I am not sure about Klang Valley, when my wife visit dr in SJMC they never have any 4D scan... but back in Ipoh my dr scan for my wife 4D with print image 1st time is free, due to the dr said the 1 scan is important, and I pay RM10 to request dr to print out subsequent 4D scan.
She did 4D scan every visit and if you request print out, only RM10 is charged, and my dr did slowly scan and take good picture of my baby using the 4D scan.