Measuring small at first scan

[Commonsense22]

Hello
I can't help but be concerned. I had my first scan at what was meant to be 7+5 and the baby measured 7+1 with heartbeat.
The thing is, I know when ovulation was and 7+1 just doesn't line up even if fertilisation occurred at the end of the window.

My gut is telling me that this isn't looking good. Any similar experiences?

At 7 weeks baby is so small that the tiniest difference in measurements can mean days of difference in dates. I really wouldn't worry about 4 days difference, it may be that by your 12 week scan you dates line up again or they may change your due date. You have a heartbeat, that's a very positive sign!

My dates were the opposite and they tried to bring my due date 8 days forward but it would have been impossible based on ovulation sticks etc. baby arrived on his due date (4 days earlier than based on last period)

Good luck!

That early 4 days isn’t out of the realm. There is error with the measurement due to how small it is and the equipment.

I knew when I ovulated- I used lh and bbt. At 9 weeks at a private scan they put me back 3 days. They said if it’s more than 5 days they would start to be a bit concerned but within that there’s the error in measurements. By the nhs dating scan at 13+3 they put me forward (from the date I had based on when I ovulated) by 2 days. So that’s 6 days difference between two scans that were 4 weeks apart.

My ds is now 1 and healthy.

Thank you both.
I think my gut is still telling me something is not quite right bit hope to be wrong.

I had an early scan today at what my app said was 7w+3 but they measured it at 6w+6. There was a heartbeat and she didn't seem very concerned, she said especially as my cycles are quite long on average she's not worried and the baby is all folded up at this stage so measurements can be difficult to get accurately. I have also have a private scan booked for 9 weeks so I'm trying not to worry until then. Holding on to the fact there was a heartbeat, and I'm starting to feel quite nauseous!

My baby was an ivf baby, so I knew exact dates and yet at my first scan they still changed my due date and said I was 5 days behind. All was fine. Try not to worry, the heartbeat was seen which is a huge milestone.

I really wouldn't worry, it's a good sign there's a heartbeat. The measurements are so tiny at that stage, you'll get a better idea at 12 week scan. And even if you know ovulation date, implantation can happen between 6-12 DPO so it'll never match up exactly.

I went for a scan and was measuring behind at 6 weeks and 3 days. I was told not to worry as there was a heartbeat and measurements can be off so early on. I went back five days and there was no heartbeat and baby was measuring 6 weeks and 4 days.

I really hope this isn't the case for you, but just wanted to share my experience x

I’d say try not to stress! It’s only 4 days difference and as others have mentioned implantation could’ve happened later & they're still so tiny at that point measurements might not be spot on. you have a heartbeat so that’s great!

I had exactly this, went at 7+5 and measured 7+1...by the time I got to my 12 week dating scan, baby was measuring bigger at 2 days ahead of my original dates (so would've been 6 days ahead of their early scan measurements) try not to worry, whilst they are so small even millimetres can make a difference

Thank you

Went for my 13 week scan and was put back by 5 days and not even given it a second thought. If the midwife was concerned she would have said something I really don’t think it matters it’s millimetres

@Commonsense22 as others have said, any slight error in measurements in those early days can change days dramatically. Also, even from peak opk ovulation time can vary by up to 24hrs and implantation can take between 6 and 12 so there is definitely wiggle room.

I had an early scan at 7+2 due to previous losses and was measuring a week behind - 6+2 but with heartbeat. It scared me but am currently at 34+2 🙏🏼

The level of anxiety in your post made me wonder if you've had previous losses as that is extra tough in early pregnancy. Either way, go gently on yourself and try to take one day at a time. 💗

It's nothing to worry over. At this stage its more of a guesstimate. Even if you know when you ovulated, there's a variance in travel time to get to, and implant in the uterus. You'll have scans that are a bit off during the whole pregnancy ime. Specialist measured a leg bone on dd in third tri and I saw on the screen she was measuring weeks behind. She was measured again a few minutes later after dd moved a bit and measured spot on.

Yes thank you - we had a horrid full term loss with placental abnormalities that could have / should have been spotted.

Hi OP, I work in ultrasound and this is completely normal. No one knows the exact date of ovulation or when implantation takes place. Baby was seen and heart pulsation observed so this was a good scan.

Congratulations 💐

@Commonsense22 so sorry to hear that. What an awful thing to go through. Sending big hugs and lots of best wishes for this pregnancy 💗