2 week difference in twin embryos?

[Ceasnake]

Nothing about this pregnancy so far has been straightforward (see this thread www.mumsnet.com/Talk/conception/1331627-Where-the-buggery-fuck-is-my-period
for the precursor).

I went for a dating scan today thinking I was about 13 weeks along. The sonographer immediately spotted that I was nothing like that far gone and in fact the scan showed an 8 week embryo. Then she found another one! This one only measured 6 weeks though. Both had heartbeats.

Having thought I was safely out of the first trimester, I now have to wait a chuffing extra month to see if both keep developing (that's the next scan date).

Has anyone else had this size/age differential in twins this early and did it turn out okay? Why would one be so much smaller/younger? Surely they can't have been fertilised two weeks apart?

They can have been fertilised 2 weeks apart :)

Apparently there's loads of twins (in the world) with different fathers!

Ok, not common, but does happen :)

www.dailymail.co.uk/news/article-1378184/Woman-discovers-twins-sons-DIFFERENT-fathers-The-Maury-Show.html

www.dailymail.co.uk/health/article-1177120/The-incredibly-rare-twins-conceived-week-apart.html

Superfetation:

Superfetation happens when Mom is already pregnant when she ovulates and releases another egg - sometimes as long as 24 days after the first egg is released. A different sperm then fertilizes the second egg. While the twins have different conception dates the babies will most likely be delivered at the same time, although they may be different sizes and at different developmental stages.

Firstly congratulations on your pregnancy! It can be so scary when your dates don't match to what you think they should be, but the fact that both babies have heartbeats is a really great sign.
I am living proof that twins don't have to be conceived at the same time, I have a twin brother who was conceived almost 3 weeks before me! we are now 26 and neither of us have had any health problems. We were both born at healthy weights myself at 5lb 1 and brother at 6lb 12 (mom must've been huge!) we were born at 37 weeks (for him).
All I can say is try not to stress too much... I know that's tough with any pregnancy, even more so with multiples, but there is every chance things will progress smoothly.
Good luck. Xx

Thanks for your responses, I had Googled 'superfertation' but it seemed so incredibly rare, I thought it couldn't possibly have happened to me.

They both have the same father; that's one complication I don't have to worry about, thank God :)

Thinkingpink, what a fascinating story, thanks for sharing that.

Wow, how exciting! Congratulations!

Congratulations! I have a friend whose twins were conceived 2 weeks apart. When they were born one was noticably bigger and more 'to term' than the other, but they are both fine now.

Wow, what a surprise and how exciting!! Great they both look ok, try not to worry too much. Though do come and join us with the multiple worries of multiple pregnancy on the twins thread! (Ante-natal clubs, called Twins Club 2, all welcome).

The only bad thing is being put back a month, gutted!!! I will cross my fingers for you and hope to see you on the twins thread!!

Congratulations again.

Thanks, have hopped over and said hello!