Marjorie G. Horning

Marjorie Janice Groothuis Horning (August 23, 1917 – June 11, 2020) was an American biochemist and pharmacologist. 
She was thought to be a leading scientist of chromatography for her work in developing new techniques and applying them to the study of drug metabolism. 
She discovered that drugs and their metabolites can be transferred from a pregnant woman to her developing child, and later through breast milk, from a mother to a baby. 
Horning's work made possible the prevention of birth defects, as doctors began to warn of the dangers of drugs, alcohol, and smoking during pregnancy.