Hi Erin, Re: your last pregnancy, Your cannula was tissued( 放錯位置). Normally cannula is not painful and you should be able to freely move around and not feeling “ the cannula “ I think it is safer to have cannula in place in case of emergency ( eg if you had a shock, the medical team can resuscitate you straight away, rather than trying to gain a vascular access when you faint) Sometime emergency can occur within 24 hours after you gave birth ,eg amniotic fluid emboli, that is why the medical team want to leave the annual in your arm in your last pregnancy. All the best with your upcoming delivery. Take care.