Nutrients and Postpartum Mental Health

While the effectiveness of omega-3 fatty acids in major depressive disorder (MDD) has been established, Zhang et al. (2020) point out the lack of data on the safety and efficacy of its mono-therapeutic use in perinatal depression (depression in new mothers following birth of newborn). This meta-analysis included 8 randomized placebo-controlled trials (totaling 638 participants) that analyzed the efficacy and safety of omega-3 fatty acid monotherapy in perinatal women with depressive symptoms. There is reason to believe that omega-3 fatty acids significantly affect perinatal depression, particularly when considering omega-3 with a higher ratio of EPA/DHA (≥1.5) in both mild-to-moderate antenatal and postpartum depression. Safety was not found to be an issue, with low occurrence rates and no significant difference in prevalence of gastrointestinal and neurologic problems between the omega-3 and placebo groups. Moreover, there was no evidence of publication bias. This meta-analysis suggests that omega-3 fatty acids significantly enhance depressive symptoms in perinatal women regardless of timing (during pregnancy or following birth) and are well tolerated. Another notable point was that this omega-3 response was linked to higher EPA ratio in omega-3 formula and mild-to-moderate depression.

While adolescent pregnant women are more likely to be deficient in nutrients, and feel stress and depression compared to pregnant adults, Singh et al. (2017) believe that this may correlate with poorer pregnancy outcomes too. The purpose of this study was to examine 108 pregnant Latina adolescents, evaluating the relationship between their micronutrient dietary intake, stress, and depression. The 24-hour dietary recall administered during the 2nd trimester of pregnancy revealed a high percentage of adolescents (>50%) consumed inadequate levels (excluding dietary supplements) of folate, vitamin A, vitamin E, iron, zinc, calcium, magnesium, and phosphorus. Moreover, at least 20% of the subjects had not obtained enough thiamin, riboflavin, niacin, vitamin B6, vitamin B12, vitamin C, copper, and selenium. When the micronutrient intake from prenatal supplements was included, dietary intake for most micronutrients improved but concentrations of calcium, magnesium, copper, selenium, and phosphorus were still below the Estimated Average Requirement. More depressive symptoms were related to higher consumption of energy, carbohydrates, and fats, as well as low intake of magnesium, while greater social support satisfaction was positively associated with dietary intake of thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, vitamin C, vitamin E, iron, and zinc. These findings indicate that mood and dietary factors are interrelated, and should be considered during adolescent pregnancy.

Sparling et al. (2017) speculate that women may be at risk of developing depression particularly during the perinatal period (immediately after childbirth) because of the depletion of nutrients caused by pregnancy and lactation. This review summarized the evidence on whether the nutrient levels of women in the perinatal period influence the risk of developing depression. Twenty-four articles were included, representing a total population of 14,262 subjects. Fourteen studies indicated correlations between lower levels of folate, vitamin D, iron, selenium, zinc, fats, and fatty acids with perinatal depression. According to two studies, perinatal depression was associated with higher concentrations of nutrients, while 8 studies did not identify any interrelation. Although low risk of bias was reported by 10 studies, the causal relationship between nutritional biomarkers and perinatal depression cannot be confirmed considering the limitations in methodology and heterogeneity of these studies’ approaches and results. Additional research is required.

This 2018 review examined the evidence on the link between vitamin D levels with antenatal depression (AD) and postpartum depression (PPD) since findings on these associations have been inconsistent. While a total of 239 relevant studies were identified, the two independent authors selected 14 to be included in this review. The quality of the included studies ranged from moderate to high. Of the 9 studies on postpartum depression, 5 (55%) demonstrated a strong correlation between vitamin D and postpartum depression. While five out of seven studies on antenatal depression indicated a significant association with vitamin D status. However, the data could not be transformed to measure one single effect due to the various effect estimates and statistical analyses used by the studies, and it was not possible to implement the meta-analytic techniques. Nevertheless, Aghajafari et al. declare that vitamin D status is significantly linked with antenatal and postpartum depression.

This 2019 review examined the link between anemia and/or iron deficiency with postpartum depression (depression during the period immediately after childbirth). Iron deficiency and anemia are common in women during pregnancy and postpartum due to blood loss and increase in demand. But many women may also enter pregnancy with low iron stores. After identifying and analyzing 17 studies (randomized-controlled trials and observational studies) that assessed the impact of anemia, iron-deficiency, and iron supplementation on the risk of postpartum depression, Wassef et al. discovered that most studies (8 out of 10) observed higher prevalence of postpartum depression in anemic women. Low levels of ferritin (blood protein that contains iron) in the postpartum period, but not during pregnancy, was associated with elevated risk of postpartum depression. This risk was reduced by supplementing with iron during the postpartum period (indicated by 4 out of 5 studies) but administration during pregnancy did not provide protection from depression. While additional studies should hopefully confirm this association, it is deduced that anaemia and/or iron deficiency may contribute to postpartum depression in at-risk women.

