I'm very sorry for you and your wife's loss.
I signed up just now so I could try to let you know what your wife can expect. I felt I had to share this with you because when I went through my miscarriage I had no idea what to expect.
My ultrasound at 6 weeks showed no heartbeat. The doctor said because of my fibroids that could be the reason he was not detecting the heartbeat. (I think he just didn't want to break the bad news to us, but I really believed everything was going to be ok) My husband and I began to pray and hoped that the next visit the dr. would see the heartbeat.
A long story short; I was 11 weeks when the miscarriage started. I started to spot, that lasted about a day. Bleeding became heavier next day. My dr. said I could stay home through the miscarriage. Your wife can either go to the hospital or stay home, it is her choice.
She will bleed like she has never bleed before. She will cramp in her lower back and stomach and it is painful. It will feel like early labor pains. Tell her not to be afraid, just be prepared and to pray. Please go to vitamin shop or some other vitamin retailer and purchase chlorophyll. Also get plenty of orange juice. She should mix the choloraphyll and juice together and drink it through out the miscarriage. This will keep her iron levels up with all the blood loss. (Chlorophyll isn't the best tasting but really will help with the blood loss, take at least 1/4 cup chlorophyll per day during heavy bleeding. Brand: De souzas is best tasting)
On the second or third day of this, she will pass your precious baby. You will not see anything other then a little round sac. She will pass a lot of blood clots, but the sac holding your baby will be different. Once she actually passes your precious baby, the cramping stops and the bleeding calms down a little. Please, maybe talk to your priest, research now, and pray about what you will do with your baby once your wife passes the sac.
All of this can be done at home. She will miscarry naturally, our bodies know what to do.
But, if your wife feels more comfortable being at a hospital during this than that is what she should do. The dr. will tell you if the bleeding gets too bad to go to the hospital. You can always take her to the hospital at any time during the miscarriage. Just know the bleeding will be extremely heavy.
That is a summary of the physical part, the emotional part is the hardest. My family will keep your family in our prayers. Again, I am very sorry for your loss and I know the Blessed Mother will be right at your wife's side.
I had two children before my miscarriage and one after. Everything is going to be ok. I don't know if you have seen Mother Angelica's old shows on EWTN, but on one of her shows she was talking to someone who had a stillborn baby and Mother Angelica told her that miscarried and stillborn babies are in heaven being great advocates for us. I believe that, and I talk to my little one, asking him or her to whisper in Jesus' ear for certain intentions for our family.
Take care. I pray God keeps you and your wife in His hands during this very difficult time in your lives.