yes it's possible. my client delivered at Mt Elizabeth Orchard at wk 27+5 due to placental abruption and I help her to contact the govt hospital for transfer. Kkh didn't have space, so bb was sent to Sgh at day 5. do note that, you will need to fork out ~2k cash for the ambulance + medical staff to accompany the bb to the govt hospital.
hope it helps. let me know if you require more details.