Wife initially needing assistance to give birth (5)
I believe the answer is:
whelp
'give birth' is the definition.
(I've seen this before)
'wife initially needing assistance' is the wordplay.
'initially' says to take the initial letters.
'needing' says to put letters next to each other.
'assistance' becomes 'help' (synonyms).
The initial letter of 'wife' is 'w'.
'w'+'help'='WHELP'
'to' acts as a link.
(Other definitions for whelp that I've seen before include "Perform deliveries without assistance" , "Boy!" , "youngster" , "Give birth to (a puppy)" , "Cur" .)