Hi there...
I gave birth naturally and had no jewellery on, mainly as I only wear a chain, earrings and wedding/engagement rings...I took my necklace and earring off as I didnt want to loose them in hospital and my rings stopped fitting during pregnancy anyway. But am sure if you have body piercings the midwife may advise to remove them...
As for C-sections I work in operating theatres and have done for sections too. Any piercing or jewellery HAS to be removed or taped if you cant get it out or off...but they will make you attempt to remove them first especially tongue studs (due to if you need to be put to sleep quickly they dont want them to get in the way or potentially go down into your lungs if they came out or you choke on them) etc....if not just a piece of surgical tape can be put over them so they dont snag and hurt you and also due to the use of electrical equipment they dont want to burn you at a piercing site.
I recomend taking out piercings if you can though...
Emma.,xx