I don't know the whys about cervical swelling but I can relate my experience with it.
for DD#1 labor started like gangbusters. Soon I was having 3 minutes apart, 1 minute long and we went to the hospital (yeah, I know). So things progressed 1 cm/hour until they insisted I get an IV finally. At that point I was 8 cm and almost immediately things started getting excruciating. Like constant sharp internal pain. I was totally debilitated, nauseous, lying down, now on an IV, having been up all night and now drifting in and out of consciousness. I seriously thought I might die from the pain...part of me was hoping to, even, just to get it over with.
I really wanted a natural birth, I walked around as much as I could, (like, for 5 minutes once) tried to eat (threw it up). After 8 hours of this hellish agony, I agreed to their recommendation of epidural/pitocin (doc had said it would help the pain, relax me and help the swelling, and get contractions back on track since the intense pain and hormones had made them irregular and weak). DD was healthy, born vaginally at [3.075 kg] 6 lbs 12 oz, kind of small so I know it wasn't distocia. I was damn lucky to avoid a section.
Fast forward to birth #2. Had done a lot of reading and soul searching. I read: Unassisted Childbirth, The Power of Pleasurable Childbirth, and lots others and basically came to believe that the SETTING was responsible for my birthing problems with dc#1 (the setting, but possibly also in conjunction with too much prenatal care/ultrasounds and the accompanying worry) .
With #2 I birthed at home, labored and birthed in the tub, with my mom and husband here. It was a simple 4 hour labor, start to finish, very calm and quiet and except for a major whiny and tearful breakdown moment of "this is a mistake, I can't do this, it hurts too much, I need something for the pain, my body's screwing up again
" (my mom
said, "Hmmm it might be too late for that. I'll bet you're in transition. Here, have 6 drops of rescue remedy." and just a contraction or two later I was pushy and feeling all wonderful again. The pushing stage was about 45 minutes. Easy gentle pushing but doing the job. Still in the water leaning back. And before we knew it, he was crowning, and then was that WHOA ring of fire, then I flipped over to hands and knees and because of gravity I guess I pushed a little too hard, and his head was born! (minor tear) DS was wiggling and turning, and making sweet little wheezy/grunty noises, and on the next contraction his body was born.
So my guess is that you should not worry about having the same problems this time around even if baby #2 is big. You're a different person. Probably even more educated and confident in your body's abilities. And you're making different decisions.
Oh I just reread your writings...I ALSO had a cervical biopsy in 3 places when I was...let's see...22 or so? (I was 34 giving birth the first time). WOW could that be part of the picture?