The example sentence:

Women have entered the labour force in large numbers, a fact which has strongly affected the personal lives of people of both sexes.


At first, I would like to put a number into the two sentence like below.
1) Women have entered the labour force in large numbers
2) a fact which has strongly affected the personal lives of people of both sexes.

It doesn't have a connection word like 'although', 'because', 'and', 'but' etc. I wonder How I can understand the relation between 1) and 2).

Please give me the answer.