Abortion is just not recommended... especially when the fetus is healthy and the mother is not physically deteriorating from the pregnancy. Some people view the fetus as a lump of cells... yeah we all learnt science, and mitosis... during the first trimester, the embryo is but a size of a grain of rice, with barely enough cells to differentiate into different organ systems... in short, it barely represents a human, and if we were to take a human embryo at the first trimester to compare it with a pig's embryo, there would be no difference (sad to say...)
But in our believe, we also learnt that from the moment the ovum and sperm, it is here where the first drop of blood of a new being is formed... the primordial blood. It is here, where our consciousness enters and begins of a new life in samsara. And because our consciousness enters here, I have always wondered why people argue about abortion and easily forget about the use of 'morning after pills'... after all, the fertilisation always takes place first, then it attaches to the womb, and by taking the morning after pill it causes the womb to mature to a stage that is unfit for embryo attachment.
So, is morning after pill okay to be taken by Buddhists as it deny the attachment of the embryo to the womb? Isn't it like denying a person hungry person into your house? At least that's how I think of it.
Pregnancy that brings no harm to the mother is most advisable to continue... although like what you've pointed out, the woman may feel extreme hatred towards the child... however, there is always options to put the child into foster care. Death is so certain, but with life, there is hope of a good life.
If the woman has to hate the child, then let it be hate rather than killing... to suffer such fate, it is best to not commit more negative karma by committing a heinous deed...