One of the biggest questions I had when finding out we were expecting was which doctor and hospital. Being relatively new to HK, I asked all my mommy friends about hospitals and pre-natal care. I found this price list on GeoBaby, which was hugely useful and helps you budget for the very expensive bill that will come with your new arrival.
Definitely check out GeoBaby for more advice about having babies in HK. I found the forums helpful when choosing doctors and hospitals and where to shop in preparation for the baby.