In this region, there's a reason to be childless (4)
I believe the answer is:
area
'in this region there's a reason' is the definition.
'area' can be an answer for 'region' (synonyms). I am unsure of the rest of the definition.
'be childless' is the wordplay.
'be' becomes 'are' (I've seen this in another clue).
'childless' becomes 'a' (I can't explain this - if you can you should believe this answer much more).
'are'+'a'='AREA'
'to' is the link.
Can you help me to learn more?
(Other definitions for area that I've seen before include "Region, space" , "Expanse of a surface" , "Region, zone" , "land" , "Expanse or neighbourhood" .)