Blood clots cause problem birth, award included (7)
I believe the answer is:
thrombi
'blood clots' is the definition.
(thrombus is a kind of blood clot)
'problem birth award included' is the wordplay.
'problem' indicates an anagram.
'award' becomes 'OM' (order of merit).
'included' is an insertion indicator.
'birth' with letters rearranged gives 'thrbi'.
'thrbi' placed around 'om' is 'THROMBI'.
'cause' is the link.
This may not be correct. It may belong to another bit of the clue.
Can you help me to learn more?
(Another definition for thrombi that I've seen is " Blood clots".)