Early scan - not as far along as I thought

[Cafeaulait27]

I had a private scan tonight at what I thought was 6+6, but the sonographer said I was actually around 5 and a half. I have pcos so she said it’s probably to do with that, because I probably ovulated late. I did tell her that despite the pcos my periods are always bang on every 30 days, but she said I still may have ovulated late.

There was a heartbeat and the baby was 2.5mm, she said everything was as expected and it’s one of the smallest she’s done with a heartbeat.

So that’s all good right?

I’m just a bit worried in case the baby is just small and that that means something is wrong ☹️ I thought I calculated my dates pretty well.

My last period started on 2nd August and my next period was due on 30th August, I had some brown spotting around this time which never progressed into a real period so on 3rd sept I did a test and got a very faint positive. I tested again on the 8th and got a strong positive, and I even did a test today and got another strong one.

So... is everything ok here? Should I be worried? Has anyone else ever had it where they’re less further along than they thought?

I know I should feel very lucky because we saw a heartbeat and they said all was well... but I’m just worrying about the size and the dates now ☹️

Hi @Cafeaulait27 sorry to jump on this thread as well as the other but read through your message in full here. I also went for an early scan at 6w exact, and baby measured 2.7mm so I don't think your baby is small for its gestation - based on my similar measurements. Hopefully this helps reassure you a little. X

Doesn't seem anything there to worry about at all! Sometimes you can just randomly ovulate late. There's a heartbeat so that's great, especially at less than 6 weeks, very positive 😊

Ok great thank you guys ☺️

This is my first pregnancy and with pcos I’m super anxious! It’s a lot of information that’s new to me and it’s all a bit overwhelming sometimes. It’s so good to have mumsnet To turn to especially in the early days when none of my friends or family know xxx

I went for an early scan around 5/6 weeks and there was everything there but no heartbeat, went along 2 weeks later and there he was. He's 2 in December. I remember how worried I was early on too. Congratulations.

I had the same thing, my date got put back a week and a half! Like you, I must have ovulated later than I thought. Everything is fine and I’m now 30 weeks :)

@Sleeplessnights1234 ah thank you so much for sharing, so glad to hear it worked out for you!

@Bettie2192 that is really reassuring, thank you! So glad I’m not the only one. And good luck with it all ☺️

So I emailed WTTW about this and got a very reassuring response that I probably just ovulated late and that we are talking very small measurements at this stage anyway.

But then I sat down and properly worked out my sums, and realised if I was only 5 and a half weeks at the scan that means I had to have ovulated only a few days before the date my period was due (which was when I got implantation bleeding). Despite pcos I am on metformin so my periods are in revolt regular, they are every 30 days.

I went back and said this to WTTW and this time they said:

‘ I have just discussed your scan with our clinical lead to make sure I understand the situation fully. She tells me that if you are confident on your dates then the pregnancy should be measuring slightly larger than we saw when you came to us on Monday and that the speed of a heartbeat isn’t a consideration at this very early time in a pregnancy. When we see you for a scan we report on what we can see and unfortunately can’t predict what is going to happen in the coming weeks but we are confident that we have seen an embryo with a heartbeat. In view of the above there is no need and we would be unable to refer you in to the hospital system. In terms of the coming weeks, if you wanted to check that your pregnancy is developing you could book a second private scan either with us or another medical / diagnostic service provider 2 weeks from the date you came to us. If you experience the onset of any pain or bleeding we would suggest contacting your GP or Early Pregnancy Unit for advice (contact details for early pregnancy units are in the wallet we gave you at your scan).

I appreciate that this may not give you all the answers you are looking for and I don’t want to give you false hope or concern, we can just let you know what we have seen.’

Does anyone know what I should’ve been measuring at nearly 7 weeks please? My pregnancy app says 1.3cm at 6 weeks but that seems crazy big? Is that right?!

I don’t know whether they just don’t want to say that the measuring is inaccurate, or they don’t want to tell me it looks bad... or they just want me to book another scan! So confused, but I am pretty sure on my dates that I should be 6-7 weeks now.

Help xxx

*really regular (not in revolt!)

Hey Op,

I could've written your post! I was also dated 5.5 weeks when I should've been 6.5 weeks, also measuring 2.5mm. I was really worried but had a scan yesterday and my dates matched up again, measuring 14.6mm and at exactly the date I thought I should've been (7+6) so don't worry, it'll work itself out again, it's not very accurate as they are just going off the CRL which changes every day xx

@Cafeaulait27 in these situations all you can do is wait for time to pass then rescan and measure growth. It's not fun, I've had similar situations several time. It is 50/50 tbh. When is your rescan?

