The most common and most likely answer to this crossword clue is the 9 letter word MATERNITY
M
A
T
E
R
N
I
T
Y
Buddy explains!

The straight part
We know that "labour plays a big role in this" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case labour plays a big role in this = maternity.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MATERNITY mean?
MATERNITY noun- The state of being a mother; motherhood.
- The state of being pregnant; pregnancy.
- A ward or department in a hospital in which babies are born.