Maternity blues
Maternity blues, also known as baby blues and postpartum blues, is a transient condition that 75-80% of mothers could experience shortly after childbirth with a wide variety of symptoms which generally involve mood lability, tearfulness, and some mild anxiety and depressive symptoms. Baby blues is not postpartum depression, unless it is abnormally severe.After the placenta is delivered, the placental "hormone factory" shuts down causing radical changes in hormone levels, and the woman can suffer symptoms due to withdrawal from the high pregnancy levels of estrogen, progesterone and endorphins. Combined with this shift in hormone levels is the physical, mental and emotional exhaustion - as well as sleep deprivation typical of parenting a newborn. All of these factors contribute to the condition.
Intrusive thought
Unwanted thoughts by mothers about harming infants are common in postpartum depression. A 1999 study of 65 women with postpartum major depression by Katherine Wisner "et al." found the most frequent aggressive thought for women with postpartum depression was causing harm to their newborn infants. A study of 85 new parents found that 89% experienced intrusive images, for example, of the baby suffocating, having an accident, being harmed, or being kidnapped.