Measuring 1 week behind at first ultrasound?

[sevenofnine]

I had a dating scan today. I normally wouldn't have had one, but because this pregnancy had a bit of a strange start, they just wanted to check everything.

I'm supposed to be at least 9 weeks, 4 days. The abdominal ultrasound dated me at 8 weeks, 4 days. The heartbeat was solid at 177bpm.

I'll be getting a call from my doctor as an update later, but it just seems to be concerning to be so far behind at this point. My dates can't be that off!

My last period was 10 weeks ago, on June 2nd. We only DTD once that month, on June 12th (CD11). My cycles can be longer sometimes, so it's possible I ovulated late, but it couldn't have been THAT late considering we only DTD once on CD11!

I got the first very light, almost invisible positive July 2nd, and on July 5th it was confirmed with a blood HCG of 80. Honestly I'm not even sure how I'm pregnant based off of this timetable, it's so strange.

So I can't find any way to make me measuring so far behind make sense.

 

[Sarahcake]

Please don't worry, if the heartbeat was nice and strong (which it sounds it is) then I'm sure baby is fine. I went at 9+4 knowing I was about that, and got dates at 8+3. When I went for my 12 week at 12+3 I was told I was 13+4 so back to my original timescale.

The measurements are so precise, one wiggle and one 1mm off and you end up being out back loads. Their so tiny at that gestation and measuring is such a difficult task to do accurately. I'm confident that you will go to your 12 week scan and regain that week again

Edited to add: that like you, we only DTD once in the month we concieved too, and have no idea how it happened so I, like you, was pretty confident of my dates so I was a bit miffed when the scan showed a week behind too!

 

[sevenofnine]

Please don't worry, if the heartbeat was nice and strong (which it sounds it is) then I'm sure baby is fine. I went at 9+4 knowing I was about that, and got dates at 8+3. When I went for my 12 week at 12+3 I was told I was 13+4 so back to my original timescale.

The measurements are so precise, one wiggle and one 1mm off and you end up being out back loads. Their so tiny at that gestation and measuring is such a difficult task to do accurately. I'm confident that you will go to your 12 week scan and regain that week again

Edited to add: that like you, we only DTD once in the month we concieved too, and have no idea how it happened so I, like you, was pretty confident of my dates so I was a bit miffed when the scan showed a week behind too!

Thank you! The doctor doesn't seem concerned as everything seems healthy and the heartbeat is good... so I'm going to try not to worry!!

 

[Holliems]

With my first baby, I went in at what I thought was 9 weeks but baby measured 8. She's 16 now. 🙂

 

[060509.x]

Like others have said if the heart is beating and the doctor isn't concerned I wouldn't worry.

 

[MindUtopia]

I'm assuming from that you mean they didn't do a vaginal ultrasound? If that's the case, your dates are potentially fairly inaccurate. I had a scan at 8 weeks and they could barely even see baby and definitely not a heartbeat via abdominal ultrasound. It just isn't very accurate at that stage. They obviously didn't have any concerns or they would have done a vaginal scan. Very likely measurements are off by a few days and you might be a few days earlier than you think because you don't know when you ovulated, meaning they dates likely correspond better than they think they do.

 

[xkirstyx]

I was a week behind with this pregnancy at my 7 week scan I was 6 weeks then at the next scan baby was another 4 days a head. Hoping at 12 weeks scan on Tuesday baby will of caught up a bit more. No one was concerned as baby has always had a good heartbeat x

 

[crazylilth1ng]

With my last 2 babies I was a week behind at early scans and we "caught up" both times by the 12 week scan. All is very likely fine

 

[Jcliff]

We couldnt even see a baby until 9w, the machines are so unreliable. Well we just saw a very active baby on Thursday. Don't worry

 

[KandyKinz]

Studies show that ultrasounds in the first trimester are only accurate to plus/minus 5 days though outliars were demonstrated to exist and it's certainly not unheard of for them to be off by up to an entire week. The opposite occurred with my third baby. I was charting ovulation and based on when we dtd I was certain of my dates, but the u/s actually put him a full week ahead which would have been totally impossible! He continued to be a big little dude. Was born measuring 24 inches.

 

[laura109]

Dates never add up. I was put ahead by 5 and 3 days in my pregnancies. Heartbeat is great and that is a good sign. I think they are tricky to measure at this point and itl sll come together at 12 weeks. X

 

[Eleanor ace]

My first scan with my DS I was put nearly 2 weeks back, which meant I got my BFP at bang on 3 weeks and started with nausea and ms before 4 weeks which seemed early. Anyway, he caught up, I think the scan just came before he had a growth spurt!