I too had 2 miscarriages, and only through a friend and a terrific Priest were able to have burials for my children, both of whom were only 6 weeks. However, this was a very rare situation where a Priest went way out of his way to make the arrangements to have a full burial. The burial is not nearly as important as Baptism.
Maybe someone here knows the exact document, where Pope Benedict XVI wrote on this issue. But the gist is for babies who have died prior to birth, either through miscarriage or abortion, can be Baptised through desire. You see, God exists outside of time, as he is the One who created time. So, now that you know what you know, you would want your child to be Baptised. You are now sorry for not having your child buried. God takes your sorrow and your desire and surpasses time to instill the Graces on your child. Your sorrow and new desire are a beautiful tribute and gift to your child. Cast all doubt and fear away, bathe in the Mercy of Christ, and give Him thanks for the child who is now with Him.
Remember too, God’s commandment for a child is to honor his father and his mother. In Heaven all persons are perfect, and as such obey God’s law perfectly. Your child is in heaven, and he or she is now praying for you before God’s throne, in honor of you. So ask your child to intercede for you, so you can pass through the guilt and sadness, and come into full union with Jesus through His Church.
I know this is a tough time, but I will keep you in my prayers, and best of all your child is keeping you in theirs.