This seems to go beyond advocating for the legality of this care and extend to demanding that medical professionals be compelled to provide it.
I don't think a high risk of bith defects should require sterilization before pain treatment, but at some level of risk a tubal ligation could be the right thing to do. And beyond that, what is a doctor's liability if their actions cause a birth defect? Is their decision here partly self defense? Would a truly legally binding release from liability free them to help?
I empathize with this woman's pain and hope she gets treatment quickly. But this is a particularly ethically complex situation with no obvious villains.