movie where a demon impregnates a young woman named something like samuria

A young couple, Rosemary and Guy, moves into an infamous New York apartment building, known by frightening legends and mysterious events, with the purpose of starting a family.

Young Rosemary Woodhouse and her husband Guy move in with a rich couple, who soon take an unusual interest in the Woodhouses' attempts to have a second baby after Rosemary miscarried the first one. Guy soon has unusual success and Rosemary becomes pregnant, but it becomes clear that the two are connected and that the pregnancy may not be all that Rosemary hoped for...