It has been estimated that at a cost of about $1.7 billion a year, modern contraceptive use prevents 105 million induced abortions and another 3.6 million infant and mother deaths (in 2004) per year, with the United Nations Population Fund (UNFPA) being a main provider of contraceptives in developing countries where access would otherwise be limited. If you believe that life begins at conception, than the UNFPA has almost certainly prevented more deaths than any other organization on earth, and with more efficiency (between $7 and $177 per death prevented) than any other organization as well. The tragic irony is that funding cuts to the program in this decade have largely been driven by pro-life organizations, the very ones that hold this view of life (due to misconceptions that the UNFPA advocates abortion, which continues). This isn’t intended to be a slant against the well-meaning intentions of these organizations, but a lesson that to honestly pursue a cause, we must humbly learn from empirical feedback what are effective solutions rather than simply pushing forward with our ideological assumptions.
You can give to UNFPA here.