Sorry to say my 3rd was my hardest by far.
1st - Waters broke at 35 weeks, contractions started an hour later. Time from first contraction, 14 hours, average first birth, was hard but not horrible, had 2 botched epidurals and a spinal headache & blood patch afterwards. Don't know how long I pushed for, it was a while as he got stuck a bit.
2nd - Time from first contraction 9 hours, was an easy labour, she was a shoulder dystocia but it was easily resolved and she had no long term effects. Pushing for a while as she got stuck at the shoulders, was shorter than no.1 though.
3rd - Time from first contraction, 16 hours. Was a very hard labour, was as painful at 4cm as no.2 was at 8cm, got the urge to push way too soon, then the contractions although fierce, stopped dialating me. Ended up on a drip with an epidural for 7 hours at get the last couple of cm's, the midwives said that long on a full drip for the last few cm is unheard of in a 3rd birth. Needed councilling and got PND, the only time I've screamed in pain. Pushing was quick, think I only pushed a few times.
4th - Time from first contraction, 5 hours. The easiest labour ever, most of my contractions were painless, the end ones were only as painful as normal 3-4cm contractions. Only went to get a quick dialation check and left the bags in the car expecting to come home for a few hours... 7 mins after walking through the door dd3 arrived! Totally deserved an easy birth after dd2's, lol. No pushing time was listed as I pushed twice during one contraction and she was born.
No.3 was my heaviest, but she was also my last with my previous partner, no.4 is my first with my dp and was my lightest full term baby.
No.1 - 35 weeks, 4lb 15oz
No.2 - 39+5, 8lb 11oz
No.3 - 40+1, 8lb 15.5oz
No.4 - 40+3, 7lb 9.5oz