Very interesting article! I had this issue with DD2, who was posterior (undetected until her head was born), and it made my labour SO much harder. I couldn't push efficiently and after 45 mins of constant contx and bearing down, she hadn't moved into the birth canal at all because she was caught on the lip (I had ARM after reaching 10cm on my own with no worries, it was just that stupid lip that caused problems!). Whether this was due to her facing the wrong way or not, I don't know, but it was very painful and DD2 didn't budge until the midwife reached in and pushed the lip back to free DD2 - after that it was all guns blazing, but sheesh... such a little thing, caused so much panic! Something to be aware of if you weren't already, mums