I'd be inclined to think that there could be a link, but that circumstances can certainly change whether there's a pattern, as Cyathea mentioned.

For instance, my mum and I both had posterior bubs with our first-born. Her labour was 30 hours (I'm a bad daughter ), mine was 14 hours (and would have been less if I'd not had such a long second stage). I was very active during labour, ate and drank well, and used water and gas for pain relief. Mum laid on a bed, wouldn't eat or drink (because she was scared to, but wouldn't tell the staff, poor thing), and used no pain reilef. No wonder her labour went on for 30 hours, her body probably almost shut down! I think if we'd laboured in similar ways our labour lengths would have been more similar.

ETA I'm not saying that not using pain relief made mum's birth longer, just that with all the other factors, she must have been bl00dy exhausted!