Our main problem in the world today is how much resources humans use. Reducing the number of children in rich countries is much more efficient than reducing the number in poorer countries. Luckily, most rich countries are solving this on their own, with negative birth rates in countries such as Japan and Germany. My main reason to oppose a focus on limiting population growth, is that I have never seen the argument contributing constructively to any discussion. The times I have seen it used IRL, it has either been a cover for racism, or as an excuse for doing less to reduce their own environmental impact.
With all debates that really are about traditions, values and feelings, there is no use in arguing pro or contra directly. There have never been as many people taking part in whaling in the Faroes, as in the years after Sea Shepherd ran their large campaigns against "the grind". "Pro life" and "pro choice" are landmines. If we all focused on the measures that really reduced abortions, we could make make big changes: high quality sex education, free contraceptives, anti rape measures that focus on teaching men not to rape, excellent financial and social support for mothers, free daycare, etc.
In addition to free contraceptives, if we really want to reduce reproduction rates, education and employment for women is alpha omega. (And light bulbs. There is a very clear negative correlation between number of light bulbs in a country, and the number of children per woman.)