Why I do not get the margins right on all pages when I print A4 size pdf file as A5 size Booklet through Acrobat Reader?

My requirement is printing a 40-page A5 size booklet. I prepared document with page set up for A5 size booklet in Word Office 365, converted to pdf file on CutePDF Writer and printed hard copy through Acrobat Reader; the margins in the print out do not appear as set in docx file.

So, I reset my 40-page document to A4 size docx file with the following page layout; Paper Size - A4, Orientation – Portrait, Mirror Margins, Inner Margin – 3.5 cm, Outer Margin – 2.1 cm, Top & Bottom Margins - 2.8 cm, Header & Footer – 1.4 cm from edge of paper, 0.8 cm space (Gutter) is included in Inner Margin.

I converted the docx file to pdf file on CutePDF Writer for A4 size print output, then printed the A5 booklet through Acrobat Reader. I find that margins are not scaled down as the text is done. Don’t the margins also get scaled as the text (font size gets reduced to suit A5 size print output)?

Can anyone help me to get the scaled down margins right on all pages? Thank you.