if you go to any MCHC (母嬰健康院) /hospitals with G&OB department at specific time, you can attend free seminars, which play simple movies. Different MCHCs/hospitals would have different opening hours and seminar schedules. http://www.fhs.gov.hk/tc_chi/centre_det/maternal/maternal.html
You can also contact the hospital you will give birth and check any seminars.
I'm attending the one in Sanatorium Hospital - it'll start next week. Not sure if they still have space but you can call to check. They have 6 talks in total. http://www.hksh.com/index.html
click on "產前講座班"