success mentioned...so confused about my surprise twin!

[mb1981]

I am beyond confused here. My first beta was 195 at 14dpo, second one only doubled 83% in 2 days, third beta just barely doubled in 2 days.

My RE is at Cornell and very accomplished. He did an ultrasound at 5w4d and saw one gestational sac. He looked around for another sac, since I implanted two blasts, but there was only one. I thought I saw two yolk sacs in the gest sac (and looking back at my ultrasound photo I am almost certain I see two yolk sacs) but I stupidly didn't mention it to the doctor as he clearly pointed out one yolk sac.

My next ultrasound was yesterday (6w5d) and there were two gestational sacs, each with a baby and each with a heartbeat (125 and 115). The doctor said they are definitely identical twins since there is no way he could have missed a sac that size (since it measured fairly on time, not very behind). My question is this: If they are in two separate gestational sacs, even if they were identical, shouldn't they have implanted separately (since everything online says di/di identical twins- meaning they each have their own gest sac and placenta- have to have split on day 2 or 3 after ovulation and implanted separately? Especially since I implanted blasts on day 5? I don't get how the embryologists wouldn't have seen them splitting and still doesn't explain why I had one sac at 5.5w and 2 sacs at 6.5w. Has anyone heard of a gestational sac dividing into two between 5.5 and 6.5 weeks? I just don't know why they are so sure they are identical and not fraternal (concerned since identicals are much higher risk than fraternal)

Sorry for long post. I am beyond confused.

[baylorbear33]

Hey there... I thought I would share my experience. I had my first IVF (fresh cycle) last May. We transferred two 5-day blasts (one of good quality and one of poor quality). Because of this, I though for sure we had lessened our chances of multiples; however, when I went in for my first ultrasound at 6w4d, they found two heartbeats and suspected a third. At my 8w ultrasound, they confirmed that I was in fact pregnant with triplets. Not just triplets, but identical triplets. One of our blasts didn't implant, but the other split twice. There was only one placenta, but each baby was in its' own gestational sac. This was a very rare pregnancy and proved to be very difficult as well. The third baby was lost shortly thereafter and I continued with an identical twin pregnancy. The third baby was never absorbed or mis-carried and ultimately kept growing and taking on fluid although it had no heartbeat. We were diagnosed with triplet-to-triplet-triplet transfusion syndrome. I lost the pregnancy at 19 weeks due to extremely early pre-term labor, and a quack of a doctor that pushed us into an amniocentisis that was unnecessary, but that is another story. I tell you this only to let you know that even if you are pregnant with identical twins, the fact that they are in their own gestational sac is great news. If they are sharing a placenta, then you are at a higher risk for transfusion syndrome and you will need to see a specialist throughout your pregnancy. The way my doctor explained it to me at the time was that the fact that there was one placenta and very thin membrane between the babies indicated that it was identical triplets. With fraternal, you see separate placentas, sacs, etc. I hope this helps a bit, but just stay on top of things with your doctor(s) so that you have a safe and healthy pregnancy.

[mb1981]

baylorbear- I am SO sorry for your loss. How awful and devastating.

I really appreciate your story and your input. I did not realize that identical twins in their own sacs may still share a placenta. The nurse I spoke to (who obviously didn't know what she was talking about) told me that if they have two separate sacs, they will each have their own placenta. Thanks for clearing that up. I just called my doctor to ask him to confirm that they are in two separate gest sacs and whether he can tell if they will share a placenta or not.

I am seeing one of the top high risk "twin doctors" in Manhattan so i will be in good hands.

After getting over the initial elation, I am incredibly scared. Identical twins are really at risk for so many different problems.