Dysthymia is a mood disorder characterized by chronic mildly depressed or irritable mood often accompanied by other symptoms such as eating and sleeping disturbances, fatigue and poor self-esteem. A study of 72 mothers with prenatal depression compared those with dysthymia to those with major depression. Previous studies have found that while women with major prenatal depression feel worse women with dysthymia had higher prenatal cortisol (a substance associated with stress) levels and smaller children. The study, by researchers in the U.S. found that the children of dysthymic mothers had a shorter gestational age, a lower birthweight, more obstetric complications and lower orientation and motor scores than the children of mothers with major depression.
Field, Tiffany, Diego, Miguel and Hernandez-Reif, Maria - Prenatal dysthymia versus major depression effects on the neonate Infant Behavior and Development April 2008, 31(2), 190-193