I see where you’re coming from, but I can’t help but wonder if a more cheerful approach isn’t also possible and perhaps even more conducive to impact. Julia Wise’s thoughts in http://www.givinggladly.com/2013/06/cheerfully.html and also especially Nate Soares’ https://mindingourway.com/detach-the-grim-o-meter/ would perhaps go in that direction. Basically: Being grim kind of sucks long-term. And maybe being more positive will lead to more impact.
But without further empirical data this is just speculation on my part :P
(Just as a couple of thoughts that are better than my n=1: In community building the recommendation is opportunity, rather than obligation, framing, so it probably works better? I recall there also being some studies on advertisements with negative/positive/humorous tone, and the latter two had better effects. Probably low external validity though. Also, though, comedians like John Oliver probably have a much higher reach compared to the usual by just being, well, entertaining and fun.)
If I recall correctly, the number of worldwide abortions currently is higher than the number of deaths (from all other causes) at around 73 million vs 62 million a year. Obviously this is due to demographics and will probably change in the future, but I do think it lends credence that the scope of the problem could be (assuming abortion is wrong) ginormous. Besides questions about whether it’s right or wrong, though, I’m personally unsure that it’s neglected or tractable.
The only thing I could imagine saving it on that front is some completely different approach, like GFI has for animals. I couldn’t imagine what that looks like, though. Maybe contraceptives really is the only way? Otherwise, perhaps reducing the costs of taking a child to term, but that then sounds a lot less tractable/neglected. Presumably most anti-abortion funding is also concentrated in wealthier areas.