Question about implantation time changing how far along

[Family4Christ]

Hi mamas,

Since there's such a wide variation when babies actually implant (I believe around 6 days?), would that affect how far along you really are? For instance, if two mamas ovulated today and one had baby implant on 5dpo and the other 12dpo, would their due dates technically be a week apart? I know care providers go by O and LMP dates, but I'm just curious if my thinking is right here.

If my babe implanted on 6dpo, when I go for an early u/s, will the dating be off and the baby measure further along?

[finnegansmom]

I doubt it, because the cells are dividing at the same rate from conception.
I've read the *best* day for implantation is 8 dpo and is the most common. Some do earlier and some do later. Once the egg is fertilized by the sperm in that short window of egg viability, the cells are multiplying. Your baby exists before implantation.

[Family4Christ]

Ohhhh, that totally makes sense! That's exactly why I posted this, as I figured I was missing something.

Thanks!!!

[EA77]

I have been told and read that implantation *can* make a difference in dating at early u/s. For instance, I know what day I ovulated with this pregnancy, but it measured 8 days ahead at an 8wk u/s. A couple of those days could certainly be measurement error, but a few must also be due to early implantation. Baby measured 6 days ahead at 12wks and 7 days ahead at 20wks. If I hadn't been adamant about knowing my ovulation date, the hospital would have moved my due date up a week.

[Kidzaplenty]

If I understand it correctly, it would not necessarily matter when implantation occurred, but when conception occured (and by "conception" I mean the moment sperm and egg actually join).

So, if two women O'ed on the same day and then conception was on the same day, but implantation happens on different days, the baby would be the same size.

However, if they O'ed on the same day but conception was five days apart, then the baby would be five days older/larger, no matter when implantation occurred.

I believe there is a "usual" growth pattern at that stage.

[MaerynPearl]

Originally Posted by Kidzaplenty

However, if they O'ed on the same day but conception was five days apart, then the baby would be five days older/larger, no matter when implantation occurred.

if they Oed the same day, conception couldn't be longer than 24 hours apart... eggs only last 12-24 days. If conception does not happen in that time, it will not happen.

Sperm can last for 5 days before O and still conceive... but eggs don't last that long.

[Kidzaplenty]

Hmm. I had always heard that you could DTD 3-5 days after O'ing and concieve. I guess I never thought about it too much. If an egg can only be fertile for 24 hours after O'ing, then that would make them the same size. I wonder how much play there is in that time frame? I guess I will have to do some checking.

[~Adorkable~]

Yeah the 3-5 days thing is just the sperm so just widens the window pre O, there is no known case from some studies I have read of a women getting preggo From sex that occurred over 24 hours after a confirmed ovulation. I'm sure someone has done it, but it's never been seen medically. Since the egg starts growing the moment it gets fertilized, things count from there. Now two ladies who's charts says the same day could really be 18 or more hours different and then one could meet a sperm right away the other 24 ish hours later, so having them look 2 days apart in growth could be correct.