I'm confused about gestational age vs fetal age etc!

[Monzter79]

This may be a "duh" question...

At my last scan, by my LMP I was 8 weeks +1 day. But I measured 5w5d. Why the discrepancy? If the scans measure age by size, certainly it wouldn't count the time before conception (like you do with LMP dating). Right???

Or, is it more common for the scans to be in line with the LMP?
Does that make sense? I don't quite know how to phrase the question!!!

Has anybody ever had baby with a growth spurt that changed your due date??

Are the scans usually pretty accurate??

I'm due to have a scan again tomorrow... I should measure 7w4d according to last scan, 10w by LMP.

I can't be the only one that doesn't get this!! Will you kind souls please help me wrap my poor little head around this???


Oh, and this isn't anything to worry about is it?

 

[TryinFor1]

Do you know when you ovulated? are your cycles regular?

 

[mummyconfused]

Maybe you ovulated late. Missed up the dates. They go by LMP. So that's odd

 

[Monzter79]

I do not know when I ovulated. BUT, my LMP was May 1. I had sex May 12th 13th, and the 25th. My period should have arrived at LATEST May 28th. (Comes regularly 24-28 days, no more no less.) I did not get a BFP until AF was 2 weeks late and the line was QUITE faint at that time. (June 12th) Last scan was on June 27th and I measured 5w5d.

Sry if TMI. Just wanted to give you what info I have in case it helps you explain this to me! TY I'm confused...

 

[TryinFor1]

You may have ovulated late and conceived with dtd on May 25th. If your period was two weeks late, and that is when you got the faint line, and your scan measured 5+5, then you are on date with your potential ovulation time. I am assuming this is what happened based off what you said.

If you did ovulate your normal time, and didn't get a positive till four weeks later (which is really unlikely), then there might be a problem. However, as I said, I think what I said previously happened and that you are just fine

 

[minties]

Hmm, seems weird. Sounds like you ovulated really late? The sex on the 25th, the timing of the positive and the scan date seem to line up with that.

 

[Monzter79]

So... If I conceived on May 25th, wouldn't my scan on June 27th measure 4w5d?? How does that extra week get in there?? LOL IM SO SORRY YOU GUYS! TY for your patience in helping me understand this.

I thought maybe the 25th was when it happened... It's just SO freakin late in my cycle. Surprised it would have time to stick! (Stranger things have happened.) It kinda makes sense.... We'd tried for 8mos just going by the calendar and bd'ing based on the "likeliest" Cd's. Maybe I've always ovulated really late and just didn't realize.

 

[NHKate]

Hopefully you just ovulated a lot later than you thought. Fingers crossed that tomorrow you'll see your baby in there growing well.

That said... I had a m/c about a year ago where I had an u/s and it showed I was a week behind where I thought I was. I KNEW I was a good week ahead of that because of when I got my BFP. Turned out the baby had stopped growing, and I miscarried later on. In your case, since you didn't get a BFP until a lot later than you would expect, I'd say there's a good chance that you just ovulated late. Good luck at your scan tomorrow!

 

[Monzter79]

I will definitely update you guys with the scan results. I feel very optimistic and I'm excited to see what's going on in there (a little nervous too). Fortunately, I'm not too good at "the math"- so it didn't really occur to me (until my op) that the timeline may be cause for concern. Blissful ignorance saves me from worry ...yet again. ;-)

Fxd!!!

 

[babymamaagain]

My dates are pretty similar to yours. LMP april 29th. BD may 12, 16, and 20. Blazing positive test June 1st. Ultrasound at 7.3 weeks measured the fetus at 6.1.

The only logical explanation is that sperm can chill in the uterus much longer than we like to think!

My doctor is still h

 

[babymamaagain]

Stinkin cell phone! My doctor is still going by my LMP because he said an abdominal crown to rump measurement at 5-6 weeks is rarely accurate. He also thought there may be 2 yolk sacs in there :O

We'll probablu never sleep again if we analyze this stuff.

 

[skyesmom]

i agree with tryinfor1 and totally second what she has written - at scan they go by LMP so your dates should align with that BUT... since you got your BFP only when your AF was 2 weeks late, that really looks like you've conceived on 25th and ovulated super late this cycle... or as you say, you may have ovulated super late usually since you were trying for 8 months with no results.

if you hadn't had any bleeding and cramps, i'd say there is not much to worry since your scan dates align with the conception at 25th rather than earlier. fingers crossed for you and keep us updated!

 

[wannabemomy37]

I think I've got this figured out for you (lol)
BD on the 25th. June 8th (2 weeks after "conception") would be 4weeks pregnant, but you didn't test BFP until 4+4
That being said, just because you BD the 25th doesn't mean you conceived that day, but could have been up to one week later!
I would assume you O'd on June 1st (1 week after BD); making your scan on june 27th be exactly 5+5 (otherwise 6+5 and perhaps a week or less off, which is perfectly normal)

There's no logical way it could have been from the 12/13th BD because you would have then been able to test BFP by the 25th or so. Typically it's only a 2ww so 14 days after O you can get a nice BFP. 4 weeks later would be a very long time and you would then be 6 weeks pregnant.

Hope this makes sense to you!!

 

[wannabemomy37]

This does seem like it's fine from your dates though because by LMP you were 8+1 then a scan should show a gestational age of 6+1 or thereabouts which is only 3 days off

 

[Monzter79]

Just had my scan! Everything looks good- I measured 7w1d. Nurse told me that we're going to have to go by the U/S for my due date. She agrees that I ovulated late and the BD on the 25th was around conception.

She said heart beat looks strong and is right on track @144bpm. Everything is progressing just right (with the exception of my LMP, but we're just tossing that).

The only other thing is- I've been plagued with cramps. She mentioned that she did see some extra fluid around my ovary and suspects that I had a cyst burst- but, I'll have to wait to hear from doctor to get a definite answer. I hope my cramps will die down if the cyst actually burst. That would be fantastic!

TY WBMommy!!! I appreciate you all taking the time to help me figure this out.

 

[NHKate]

Yay! Glad you got good news!

 

[minties]

Cramps are normal , congratulstions!!!

 

[londonangel]

The scan date is more accurate than the LMP. Some of us just ovulate late. With my current pregnancy they couldn't date from LMP and I still haven't had a scan because I took a pregnancy test six weeks after period and it was negative and took one two weeks after that and it was positive! So according to my LMP I am about 14 weeks pregnant or so but actually I know I'm closer to 11 (and that's what my doctor's put in my notes and what my scan date - 18th July - is based on). Try not to worry too much. It's probable that you just ovulated late. If not as another poster has said it could indicate a problem, but hopefully it's just the late ovulation. Good luck!

 

[londonangel]

Ah! Sorry only just saw your update - great news!

 

[Kezzybear]

Hi Hun, I'm a sonographer. Your dates may be out, cycles wrong or ovulated late. By the ultrasound it means that you are approximately 5w5d pregnant. It is still quite early though so see what your next scan shows. Good luck xx