If we enter IVF/prescription costs for our 2016 return, do we have to do the math to enter only what is more than 10% of our income, or will TT do that automatically?

The threshold for medical is any amount exceeding 3% of your net income...and yes, enter all your expenses.  The software will complete the calculation for you.  In fact the full amount is also recorded on the tax return.

http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns300-350/330-331/menu-eng.html#...