Aiyoo, 12 jam memang kurang sikit for an 8-month-old, biasanya they should be getting around 12-16 hours including naps, so I'd definitely check with your paediatrician to make sure everything's okay. A few of my mum friends also noticed their babies weren't sleeping enough and it turned out ada teething or reflux issues yang boleh diaddress, so worth getting it checked out rather than worrying sendiri!