It isn't so much to be blamed on Islam directly but more on the social stigma that gets attached to a raped woman in the culture.
Women who get raped have always suffered from social stigma, even in the western cultures, specially in Greece, Italy, Portogal, Poland, Spain and most of East European countries, but they are not killed or accused of adultry. In many caes, they are helped by nuns. I personally know about few women who would shelter women who were raped or became pregnant out of wedlock. Something like this will never happen in any Islamic country. On the contary those women will be killed along with the unfortuante girls.
It is only in Muslim countries that women who are raped are thrown in jail or stoned for the crime of "adultry".