Atheist, Agnostic and Otherwise Non-Religious Pro-Life groups:
4) Atheist and Agnostic Prolife League
7) Feminists For Life
[Not strictly secular, but very amenable to secularism].
8) Consistent Life
[Pacifist group not strictly secular, but ecumenical and amenable to secularism]
9) Democrats for Life
[Not strictly “secular” but admits and supports secular members and, compared to Republican pro-life groups it does not appear to be as religious]
10) Prolife Alliance of Gays and Lesbians
11) Seamless Garment
Sample Articles
Kathryn Reed, “Feminist, Prolife, and Atheist”
Patrick [Anonymous], “Confessions of a Prolife Atheist”
Kristine Kruszelnicki, “Yes There Are Pro-life Atheists Out There. Here’s Why I’m One of Them”
Leslie Fain [catholic reporter], “Atheist, Secular, and Prolife”
Sarah Terzo, “On Being a Prolife Atheist”
Intelligent Christian Faith 
I’m pro-life. But I’m also pro-choice.
I also love semantics. (Couldn’t resist.)
So you support Roe v. Wade and also want it abolished? I use the terms because they are conventional. But I’ve never met someone who tries to affirm both consistently, who is not also trying to justify a more fundamental abortion-choice stance. In other words, prochoice don’t want to admit that they advocate for the knowing and willful killing of their own offspring, their defenseless, innocent, living children in utero.
Another one for your list:
Pro Life Pagans
https://www.facebook.com/ProLifePagans?refid=52&_ft_=top_level_post_id.383587524995665