right) and baby measured 6 weeks exactly. Googling it seemed that this is really common at early scans and when we went back at 9 weeks she had caught up somewhat in growth and was only 4 days behind my dates.

I am now 32 weeks so she was perfectly viable. She does however have a rare chromosomal anomaly that causes slow growth which could explain the early scans but it seems most babies who measure small at early scans have no issues at al. I hope all goes well for you

Thank you TheDA and good luck with your imminent arrival!

Really hoping for the best for you Reside. As previous posters have said, it's not an exact science, especially so early on. However, it may be that things aren't quite right. I've had it go both ways, and ultimately think it's good to prepare for the worst but hope for the best.

OP early scans are notoriously inaccurate. What they are measuring is incredibly small, so the error margin is high in comparison. Also if bubba is at a slight angle you'll get a short crl reading. They measured me nearly a week behind at 6 weeks and bang on 7 weeks a week later, I just think they got a more accurate measurement. Dating at 12 week scan is much more accurate as baby is bigger. Mine is IVF so I knew exactly when dates were.

Fingers crossed all goes well for you, and congrats.

Thank you Bunty and BWCat