There are other methods. If you have the formatting display switched on (via the ¶ symbol on the Ribbon's Home tab), you can easily see what's causing the gaps. It could be empty paragraphs, manual page breaks, Section breaks, etc. If there are manual page breaks and/or Section breaks causing the gaps, then you need to consider whether deleting them is appropriate. Obviously, doing so will cause material from the next page to be added to the end of the current page. It may also cause changes in formatting and the loss of headers/footers if you're not careful. An alternative approach might be to change the page size to something smaller (and/or increase the font size), so that the text fills the page, then use Word's 'Pages per Sheet' option from the Print dialogue to print two or more pages per sheet. You can do the same kind of thing with the original PDF, without involving Word at all, and be assured that the formatting will remain the same as the original.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]