Measuring behind at 7-week IVF scan with strong heartbeat

Vjw26 · 2026-10-01T17:44:07+00:00

IVF - I had my first scan yesterday at 7 weeks + 1 day. Baby was measuring behind at 3.4mm, whereas they expected baby to be around 10mm at this stage. The heartbeat was strong and regular, which I’m obviously really grateful for, but I’m honestly spiralling a little with the measurements being so far behind. I’m trying to stay positive, but I’d really love to hear from anyone who has been in a similar situation where you were measuring smaller at the first scan and things caught up at a later scan Thanks

Toddlergrumps · 01/10/2026 20:47

My son measured behind, there was no heartbeat at 6 weeks and he was constantly measuring behind until about 12 weeks. I had about 5 scans between 6 weeks and 12 weeks as he wasn’t developing as expected, he’s 2 now!
I would try not to worry too much, they are so small at that age a slight mis measure and it looks behind, but we are talking mm - it could just be the angle of the scanner.
I also had scans just before I gave birth when they told me he was huge and needed inducing (which I refused), he was 7lb at full term - so I wouldn’t go too much by measurement so long as he’s developing ok.

Miraclemuma03 · Yesterday 11:28

How many days behind does that make it? Iv had 2 scenarios, one ivf pregnancy was measuring 9 days behind and we had mc at what would have been 9 weeks, the heartbeat just stopped one day and we needed a d&c. The very next ivf pregnancy the little one was measuring 5 days behind, i thought we were going to mc again but every week little one kept growing like he was ment too and throughout the entire pregnancy he measured 5 days behind, he was born at 38 weeks weighing 7lb. Sometimes the little embryo implants later or a little slower, so may not have implanted until day 4 or 5 where alot of embryos inplant on day 2 at the earliest , some finish implantimg faster then other, it takes a couple days to fully implant ao depending on all these factors being a little bit behind doesnt mean anything is necessarily wrong but in my experience more then 5 days behind is wear it starts to get merky because it usually means the embryo isnt growing appropriately and too late of an implant can cause issues with long term growth..I hope everything turns out to be ok.

Original poster

Vjw26 · Today 06:21

Miraclemuma03 · Yesterday 11:28

How many days behind does that make it? Iv had 2 scenarios, one ivf pregnancy was measuring 9 days behind and we had mc at what would have been 9 weeks, the heartbeat just stopped one day and we needed a d&c. The very next ivf pregnancy the little one was measuring 5 days behind, i thought we were going to mc again but every week little one kept growing like he was ment too and throughout the entire pregnancy he measured 5 days behind, he was born at 38 weeks weighing 7lb. Sometimes the little embryo implants later or a little slower, so may not have implanted until day 4 or 5 where alot of embryos inplant on day 2 at the earliest , some finish implantimg faster then other, it takes a couple days to fully implant ao depending on all these factors being a little bit behind doesnt mean anything is necessarily wrong but in my experience more then 5 days behind is wear it starts to get merky because it usually means the embryo isnt growing appropriately and too late of an implant can cause issues with long term growth..I hope everything turns out to be ok.

I’m 8 days behind and have zero symptoms I’ll be 8 weeks on Monday.
I did also take a digital pregnancy test which I would have expected to show 3+ weeks pregnant but still only showing 2-3 weeks so I’m preparing for the worst .
thank you

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