According to the catholic archdiocese of San Francisco:

"Top-quality Pro-Life Educational Ad Campaign on BART trains. BART’s advertising agency has approved a pair of professionally prepared ads targeting women of “pro choice” persuasion for education about the Roe vs. Wade Supreme Court decision. These visually compelling ads, entitled “Choose” and “9 months” were commissioned by the USCCB Poe-Life Secretariat, and appeared last January on the Supreme Court’s role in our nation’s abortion law. Beginning the day after Christmas, just as Roe’s January anniversary and the next round of nominee hearings begin, the ads will appear inside many BART’s cars and will stay up at least 4-weeks. Here’s where I need you help: BART has also approved In-Station Billboards, which complement out in-car ads."

Source (and more info on the ad campaign's logistics and fundraising) at:
http://www.sfyam.org/calendar/detail.asp?event_id=2187&date=12/26/2005&view=month


The entity responsible for these ads is the Second Look Project:
http://www.secondlookproject.org/


and of course, BART:
http://www.bart.gov

contact BART:
http://www.bart.gov/guide/overview/contactbart.asp?ct=1