PDF Printing & Custom Page (Sheet) Size

[COOPER NORMAN 0]

My MS Word Document is formated for 6 x 9 page size; dictated by the publication requirements of the end product.  When I print this manuscript to Nitro Pro version 13  the page 6 x 9 page size is indicated under the page setup prior to printing; but the PDF that is produced on an 8.5 x 11 page and I can not submit this for publication.  How do I get Nitro Pro to print the page size correctly in the PDF output?