What does it mean when they say you have a twin sac? I know I am having twins. Are they in same sac?

Question

went in for ultrasound at 8 weeks 6 days. The doctor told us we are having twins. On ultrasound picture you can see both babies and it says twin sac. does that mean they are in the same sac or what?

Answer 1

Actually, not all identical twins share one sac. I was pregnant with mono/mono's (identical twins in one sac) and had a miscarriage- in fact the rate of mortality is about 50% when they are mono/mono. Your dr would have told you if that was the case.  

Answer 2

I can't say for sure without seeing the ultrasound pics.  If you are having identical twins then they will be within the same sac.  The sac is obvious.  If you are having fraternal twins then there will be 2 sacs.  Good luck!

Answer 3

If your twins were indeed in the same sac, your doctor would have likely told you and may have even sent you to a perinatologist (a doctor specializing in high risk pregnancy).  This type of identical twinning is known as monoamniotic/monochorionic or "mono-mono".  It is extremely high risk due largely to cord entanglement.  You may want to search the web for "twin ultrasound pictures" as a comparison.  Or just ask your doc.  Either way, congrats on your babies and best of luck!