Markhus · PloS one 2013 · prospective cohort study · n=?

Low omega-3 index in pregnancy is a possible biological risk factor for postpartum depression.

Cited 115 times in the scientific literature.

Level 3 - non-randomized controlled study

Prospective observational cohort study with exposure measured during pregnancy and outcome assessed postpartum

PubMed 23844041 · doi:10.1371/journal.pone.0067617 · record verified 2026-08-29

What was done

A community-based prospective cohort study followed pregnant women recruited between November 2009 and June 2011 in a municipality in Western Norway. Red blood cell fatty acid profiles, including the omega-3 index, were measured at the 28th week of gestation. Postpartum depression symptoms were screened 3 months after delivery using the Edinburgh Postnatal Depression Scale (EPDS).

What was found

In a simple regression model, the omega-3 index was associated with the EPDS score in a nonlinear inverse manner, explaining 19% of the variance (R² = 0.19). DPA content, DHA content, omega-3 index, omega-3/omega-6 ratio, total HUFA score, and omega-3 HUFA score were all inversely correlated with EPDS scores. Participants in the lowest omega-3 index quartile had significantly different (higher) EPDS scores compared to the other three quartiles.

Why it matters

This study provides prospective biological evidence linking low maternal omega-3 fatty acid status in late pregnancy to higher risk for postpartum depressive symptoms, highlighting a potential dietary target for maternal mental health.

Limits

The abstract does not report the participant sample size (n), confidence intervals, or exact effect estimates beyond the R² value. Findings are derived from simple regression without reported adjustment for key confounders (such as prior history of depression or socioeconomic status), and the observational design cannot establish causality.

Cited by