Baby measuring 2.4 weeks ahead at 12 week scan

[BabyBorn]

Hi ladies,

Looking for some insight to help me understand what is going on here.

Since my mid 20’s if I was not on any hormonal contraception, I have always been able to feel the exact time when my body tries to ovulate. Back then it sometimes used to take up-to 3 days for the egg to be released which was really painful. I got pregnant at 26 and knew when I ovulated. Scans put DD2 5 days ahead of my dates. This was fine as it was only 5 days. DD2 was impressively born on the date my husband and I were expecting her, which was 5 days after the EDD the hospital issued. She was born weighing 9lb 1.

In June 2019 I came off my contraception pill as it has never agreed with me and I was getting horrible side effects. I downloaded the Clue App to help me log my cycles. I have been logging my cycles ever since.

Fast forward to now, I am expecting my 3rd baby. Went for an early scan as have had a previous ectopic rupture so wanted to check the pregnancy was in the correct place, which thankfully it was. The sonographer said I was measuring 2.2 weeks ahead of the dates I gave them. I wasn’t overly worried as I just thought that the scan at that stage of pregnancy might not be that accurate and the dates would balance out at our 12 week scan.

Went to our 12 week scan last Wednesday and sonographer has put us 2.4 weeks ahead. I told her I was only just 11 weeks on that day according to my dates. I explained that I had gone from the date I had my ovulation pain and the date was exact. We had DTD 3 days before so the sperm would have already been waiting for the egg to be released. After this scan I was given the sonographers paperwork and my pregnancy notes and given a slip to give to the midwife who I had to see after the scan that said “please take your notes to the midwives office for a growth scan to be created”. Midwife have me a growth chart that showed my DD’s birth weight and showed she was on the 94th centile for her birth weight. She then explained that this time they wanted me to do the Glucose test to check for Gestational diabetes! She was 9.1 not over 10lbs which the NHS state the minimum size is before you are offered the Glucose testing.

I totally understand the fact that all babies are different sizes and that scans are based on average sizes at that point in pregnancy and are not 100% accurate but I have never had such a big indifference with dates like this before.

I feel that my dates are correct but wondering how both scans could be so out? The scans were 3.5 weeks apart. Can anyone shed any light on this at all?

[quote BabyBorn]@WinterSpringSummerorFall

LMP was 1st of October
DTD 10th of October
I ovulated on the 13th of October
Implantation spotting 26th and 27th of October.[/quote]
So counting from 1st October you're roughly 13 weeks which is what the scan dates match.

@DarlingDarwin when I questioned it at the time she said that was the size the baby was measuring. I saw her drag the mouse over to do the measurements and she said I will check again. she then asked me when my LMP was and she laughed and said oh,
It goes beyond your LMP.

What did they decide your EDD is? From your ovulation date it would be 6 July and from LMP it's 8 July. Did the scan put you anywhere near those dates?

I only got halfway through your post and immediately thought GD.

The sooner you are tested the better for you and baby. I had GD, diagnosed at 33-34 weeks and in any future pregnancies I will be checjed over and consultant led from early on.

If you have it, the management will be changing your diet and failing that, metformin, increasing the dose and eventually insulin. You will have a device to monitor your levels several times a day. For most women GD goes away after the birth but you and baby need to be checked over re glucose levels (baby after birth, you 6-13 weeks pp). You will be at increased risk of type 2 diabetes for life - it's not a guarantee, but just be mindful of it as 1 in 2 women end up with it if they're not careful.

It's great you will be checked over soon, undiagnosed GD can be dangerous to you and baby - baby would likely grow too fast and it could lead to many negative outcomes during pregnancy or birth or afterwards, I won't be scaring you with that because luckily with an early diagnosis you'll likely avoid all of that. All the best and slow down in this pregnancy if you can, GD can be a rough ride sometimes, but if well managed you'll be fine xx

Oh hang on, I only just saw your update. Yes, you're 13 weeks, it's counted since LMP date, not ovulation date, you know this, right?

I know exactly when I conceived but dating scan put my due date a week ago earlier. They really need to do new research to work out a better way of predicting due dates.

OP it's all guess work. Honestly, baby will come when baby will come, it's why they used to say baby will come in March or November because predicting the exact date is impossible.

Just concentrate and your maternal health and babies health. If the scans are saying he/she is healthy with no complications, if all your tests come back fine. Enjoy your pregnancy.

I had no idea when DS was conceived, I had all my scans he was healthy. They said he was due August xth, I took no notice of it, I just planned for "In August" he came mid August happy and healthy. Job done as far as I'm concerned 🤷🏻‍♀️🤣

Thanks ladies. So many replies and can’t keep up! Lol.

Thanks for the input. It’s been a while since I’ve done all this but it wasn’t explained like that at the scan. She said that baby was measuring ahead of the dates I gave and she gave no explanation. I was anxious as wanted to see if everything was ok with the baby so didn’t press on about it.

So if I add on two weeks and take it from my LMP then I am due July 8th from my dates and they are 6 days out.

And also, I know when I conceived DS but my EDD was 1-1.5 weeks sooner so that is quite normal.

@escapingthecity I understand what you are saying totally. Thing is not everyone is lucky enough to know when they ovulate so makes things tricky for the people that do. I feel I know my body and cycles so well. When I look at my clue App and see all the logs on there it looks like a textbook conception. Even the implantation spotting is bang on within the time frame, then they have to whack on an extra two weeks and confuse it all x

I knew exactly when I conceived as I was tracking but as it goes off LMP I was 3 weeks pregnant when I found out and hadn't missed a period yet. I liked that I got the 2 extra "free" weeks but it did take my husband abit of getting used too! Congratulations op

Six days out is normal, nothing to worry about. I had IVF so I know the exact date of fertilisation and when we had the transfer and my due date still got moved forward four days at my 12 week scan :)

@BlwyddynNewydd2022 oh definitely baby will come when ready. I was panicking thinking if dates were over two weeks out they would be trying to convince me to be induced! Which I don’t want at all. My other two came when they were ready with no intervention.

Thanks for all your input ladies.

[quote BabyBorn]@escapingthecity I understand what you are saying totally. Thing is not everyone is lucky enough to know when they ovulate so makes things tricky for the people that do. I feel I know my body and cycles so well. When I look at my clue App and see all the logs on there it looks like a textbook conception. Even the implantation spotting is bang on within the time frame, then they have to whack on an extra two weeks and confuse it all x[/quote]
Because it's all about "cycles" so they always start your pregnancy at the first day of your cycle.

The first day of your period is actually the first day of your "pregnancy" yes it's odd, but it's just how they do it.

It's why I wouldn't get hung up on it all, baby will come when baby is ready to come. You can't control nature. They will allow you to go to 42 weeks because they know dating can be "off".

@MrsRubyMonday I find it all so fascinating. I wonder if your baby will come bang on the dates you would expect!

Thank you @sageandbasil my husband gets annoyed with it too! 😆😂

@GinnyBee they put me at July 2nd x