Participant’s response to the electronic questionnaire in pregnancy.

<p>Bar chart presenting the median EPDS score measured 3 months postpartum of non-responders (n = 8) and responders (n = 36) to an electronic questionnaire (seafood intake, demography, socioeconomically status, psychological status) in pregnancy. * Significantly difference at the 0.001 level. † 28th week gestation. ‡ Edinburgh postnatal depression scale.</p

Association between the omega-3 index and absolute DHA and EPA in red blood cells.

<p>Scatter plot of the omega-3 index and the corresponding DHA content (µg/g) and EPA content (µg/g) in red blood cells, and the respective fitted regression lines. The omega-3 index is the content of EPA+DHA in red blood cells membranes expressed as a percent of total fatty acids.</p

Socio-economical and behavioural characteristics of study participants (n = 55).

†<p>University or university college.</p>‡<p>n = 53 (2 participants with missing data).</p>§<p>100 000 NOK ≈ 14 000 EUR.</p>∥<p>n = 54 (1 participant missing data).</p

Association between the omega-3 index in pregnancy and postpartum depression.

<p>Scatter plot of the non-linear relationship between the marine omega-3 status (omega-3 index) in pregnancy and postpartum depression score (EPDS). A rectangular hyperbolic equation (<i>y</i> = -1.31+28.1/x) was the best fit for describing this relationship (<i>ß</i> = 0.43, <i>F</i> (1,41) = 9.32, <i>p</i><0.004, n = 43). The vertical lines represent omega-3 index quartiles. Red markers represent individuals in the 25 percentile. † The content of EPA+DHA in red blood cells membranes expressed as a percent of total fatty acids ‡ Edinburgh postnatal depression scale.</p

Flow chart of the study design.

<p>* Of which one respondent did not provide a blood sample ** Of which 54 responders and 15 non-responders to the electronic questionnaire *** Of which 35 responders and 8 non-responders to the electronic questionnaire. 26 participants were not screened for depression 3 months postpartum due to drop out or losses to follow up.</p

Seafood consumption and prevalence rates of postpartum depression.

<p>Postpartum prevalence rates for Australia, New Zealand, Sweden and the United Kingdom, The United States were derived by meta-analysis. All other countries are represented by a single study, see text. Apparent Seafood consumption lb/person/year is an economic measure of disappearance of all fish and seafood from the economy and is calculated by imports plus catch minus exports. A logarithmic regression was used for analysis (<i>r</i> = −0.81, <i>p</i><0.001). In Norway the seafood consumption is (47 lbs/person/year = 21,3 kg/person/year <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067617#pone.0067617-Helsedirektoratet1" target="_blank">[94]</a> and the prevalence of postpartum depression is 10% <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067617#pone.0067617-Berle1" target="_blank">[3]</a>. Modified from Hibbeln <i>et al. </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067617#pone.0067617-Hibbeln2" target="_blank">[30]</a>.</p

Spearman’s correlation coefficients (<i>r_s</i>) between background variables/other potential risk factors for PPD^† measured in pregnancy, and the omega-3 index^‡ in pregnancy, and EPDS^§ score postpartum (n = 35).

*<p>Significant at <i>p</i><0.01.</p>†<p>Postpartum depression.</p>‡<p>The content of EPA+DHA in red blood cell membranes expressed as a percent of total fatty acids.</p>§<p>Edinburgh postpartum depression scale.</p>∥<p>n = 33 (two participants with no partner).</p

Fatty acid profile of the study population, and Pearson’s correlation coefficients between the fatty acids in red blood cells, expressed as relative amount, and the EPDS^‡ score (n = 43).

†<p>Measured fatty acid value below the limit of quantification for the method.</p>‡<p>Edinburgh postpartum depression scale.</p>§<p>Correlation between % of total fatty acid and EPDS.</p>∥<p>The content of EPA+DHA in red blood cells membranes expressed as a percent of total fatty acid.</p>¶<p>Total HUFA is the sum of the omega-3 and the omega-6 HUFAs, and the red blood cells omega-3 HUFA score equals 100% - omega-6 HUFA.</p

Descriptive, socio-economic and behavioral characteristics of study participants (T1 n = 55, T2 n = 92, T3 = 82 and T4 = 78).

<p>* An independent sample t-test was applied to normal data (age) and Man-Whitney for non-normal data (BMI, education, employment, marital status, own income and breastfeeding)</p><p>¹ Age and BMI are presented as mean ± SD</p><p>² BMI pre-pregnancy</p><p>³ University or University College</p><p>⁴ Data not requested at time point 3 and 4 (no new recruitment)</p><p>⁵ 100 000 NOK ≈ 14 000 EUR</p><p>Descriptive, socio-economic and behavioral characteristics of study participants (T1 n = 55, T2 n = 92, T3 = 82 and T4 = 78).</p

Flow chart of study- population and design.

<p>¹ Not all women from the source population were asked to participate in the study while still pregnant, partly for practical reasons and partly due to exclusion criteria (unable to understand Norwegian). ² 2 BS and 16 FFQ missing at random or passive dropout. ³ Women recruited 2–6 weeks postpartum to restrict selection bias as not the whole source population was asked to participate during pregnancy due to practical reasons. ⁴ Passive drop-out sometime between T1 and T2. ⁵ 18 BS and 16 FFQ missing at random or passive drop-out. ⁶ 21 BS and 21 FFQ missing at random or passive drop-out. ⁷ 30 BS and 26 FFQ missing at random or passive drop-out. BS: blood sample; FFQ: food frequency questionnaire.</p