Hi all. I am 8+2 wks pregnant after a previous loss last year at 7 wks. Also after many cycles of fertility treatment. It's an IVF pregnancy so we have precise dates. Struggling with anxiety throughout. Been the longest few weeks of my life so far!
We had a scan at 7+1 where measuring 7.5mm. Scan dated this at 6+5. Heartbeat seen.
I had a little brown spotting so the clinic offered us another scan 6 days later at 8 weeks where measuring 12.2mm. Scan dated this at 7+3. Heartbeat stronger.
The clinic said not to worry but I am worried about the growth being slow. I wish I could not worry but that is impossible!
Do you think the measurements from the scans sound OK? What experiences have others had with this?
Clinic have offered me another scan next week at 9 weeks+1 as well.
Thanks for any advice.
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LittleL3
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I’m sorry you’re going through this. It must feel like everything is resting on this having got this far.
I got into a panic following my 7 week scan too when the foetus was measuring four or so days behind. Mine then measured a day ahead at the 9 week scan and all seems good so far having made it to 17 weeks. Sharing here the things I found reassuring during the wait between scans
- sonographers are measuring tiny mm and apparently it’s normal to be out by a few mm in these early weeks
- if the clinic says don’t worry then they usually mean it! It would be negligent to not let you know if something was an issue
- I searched online and it looks like reference ranges for what so “normal” at each week do vary by country. In the study below you can look up the CRL and see what age it refers to, the ages in that chart refer to healthy pregnancies, noting there is a range. It looks like 12mm can refer to an 8 week pregnancy in the 95th percentile, which although at an end, is still considered within the normal range: bmus.org/static/uploads/res...
Lots of luck and try to stay hopeful! You’re still pregnant until proven otherwise.
Thanks for your thoughtful response. The chart is useful. Interestingly I have also found that CRL seems to be based on a 1975 study by Robinson and Flemming. I was quite shocked how old this study is! However, there are some more modern studies that suggest that using the CRL from Robinson and Flemming results in underestimating gestational age by around 4 days at 6-8 weeks. One of the more modern studies by McGregor says at 8 weeks you would expect 12mm so that would be correct for me: glowm.com/section-view/head.... I also found a study from 2010 that used a large sample and found similarly about Robinson and Flemming underestimation during this period. However, despite all this I'm still somewhat worried about the rate of growth, but your point about the inaccuracy of measurements at this stage is valid so I will try to be positive! My partner was convinced the way they measure allows a huge error margin as well.
I think I found similar too when I went on international forums and women in Aus were being quoted a different (younger) gestational age for the same size CRL that I had - clearly there is variation in studies!
It’s such a hard period - remaining hopeful whilst knowing your results aren’t totally normal or perfect when that’s the reassurance you want.
I also read a theory that some embryos (even following a precise transfer date) can take a bit longer to implant, which could shift things by a day or so.
Great that you are getting a scan next week. I hear unfortunate tales of women who are pregnant naturally and not under the care of a clinic so only get bad news at the 12 week scan. I hope that at least in our cases the close monitoring gives the answers a bit sooner. Fingers crossed x
I got myself really hung up on measurements but the reality is no human is the same size / weight - as long as you fall into the parameters set everything should hopefully be fine. I’ve gone from measuring ahead at my 12 wk scan to being slightly behind (I am having growth scans at the moment due to IVF / low Papp-a)
I was also told it’s so hard to measure 100% accurately too even when measuring CRL or HC / AC x Please try not to worry x
Thanks for sharing your experience. Yes I think rationally I know I should not worry as there are lots of inaccuracies but it would be nice if was measuring bang-on or ahead not behind! Best wishes for a healthy pregnancy for you.
Hi, I had this in my pregnancy that I unfortunately lost a month ago, the fetus was always measuring 8 days behind and at a 9 week private scan there was no heartbeat and stopped at 7 weeks 3 days, I'm sorry this is so glum and not what you want to hear but when I asked my fertility doctor she said it could go either way so please don't give up! Just because it happens for some people it doesn't mean it happens to all, sorry its not a positive note but I wrote a similar post like this and appreciated all comments positive and negative, good luck! X
When it’s that tiny there’s a big margin for error in measurements and I’m sure a different or even the same sonographer would get different measurements if they measured twice. Also they gave you only a few days “behind” which is literally mm.
I’m only 12 weeks so all these feelings you are having are very raw for me and I can totally empathise.
It’s really good that your clinic don’t seem worried and are offering you another scan. X
I had this in my previous miscarriage where I transferred euploids and one implanted . In my first scan heartbeat was strong but measured one week behind and my clinic asked me to come back in a week , it was same heart beat was strong and measured a week late . Clinic graduated me at 7w4d and I had my next scan at 10 w in a hospital where I learned baby stopped at 7w4d basically same day I graduated . It was really heartbreaking loss because unlike my previous losses I expected things not to go wrong when transferring euploids . I wish my clinic could have monitored me little more before graduating basically 2 -3 weeks I was unattended not knowing I lost the pregnancy . if u are few days behind here and there shouldn’t be a problem but solid week behind in a ivf pregnancy may be something wrong like mine wish they told me this . Good you are being offered another scan in a week , would suggest to get a weekly scan if possible to relive ur stress . Take care hope things go well for you .
Just to update that I had a scan at 9 wks+1 day today. It was measuring 19.1mm which equates to 8 wks +3 days (so still small-ish) and a good heartbeat. Could see a lot of development this time including placenta starting to form so that's encouraging. Hopefully can hold off until 12 weeks for a next scan now. I guess another reason dating might be inaccurate is that implantation can vary by 4 days or so, so perhaps mine implanted late rather than early. Who knows? So many factors. But thanks all for your replies.
Congratulations! Like you I had a small ish bean but it caught up to 2 days behind yesterday at 7 weeks 6 days, so we hang in there for more waiting till the next scans. Good luck.
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