Reuters quoting British doctors stated that depression during pregnancy is more common and can be just as serious as postnatal depression.
Postnatal depression, a well known phenomenon that affects about ten per cent of women, has caused widespread concern following highly publicised cases of women who have harmed or killed their children.
But new research reported in the British Medical Journal showed depression was most common during the eighth month of pregnancy and least common eight months after the birth.
"Our results show depression during pregnancy is more common than postnatal depression," said Jonathan Evans, a psychiatrist at the University of Bristol in South-western England.
Evans and his team studied the mood swings of more than 9,000 women who recorded their feelings during and after pregnancy. Their symptoms were measured against a recognised depression scale.
"Symptoms of depression are not more common or severe after childbirth than during pregnancy," Evans said, adding that treatment during pregnancy might be necessary for the well being of the woman as well as the child.
Huge changes in hormone levels are blamed for the mood swings, or baby blues, that women suffer during and after pregnancy.
Anxiety and irritability are common complaints that usually pass but if they persist and lead to anger, guilt, confusion, delusions and obsessional thoughts, the problem is much more serious and professional help may be necessary.