Unders do make size slightly smaller as the muscle is pushing them down!but unders do gradually get a bit bigger as time goes on due to the muscle relaxing!I’d go for bigger size as I had 410 partial unders, I’m size 6 and was 32a before and although I measure at a 30f now they dnt look any bigger than a d/dd as implants look smaller than ‘real’ boobs!trusat your surgeon with what size they suggest as they are the experts and are paid to give u the results you want!what size are you now?xx