My first was 3hours 51 mins and my second was 7 hours 34 mins (I'm guessing this was due to her being back on back) because my first labour was fast All 3 of My mid wives were stressing to me that I shouldn't stuff around getting to hospital and call an ambulance if I feel things are going too quickly (even told DF what to do If I deliver at home)
so I guess the expectation from a medical point of view is yes the majority of subsequint labours are faster
my girls are 3 years 3 months apart