The mother has a right to her body, but a baby is not her body.
If the mother has a baby boy and the doctor identifies the fetus in the womb as such you wouldn't say the mother is both male and female at that point.
Sex is applied to each person, which would seem to make the case that people implicitly accept that fact when they continue to call the mother a 'her' and not a 'he she' when pregnant with a male.
"Anarchism is not a romantic fable but the hardheaded realization, based on five thousand years of experience, that we cannot entrust the management of our lives to kings, priests, politicians, generals, and county commissioners."