How much of the layout do you need to reproduce in the Word file? Are there graphics? Are there text frames that are not part of the main story? Is the text from page to page linked across one chain of text frames?
If you want to export the text of the main story with formatting preserved you can export to RTF (Rich Text Format) by putting the insertion point in the story then going to File > Export. This will save the formatted text in a document Word can open. It will preserve most or all paragraph and character formatting, but only for the selected story. Master page items, other items in other pages, graphics, and layout won't transfer because those are not part of the text.