To the OP:

It predominant in Asian countries because the cultural value placed on having males. In India, it is particularly prevalent amongst middleclass families, because they can afford scans to tell the parents the sex of the child. The same is probably true in China, but India has been more studied. The evidence is obvious in the distortion in the gender balance. It should be 51% male 49% female but amongst middling families in some districts it is as high at 70% male. Some refer to it as gendercide and estimate losses of up to 50 million female fetuses in Asia.

Here are a couple of articles:

http://www.gendercide.org/case_infanticide.html

http://www.dailymail.co.uk/news/article-393896/Genocide-Indias-daughters...

Here is an advocacy/campaigning group's site:

http://50millionmissing.wordpress.com/

The real issue here is not pro-choice; it is about culture preference for males and the need for these cultures to embrace the idea of women's equality.