Definitions for "Baby blues"
Mild depression that follows childbirth. It is usually the result of the postpartum  hormonal swings and the natural slump after the excitement of labor and birth. Baby blues affects 60 to 80 percent of all new mothers. See postpartum depression.
A period of mild depression after childbirth, the baby blues tends to last a few hours or a few days and then disappears. Not to be confused with postnatal depression (see definition).
The "baby blues" is a mild depression which many women experience three or four days after giving birth. Weepiness, mood swings, anxiety and/or unhappiness can result from the dramatic drop in hormones after birth and from a feeling of anticlimax after the anticipation and excitement of having a baby. See also postnatal depression.