haha i can give you some help~~
To be honest, there are very few female doctors (i mean at least consultant level) in O&G department in NUH. Because you want to fix a doctor from the beginning which means you need to pay under "private" category, the doctor will be at least consultant.
Forget about male doctors and female non-Chinese doctors. There are two female Chinese consultants, Dr Su Lin Lin and Dr (Prof) Mary Raff. Personally I know Dr Su very well and I suggest you can go and see her. She speaks fluent Chinese and is a very easy-going person. I have two friends who approached Dr Su as their consultant as well. Prof Raff is more senior and experienced, but she does not speak Chinese at all. She is a very reputable doctor.
Hope you will find the info helpful.