I am always surprised when I read a post such as yours. I don’t believe you personally have to contribute to someone else’s (R”L) painful, uncomfortable, frustrating, and often disappointing fertility treatments, so that they may be makeyim the mitzvah of pru urvu, but do you REALLY want to suggest that it is not an act of chessed to have an organization help raise funds to help someone else in this sad situation? If you feel this is not a worthy tzedaka (as with ANY tzedaka towards which you feel negativity), then by all means do not contribute. I have five children bli ayin hara (with no difficulty conceiving them, B”H), and I am very privileged to take up the slack for your share of the tzedaka.
May Hashem protect you and all your family members from ever knowing such tzaar as the inability to have children.