From Cortisol to Cortisone

Stress can have a variety of physiological effects on the body.

During pregnancy, excessive stress can adversely affect fetal development, and thus it is important for the mother to remain calm.
Cortisol is particularly important for mediating the effects of maternal stress, and the placenta acts a barrier to limit fetal cortisol exposure.

The placenta does this through the action of the enzyme 11-β hydroxysteroid dehydrogenase type 2 (11-βHSD2) which converts active cortisol to inactive cortisone
However, increased maternal stress has been shown to reduce placental 11-βHSD2 expression and increase fetal cortisol exposure.

See if you can use placental 11-βHSD2 to protect the fetus from maternal cortisol and keep the ratio of cortisol:cortisone below 1:10