I guess I am late to answer this post, which appeared yesterday, which was my older daughter's birthday. I have three month old boy/girl twins. I delivered them both vaginally. I actually got to the hospital too late to have an epidural (I was already 8 centimeters!) and so I had them more naturally than I intended to. Everything went fine, though I remember asking the nurse, "What will you do if I end up needing a C-section?" because I remember reading that mother's with twins are greatly encouraged to have an epidural because then they will be ready for a C-section if necessary. The nurse said (and I wish I remembered her name because she was a really awesome nurse - she works at Mercy Hospital in Rockville Centre), "Don't even think about it. It won't be a problem."
I too struggled with not being sure about how I wanted to deliver. I had a vaginal delivery (with epidural) for my 3 year old daughter. For weeks and weeks, sonograms showed that Baby A (my son) was head down, but Baby B (my daughter) was head up. My practitioners were a midwife/OB team and the midwife (who delivered my older daughter) told me that for the second twin, it was very possible to deliver a breach baby. This scared me because I was concerned about having a good birth for my son, but risking possible birth trauma for my daughter if she got stuck and her oxygen supply cut off. Predictably, my OB said, "If you want the most stable, controlled situation, you should schedule a C-section."
I was stuck between a strong desire not to have voluntary surgery and fear of having a traumatic birth for my second child. I also was not interested in having one vaginal birth and one emergency C-section, which sounded like the worse of all possible postpartum recoveries.
What happened that helped me make my decision is that my daughter somehow turned head down in the last couple of weeks. Suddenly without the breach baby to worry about, I knew I wanted to try to have them naturally. I decided I was willing to risk the possibility of an emergency C-section rather than to schedule myself surgery just out of fear.
As it was, I will say that the second twin was harder to deliver than the first. I joke that she pushed him out and then decided that she was so comfortable with all that extra space that she wanted to stay awhile. The doctor, midwife, and nurses had to do a lot of pressing to get her low enough for delivery. There was one hour and 9 minutes between the birth of my two twins (not all that time was pushing - but there was a lot more pushing to get her out - and luckily there was no concerns about her heart rate decelerating or anything else).
Based on the reaction I got, I don't think the hospital had seem many vaginal twin births. It is not very common, but I have to say that I whole-heartedly recommend it for a situation like mine where the mother has given birth vaginally before, both babies are head down, and there are no apparent complications.
I wish you all the best! Enjoy your babies. Make sure that you have lots of help set up for the early weeks when they are home, because having two little ones is altogether different than just one! Oh, and if you breastfed your older children and want to breastfeed your twins, don't let anyone tell you that you can't do that either. My only goal was to give it a real try during the first month and it worked so well that I have never needed to supplement with formula.
Good luck to you!