“If it was on planet Mars, it would be life, but the fact that it's here on a mother’s belly and not classified as life is astonishing to me,” he said.

One supporter said death is measured by the end of a person’s heartbeat, so life should be measured by the beat’s beginning.

Dr. Erin King, executive director of the Hope Clinic for Women in Illinois, called the proposal “an extreme and dangerous measure” that comes close to banning all abortion in Missouri. The obstetrician gynecologist explained the change would ban abortion before most women even realize they’re pregnant.

“If House Bill 126 were enacted, it would no longer matter what this patient wanted, her life circumstances or what could be best for her medically,” King said.

Rep. Sarah Unsicker, D-Shrewsbury, noted the legislation's cost estimate, which indicates that Missouri could lose more than $7 billion in Medicaid funding because of a potential conflict with federally mandated abortion requirements in cases of rape, incest and when the procedure is needed to save mothers' lives.

Schroer said both Republicans and Democrats have criticized fiscal analyses conducted by taxpayer-paid, nonpartisan legislative staff.