Could depression during pregnancy cause low cortisol levels in the baby?

No: One study shows that infants of depressed mothers actually had slightly higher cortisol levels than others, especially if the mom had anxiety also: http://tinyurl.Com/k5cgwfo these changes no longer existed at 18 mo, perhaps when the infants' self-regulatory abilities kick in. Maternal depression can have other effects on infant development, though: http://tinyurl.Com/ltlfasx.