Direct abortion is never necessary to save the life of the mother. More than 900 doctors and other medical professionals have signed their names to that statement. There are times when it is medically necessary and morally justifiable to remove the child from the mother for the sake of saving the mother's life, even if this causes the death of the child. However, it is never morally justifiable to purposely seek the death of an unborn child.
People claiming that abortion must be legal to protect women's lives are making a false claim. Remember that the goal of an abortion isn't simply to end a pregnancy, but to first kill the child and then remove his dead body - usually in pieces. There is no reason that the death of the child (as opposed to merely the removal of the child from her body) would ever help the mother or be necessary for her health. Abortion that seeks the death of an unborn child is not a treatment for any disease or health problem of the mother, and we don't need legal abortion in order to give women the best medical care.
But there's more that they aren't telling you.
In a number of cases, particularly late in pregnancy, abortion is actually more dangerous to the mother than removing the baby alive. In late pregnancy (after about 20 weeks or so), the fastest and most efficient way to make a woman unpregnant is to remove the child via c-section. A c-section can be done in a matter of minutes with minimal danger to a woman's life and to the baby's.
Of course, if the baby is less than full-term, he may need extensive medical care to keep him alive. And he may die, even with the best medical care. However, a c-section offers the quickest way to remove the child from the womb and also gives the child a chance to live. In an emergency that necessitates quickly removing the child from the womb, c-section is usually the best option, even if we're only talking about the mother's health.
In contrast, an abortion in late pregnancy increases the risk to the mother. For one thing, late term abortions usually involve dilating the mother by inserting a small dilator around 24 hours before the procedure. That's 24 hours of waiting that allows the dangerous situation to continue. There is a reason that there is such a thing as an "emergency c-section" but not an "emergency abortion." A c-section is much faster.
Plus, during an abortion, it is possible for parts to be missed (leading to infection), for damage to be done to the cervix during the procedure, for the forceps or suction device to perforate the uterus, or for some of the floating baby parts to cause damage inside the uterus. When you take out an intact baby by c-section, the risk to the mother is lower. Some doctors have even argued for "after birth abortion," claiming it is safer for the mother to remove the child from the womb intact and then kill him.
Of course, abortion is never safe for the child. But it really isn't so safe for the mother either. All those late term abortions the pro-aborts keep telling you only happen in medical emergencies aren't really so justified after all.