In the late 1980s, she began to specialize in eugenics, conducting a study into test tube fertilization in Denmark.
In 1972 she gave birth to Nanna ten months later left the father who subsequently cared for her daughter.
In 1979 she married the high court judge Henrik Kristian Zahle (born 1943) with whom she gave birth to a second child, Maria.
[1] Raised in an academic, Grundtvig-inspired home, Koch attended N. Zahle's School, where she was specially interested in physics and chemistry.
There she has been a major contributor to research on eugenics, hereditary biology and fetal diagnostics, publishing widely on these and related subjects.