Yeah, what NDH said! Except posterior is when baby is head DOWN (as they should be) but with their back against yours, rather than their back in the 'hammock' of your belly. It is harder to birth them that way, but not as bad as breech (head up/feet or bum first!)
But yeah, any drugs you get will be absorbed into your blood stream, and therefore into the baby's too, though usually to a lesser extent of course! And I dunno, I'm just not keen on drugs unless they're necessary personally anyway, and that includes even simple paracetamol, but that is just a personal thing that I'm not big on drugs and chemicals and stuff.
I was open to having pain relief if I wanted it though! I had the gas & air right there ready for me if I wanted it, but I never used it at all. My labour was hard work, but quite cool. The birth was freeking awesome and totally pain free with the endorphins my body was producing!
Sometimes drugs can cause a snowball effect where one drug isn't enough, or has worn off, and so they go up to the next level, and if it escalates to an epidural it often then snowballs into a caesarian section. Not always, obviously, but that is another risk that is associated, though I'm not sure what the actual stats are!!! And when using synthetic drugs it counters the bodys ability to control the pain itself - it is a proven fact that the mind and body, is far more powerful at controlling pain than ANY drug is, and drugs do interrupt that process.
And yeah, it wasn't anything about trying to be better or anything, but it was a *personal* thing that I really wanted to have a natural birth, cos I trusted (I hoped) that my body could and would do exactly what it needed to. It was a personal goal that I wanted to do if I could. Like I said, I was still open to having drugs if I needed it, but I simply didn't need it. The KEY thing I kept telling myself when it was feeling "too hard" was that my body WILL NOT and CAN NOT do more than I can cope with, because my body IS me! It will push me to my limits, but it simply CANNOT make me/itself go beyond what can be coped with. And yes it hurt somewhat, but I can cope with 60 seconds of hurt and then rest, it's not actually hours of continuous pain, it is in surges and waves. It's very cool really.