I think this is one of the issues with early scans - they can only give a snapshot in time. All you can say is at the time of the scan there was a baby plus a heartbeat. They don’t necessarily reassure, and sometimes they cause more worry.

When you have an early scan you are measuring something very small, indirectly (you are measuring an image on a screen and working out a size from that). It can be very inexact and the actual size of the foetus could be quite different. With the dates it is even worse because you then take that measurement, and assign it to a number of weeks based on a median measurement.

There really isn’t all you can do now but wait. It’s not that uncommon for early gestation babies to measure smaller/fewer weeks than one might expect. It doesn’t mean there is a problem.

Sadly, with any pregnancy, issues can and do occur, but you don’t have any information right now that says it’s any more or less likely.

I had a few early scans at the EPU and my dates were all over the place. Every scan was moving my due date forward or back by up to a week! The sonographers weren't worried at all... they said that the measurements they're taking are so tiny that there's a huge margin of error. Even a few millimetres difference can change your dates by days or even weeks. I honestly wouldn't worry about it. Chances are if you had another scan now your dates would change again. WTTW are right, no one can tell you what the future holds, but there's nothing concerning at the moment. Really sorry you're feeling so anxious!

Thank you everyone! Yeah I think I just have to remind myself that it’s so early, these measurements could be inaccurate or the baby might catch up. Overall it was a really positive scan, everything was normal, they just thought it was earlier and I feel like because I put pcos on my scan they immediately had that in their head as to why I was measuring small.

Even when I explained about my periods being regular, the sonographer didn’t really seem to take it in (not criticising her, she was lovely!)

I think I will rebook another scan for 9 weeks, as I’m not sure I can wait another 6 weeks for the 12 week scan!

Really wouldn't be concerned with the measurement being around 7 days out. A few mm at this stage can make a big difference in days calculated which in turn would make the difference in days between what you think you are and the actual measurement seem less concerning. The fact that there was a heartbeat is very reassuring. Many ladies have early scans which doesn't match the gestation they were expecting to be and then have the NHS dating scan which then matches up more with their actual date. When working to .mm at this stage there is a large margin of error. I'm sure if you had a few sonographers scan you in that session, they would come out with slightly different CRLs as 2.5mm is so tiny. I know it's easier said than done but try not to worry too much about this.

I wouldn't worry about your app measurements, I find them to be on the big side! I've had 3 early scans and they've said measurements are spot on for fates but are much smaller than the app ones. The fact you've seen a heartbeat so early is great news, good luck

Thank you so much guys... maybe I just need to chill out!! The heart beat is such a good sign and it’s so early, but it’s so hard waiting especially as it’s my first!

I will keep you updated. I have my booked another scan yet, I think I’ll see how I feel nearer 9 weeks. Part of me thinks - just save yourself the money and just wait for 12 weeks. But then the other part of me is wondering if I can wait this long!

As you start to get symptoms you might feel a bit better. I would caution against too many scans. We don’t yet know the full effects of ultrasound on developing tissues. And whilst we think it to be mostly safe it’s not a given.

@Cafeaulait27 early scans nearly always put you back a few days.

My friends dates were changed so that it would mean she ovulated whilst on her period!

Dates are most accurate at 12 weeks, hence why this is when dating scans are done.

With my DD I had a private early scan and my dates were put back 11 days.
Then when I had my 12 week dating scan the due date was moved back forward by 6 days meaning I was only 5 days behind what I thought myself in the first place.

Please try not to worry, dates aren't an exact science and especially not before the 12 week mark.

Hope all goes well for you, it's such an anxiety ridden time being pregnant, especially in the early days

Thank you everyone! We just told my parents and they are very excited. I’m a bit nervous as it’s still such early day’s but hopefully time will go quickly to the 12 week scan and then we can tell more people. Xxx

@Cafeaulait27 yay how exciting ☺️

I had a private scan at 9 weeks which put me back by 5 days, I wasn't convinced at all and sure enough at my 12week scan my dates where back exactly where k had calculated

@Bobojangles that is good to know, thank you!

After I emailed the clinic asking questions they were very reassuring, and the sonographer actually ended up calling me. She said hand on heart that she thinks everything looks fine and it’s just a younger baby, and the fact there was a heart beat is very promising. So I guess she is pretty sure I’m just earlier than I thought. She said ovulation can be much later as it’s not bang in the middle of your cycle for everyone, but she also said that the dating scan will give the most accurate dates so to wait until then.

We actually got cut off coz my signal was really bad, so she sent me another text saying the same thing. So now I can look at that whenever I’m worrying!