What is a term for people in the same life situation?
Like, people who have the same health issue, or pregnant women.
Perhaps you mean a cohort?
cohort n. sing. or pl.
2 • a group of people banded together or treated as a group: a cohort of civil servants patiently drafting legislation. • a group of people with a common statistical characteristic: the 1940–44 birth cohort of women.