In this review, Sparling et al. (2017) aimed to evaluate whether perinatal depression (depression during pregnancy or post‐partum) is connected to dietary intake (adherence to diets, dietary consumption of essential nutrients or supplements). This association has been proposed since essential nutrients that are important in the neurotransmission system are depleted during pregnancy. Of the 35 articles that met the inclusion criteria, 6 were randomized controlled trials, 12 were cohorts, 16 were cross-sectional studies, and 1 was case-control. Studies were also divided into 4 main categories based on dietary intake: adherence to dietary patterns (9 studies); full panel of essential nutrients (6 studies); specific nutrients (8 studies); and intake of fish or polyunsaturated fatty acids (12 studies). While 13 studies did not demonstrate a link, the protective roles of healthy dietary patterns, multivitamin supplementation, fish and PUFA intake, calcium, Vitamin D, and zinc were evident in 22 studies. Nevertheless, more longitudinal studies are required, along with robust and consistent assessment of dietary consumption and depressive symptoms. Due to the limitations in methodology of the studies and their inconsistent findings, it cannot be confirmed yet whether nutritional factors influence the risk of perinatal depression.

This review conducted by Hsu et al. (2018) evaluated the effect of supplementation with omega-3 polyunsaturated fatty acid on depression during pregnancy or in postpartum depression directly after childbirth. In addition to studies that measured dietary intake and plasma and/or milk levels of omega-3 fatty acids, the reviewers selected several trials demonstrating the impact of omega-3 fatty acids supplements on pregnant or postpartum women with depression. One of the risk factors of postpartum depression is omega-3 fatty acid deficiency, which becomes depleted quickly during pregnancy and lactation. Some studies reported associations between neuroinflammation (elevated proinflammatory cytokines) and aberrant neurotransmission (low serotonergic transmission activity) with risk of developing postpartum depression. There is evidence that supplementation with eicosapentaenoic acid (EPA)-rich oil can reduce depression during pregnancy as well as postpartum depression following childbirth. It was also highlighted that long-term treatment with DHA-enriched oil may be effective in reducing postpartum depression risk in healthy women but may not be as effective in lactating women. But when this oil was taken throughout pregnancy and even after childbirth, no beneficial effect was observed. To summarize, dietary supplementation with omega-3 fatty acids rich in EPA during pregnancy or postpartum reduces symptoms related to depression, while DHA supplementation reduces the risk of postpartum depression when administered to healthy pregnant women.

The aim of this 2019 study was to determine the relationship between maternal omega-3 polyunsaturated fatty acids levels during the early stages of pregnancy, and the risk of postpartum depression. Hoge et al. state that the evidence is still unclear whether omega-3 polyunsaturated fatty acids (n-3 PUFA) and their mediators can regulate biological processes involved in the development of postpartum depression despite several reports by studies. This present study recruited 72 healthy women in Belgium, analyzed their levels of erythrocyte fatty acids before assessing their postpartum depression through a phone interview one year after delivery of the baby. Analysis models revealed that higher ratios of n-6/n-3 and arachidonic acid (AA)/eicosapentaenoic acid (EPA) were significantly associated with elevated risk of developing postpartum depression. Furthermore, women with omega-3 indices of less than 5% were 5 times more likely to experience depressive episodes than women with indices ≥5%. This study found that pregnant women with low n-3 PUFA status only or in addition to high n-6 PUFA status in early pregnancy, were at greater risk of developing postpartum depression. The author therefore emphasizes that regulating maternal n-3 PUFA deficiency can be a safe and cost-effective strategy for preventing postpartum depression.

This 2020 review focuses on the health-related events associated with different levels of omega-3 fatty acids during pregnancy and discusses the target omega-3 index result for optimal outcome. Although many recommend pregnant women to take 200mg docosahexaenoic acid (DHA) supplements every day, Von Schacky argues that plasma levels of DHA don’t always correlate with the amounts consumed. Moreover, the mean omega-3 index among pregnant women in Germany (where premature birth is a major health issue) was below the target range suggested for cardiovascular disease (8–11%), although people were supplementing with EPA and DHA. But individual trials and certain meta-analyses have claimed that prevalence of premature birth and other health problems in the mother and child can be reduced by increased intake of EPA and DHA. This review also goes on to note that overconsumption and very high levels of these fatty acids (EPA and DHA) may result in health issues such as bleeding, prolonged gestation, and even premature birth. Finally, the evidence suggests that aiming for the target range for the Omega-3 Index of 8–11% might be important in pregnancy and lactation.

Since postpartum depression is the most common psychiatric condition to arise after childbirth that affects both the mother’s and child’s health, Zhao & Zhang (2020) examined the systematic reviews and meta-analyses available to determine the risk factors of postpartum depression. By scouring through the data on several databases, the researchers discovered not only risk factors but also controversial and protective factors. Controversial factors included blood cortisol levels, while the following were identified to have protective roles in postpartum depression: skin-to-skin care, higher concentrations of Docosahexaenoic acid (DHA) in the mothers’ milk, increased seafood intake, healthy dietary patterns, multivitamin supplementation, fish and PUFA intake, calcium, Vitamin D, and zinc. The risk factors of postpartum depression were mainly related to violence and abuse, immigration status, gestational diabetes, cesarean section, depressive history, vitamin D deficiency, obese and overweight, lack of social support, traditional dietary pattern (Japanese, Indian, United Kingdom, and Brazilian dietary pattern), multiple births, preterm and low-birth-weight infants, postpartum anemia, negative birth experience, and postpartum sleep disruption and poor postpartum sleep. While several risk factors were identified by this review, 5 factors were controversial due to limited evidence.