I've worked 17 years as a full-time pro-life apologists and I've seen both Christian and non-Christian pregnancy centers save lives.
My concern is not that some centers do evangelism, but where they place that objective in evaluating their work. For example, I once spoke at a fundraiser for a CPC (I do about 25 of these banquets each year) where the board chairman opened the evening with this statement: "We are not here to stop abortion. We are here to present the Gospel to women."
That's fine, but if a CPCs primary mission is evangelism, it should become a church or evangelistic organization with a pro-life statement of faith.
But if its stated goal is to reach abortion-minded women in hopes of dissuading them from abortion (which is what CPCs were originally designed to do in the first place), success or failure is not based on how well we share the gospel, but how many lives we save given the resources at our disposal.
Make no mistake: I'm not saying it's an either/or proposition--that is, save lives or do evangelism. It can be both, depending on the stated mission of the center.
But we shouldn't conclude that 1) all centers must do evangelism to effectively save lives, or 2) evangelism should become our primary focus.
Bottom line: If a CPC is doing a great job at evangelism but not a great job saving lives, it needs to rethink its primary mission.