Almost all of plan referring to births rejected as a sham (9)
I believe the answer is:
charlatan
'a sham' is the definition.
(thesaurus)
'almost all of plan referring to births rejected' is the wordplay.
'almost all of' means to remove the last letter.
'plan' becomes 'chart' (charting is a kind of planning).
'referring to births' becomes 'natal' (natal means relating to birth).
'rejected' says the letters should be written backwards.
'natal' back-to-front is 'latan'.
'chart' with its last letter removed is 'char'.
'char'+'latan'='CHARLATAN'
'as' is the link.
(Other definitions for charlatan that I've seen before include "fake" , "Impostor, deceiver" , "One who falsely claims to be an expert" , "Person who falsely claims to be an expert" , "Quack, fraud, a flamboyant deceiver" .)