It was unclear whether pregnancy specialist and top surgeon had treated them successfully (8)
I believe the answer is:
obscured
'it' is the definition.
The definition suggests a singular noun but the answer is not.
'unclear whether pregnancy specialist and top surgeon had treated them successfully' is the wordplay.
I cannot quite understand how this works, but
'unclear' could be 'obscure' (I've seen this before) and 'obscure' is present in the answer.
'had' could be 'd' (in contractions e.g. 'I'd', 'you'd' etc) and 'd' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'was' is the link.
Can you help me to learn more?
(Other definitions for obscured that I've seen before include "Concealed from view, made indistinct" , "Veiled, hidden" , "Overshadowed or eclipsed" , "unnoticed" , "Good news from clinic about schoolboy no longer" .)