There is a useful analysis of the relationship between second trimester abortions and health care funding over at the economics blog, Dollars and Sex.
From “The Economics of Second Trimester Abortions: Market Demand” by Marina Adshade: “Among women who both had second trimester abortions, and would have preferred to have one earlier in the pregnancy, 36% said the delay was caused by a need to raise the enough money to pay for the procedure. The U.S. isn’t the only nation that makes women pay for abortions, but it is the only one, that I know of, in which abortions for low-income women go unsubsidized by governments.”
Dollars and Sex, by the way, is an excellent resource for feminist philosophers. The blog covers economic aspects of dating and marriage, promiscuity, infidelity, risky sexual behavior, the relation between sex and happiness, and markets for sex such as prostitution, pornography, and lap dancing.