The risk of bleeding in the skull, which increases with age, is most directly related to:

The risk of bleeding in the skull, which increases with age is most directly related to shrinkage of the brain. Brain shrinkage occurs as one grow older and is responsible for memory loss and reduced mental alertness. It has also been directly associated with premature death. Brain shrinkage is caused by aging together with its characteristic diseases such as diabetes, cardiovascular diseases, obesity, etc.

They get pregnant at younger ages

It is used to during sexual reproduction between humans