I have read about some women vaginally birthing brow presentation and deflexed positioned babies - deflex isn't a brow presentation, but their chin isn't tucked into their chest, so the overall head circumference is larger. These women had a second stage that lasted a few hours because that's how long their body needed to be able to dilate that bit further. Also don't forget that a baby's skull isn't a solid piece of bone, it will mould and shape as much as it needs to so it can be born. My first bub had amazing moulding on his head - he looked like a conehead LOL and at birth his hc was only 34.8 but I reckon if they had of measured once the moulding had gone down the following day that his hc would have been a lot larger. Plus the second stage lasted for 1hr20mins and I think that I needed that long to allow his head to mould the way it did. Seriously hun, you will be fine!