Was Isaac born to Abraham and Sarah without physical contact between them?

I believe that Isaac was the legitimate seed of Abraham, but have a doubt whether he was born out of normal physical contact between Abraham and Sarah. Because Romans 4:19 says that his body was as good as dead then. Yet he believed that God would keep His promise. 

Then the question is, did God miraculously cure Abraham's infertility & menopause condition of Sarah in order to beget Isaac, or did God miraculously form the seed of Abraham in Sarah's womb without Abraham's physical contact with Sarah by His almighty power?

Romans 4:19

NIV - ¹⁹ Without weakening in his faith, he faced the fact that his body was as good as dead - since he was about a hundred years old - and that Sarah's womb was also dead.

Clarify • Share • Report • Asked February 13 2015 • Arun Kumar Supporter