Advance idea from papa about beginning of pregnancy (13)
I believe the answer is:
preconception
'advance idea' is the definition.
(preconception is foreknowledge of something)
'papa about beginning of pregnancy' is the wordplay.
'papa' becomes 'p' (phonetic alphabet: alpha, bravo, charlie etc.).
'about' becomes 're' (common abbreviation for 'with reference to').
'beginning of pregnancy' becomes 'conception'.
'p'+'re'+'conception'='PRECONCEPTION'
'from' is the link.
(Other definitions for preconception that I've seen before include "Opinion formed beforehand" , "Bias" .)