Health insurance reform in Massachusetts lowered the financial cost of both pregnancy (by increased coverage of pregnancy-related medical events) and pregnancy prevention (by increasing access to reliable contraception and family planning). We examine fertility responses for women of childbearing age in Massachusetts and, on net, find no effect from increasing health insurance coverage. This finding, however, masks substantial heterogeneity. For married women aged 20 to 34 – who have high latent fertility and for whom pregnancies are typically wanted – fertility increased by approximately 1 percent. For unmarried women in the same age range – for whom pregnancies are typically unwanted – fertility declined by 9 percent. Fertility rates changed very little for other groups, in part because of low latent fertility or minimal gains in insurance coverage. Pregnancy wantedness increased in the aggregate through a combination of increasing wanted births and decreasing unwanted births.