From what I've generally heard, the glucose test (OGTT) and growth scan for KKH private patients tend to add up to around a few hundred dollars depending on whether other tests are bundled in that visit. A friend who delivered at KKH privately mentioned her individual scan visits were roughly in the $120, $150 range without any subsidy, though that can shift if your doctor adds on extras during the same appointment. It's worth noting that going through a polyclinic referral first can bring costs down quite a bit versus walking in directly as a private patient, so that trade-off is something to consider early. The safest move is probably to just call KKH's billing counter directly and ask for a breakdown, they're usually quite transparent about the estimated charges so you won't get a shock later.