[jucyntux] Evolving against late onset diseases

We wait to get married and have children later in life.  This will causes evolutionary pressure against fatal genetic diseases whose symptoms (especially the symptom known as death) develop only later in life.  What will be the effect?  What diseases will be most affected?

Bipolar disorder, with its associated increased suicide rate, often develops in the late teens, which is later than typical first childbearing age a few generations ago.