Many women feel depressed after pregnancy called post-partum depression or "baby blues". New research says that low levels of omega-3 fatty acids may be a reason for this depression.

"The literature shows that there could be a link between pregnancy, omega-3 and the chemical reaction that enables serotonin, a mood regulator, to be released into our brains. Many women could bring their omega-3 intake to recommended levels," said Gabriel Shapiro of the University of Montreal and the Research Centre at the Sainte-Justine Mother and Child Hospital.

Researchers say that omega-3 is transferred from mother to growing fetus during pregnancy and even later through breast milk meaning that the mother is left with very little of this fatty acid. Additionally, many women don't even take the required amount of omega 3 in their daily diets.

"These findings suggest that new screening strategies and prevention practices may be useful," Shapiro said.

In the U.S., the main sources of omega-3 fatty acids are vegetable oils, particularly canola and soybean oils, fatty fish, such as salmon, mackerel, herring, sardines, and tuna, says National Center for Complementary and Alternative Medicine. Women who are pregnant or breastfeeding are advised to consume at least 8 ounces but no more than 12 ounces of seafood each week and not eat certain types of fish that are high in mercury. Fish high in mercury can harm the nervous system of a fetus or young child, according to The Dietary Guidelines for Americans.

Shapiro added that the present study was a preliminary one and more studies are required to find out a link between omega 3 and pregnancy related depression.

The risk of postpartum depression is higher for women who are under the age of 20, abuse alcohol, had an unplanned pregnancy, have previous history of depression or bipolar disorder, are single or in a stressful relationship, have low income, according to Medline Plus.

Postpartum depression can kick in anywhere between a few months to a year after the woman has given birth. However, many women experience depression after about three months post-delivery.

About 14 to 23 percent of women will have some symptoms of depression even during pregnancy, a report from The American Psychiatric Association and The American Congress of Obstetricians and Gynecologists (ACOG) said.

The findings were announced by the Canadian Journal of Psychiatry.