Depression During Pregnancy: Are Omega-3 Deficiency and Inflammation Among the Causes?

Depression during pregnancy, a disorder affecting about 16% of pregnant women, is associated with low omega-3 levels in the blood and increased inflammation. In the second and third months of gestation, depressed women, compared to healthy ones, show lower concentrations of EPA and DHA and higher amounts of TNF-alpha, a signaling molecule of inflammatory status. Omega-3 deficiency is also correlated with prolonged depressive episodes, which can last even after childbirth.

This was reported in a recent study conducted by researchers from China Medical University in Taichung (Taiwan) and published in the scientific journal Progress in NeuroPsychopharmacology and Biological Psychiatry.

Prenatal depression: a common but often unrecognized disorder

Prenatal depression (PND), or depression during pregnancy, is a very common illness among women of childbearing age and represents one of the main complications during pregnancy and the major risk factor for postpartum depression. 

Prenatal depression is a psychiatric disorder affecting about 16% of women during maternity. The prevalence of depression in pregnancy is higher in the first trimester and decreases in the second and third. Only 49% of pregnant women affected by depression seek medical help, and symptoms are often underestimated by both patients and specialists, so the disorder often goes unrecognized. Depression during pregnancy can have important consequences for the future mother, the baby, and the rest of the family. 

This type of disorder can affect women of any age, origin, and social background, although among the most common risk factors are both socioeconomic ones and those related to the woman’s health and physiological conditions, including:

• very young pregnancy age
• lack of family support
• conflictual relationship with partner
• disadvantaged socioeconomic conditions
• hormonal problems
• physical or psychological disorders

The consequences of depression during pregnancy can lead the future mother to dangerous behaviors such as poor self-care, lack of appetite and malnutrition, alcohol or tobacco abuse, inability to recognize labor signs. Furthermore, as already mentioned, prenatal depression can predispose to postpartum depression, which is a major cause of psychosocial dysfunctions, suicides, and adverse neonatal care. Several studies over the years have demonstrated the importance of a healthy diet and proper intake of vitamins and omega-3 for the health of mothers and babies, and have suggested a link between EPA and DHA deficiency and an increased risk of depression both before and after childbirth. 

Depression during pregnancy is more frequent when omega-3 is deficient  

The Taiwanese researchers measured omega-3 levels and inflammatory markers, such as tumor necrosis factor alpha (TNF-alpha), in women with PND and those without depression during the second and third trimesters. The results showed that expectant mothers with depressive disorder had significantly lower omega-3 levels and higher TNF-alpha levels compared to healthy women. These data align with other studies indicating that high DHA and EPA levels in the blood act as protective factors against major depressive disorder. Additionally, higher DHA concentration in breast milk and greater consumption of DHA-rich fish have been associated with lower prevalence of postpartum depression. Both DHA and EPA have also been effective in preventing and treating depressive disorders. 

Omega-3 fatty acids are essential for fetal development, playing an important role in cellular and physiological function during the perinatal period, i.e., from pregnancy to 12 months after birth. During this time, increased demand for EPA and DHA may increase the risk of PND in pregnant women, especially since the physiological and psychological stress caused by pregnancy could trigger the release of inflammatory substances, such as pro-inflammatory cytokines and TNF-alpha, which may represent a biological indicator or even a precursor of depression during pregnancy. 

Study details 

The study involved 33 women; 16 healthy and 17 with PND. Blood samples were taken and analyzed from each participant. Cases of depression were diagnosed using a specific diagnostic manual of mental disorders. Data were then correlated using statistical analyses, showing that depressive syndrome is significantly associated with lower levels of DHA, EPA, total omega-3, and a high ratio between omega-6 and omega-3. The duration of PND was associated with lower DHA and EPA levels, the omega-6 to omega-3 ratio, and TNF-alpha concentration. Omega-3s are essential to combat neuroinflammation. According to the researchers, it is possible to hypothesize that sufficient omega-3 levels are needed to combat neuroinflammation and produce an antidepressant effect in pregnant women. As is known, these fatty acids are components of neuronal membranes and are involved in the proper functioning of neurotransmitter transmission related to mood regulation. Further future studies with larger samples will be needed to replicate results and clarify the role of the inflammatory mechanism in patients with depression during pregnancy. 

Source: Jane Pei-Chen Chang et al., “Polyunsaturated fatty acids and inflammatory markers in major depressive episodes during pregnancy” Progress in Neuro-Psychopharmacology and Biological Psychiatry.