Life begins at fertilization, or conception. This is a biological fact. Open a human embryology textbook and the definition is clearly stated. As a practicing physician I understand this biological truth.
Being pro-life does not mean that one is anti-woman. Women should have absolute bodily autonomy at the age of majority provided that those choices do not adversely affect the intrinsic right to life of another – namely their unborn child.
Being pro-life simply means that once a life has begun it cannot be ended unless there is a compelling reason to do so. The only compelling reason to do so would be the exceedingly rare scenario of imminent threat to the life of the mother. These situations are exceedingly rare as most threats to the mother can be addressed by early delivery of the baby.
As Thomas Jefferson wrote in our Declaration of Independence, human persons are “endowed by their Creator with inalienable rights, and that among these are life, liberty and the pursuit of happiness.” Life is the first right given to us by God and makes all other rights possible.