Do adoption agencies only adopt out to couples who can't have kids of thier own?

My husband and I have no issues with infertility or anything, but with my first pregnancy, I had preeclampsia, low amniotic fluid, intrauterine growth restriction AND partial placental abpruption...resulting in our 3 month premature daughter who only weighed 1 lb 3.4 oz at birth so we are both uncertain of the risks if we were to have another baby, so adoption is something we have considered.