birth certificate, requires proof from U.S. ambassy ?

I have a question for those who have experienced this--

I need to get birth certificate from China, I am in U.S. now.

My parents went to Gong(1) An Ju(2), the answer from there is that I need to present some document from ambassy here saying that it is ME (with recent pics) who is asking my parents to get birth certificate for myself.

Although reasonable, I did not find similar situation from previous posts on this "birth certificate" topic.

I will call the ambassy anyway, but anyone has any insight on this ?

Thanks in advance!