i m not very sure if KK have prenatal pkg.. But they do pkg only starts from 12 weeks preggy onwards. If you are visiting a subsidy gynae in KK pls take note you may not be arrange to see the same gynae each visit ( not very advisable due to bad experince from my friends ). Yes no matter which hospital you delivery have to pay upfront cash as deposit ( admission fees ) but refunded after medisave deducts ( pls not medisave deductions and caps so additional will deduct from your deposit if not sufficient still must top up).
Prenatal pkg usually dont include detail scans, supplements.
If you prefer to visit same gynae and same gynae to deliver, look for a private doc ( KK also have but dont know good or not ) from KK or outside. Subsidy gynae in KK cannot choose when you go for visits check ups and delivery. Oh ya for subsidy delivery is done by mid wives not gynae.