Gestational age and maternal status of DHA and other polyunsaturated fatty acids in pregnancy: A systematic review

Maternal supplementation with docosahexaenoic acid does not cause constriction of fetal ductus arteriosus: randomized controlled trial

OBJECTIVE

Docosahexaenoic acid (DHA) is recommended routinely in pregnancy to promote fetal development. DHA has anti-inflammatory activity, but its effects on the fetal heart and circulation are unknown. This study aimed to investigate whether maternal DHA supplementation in the third trimester affects maternal prostaglandin levels and fetal ductus arteriosus flow dynamics.

METHODS

This was a double-blind randomized controlled trial with parallel groups conducted between 2018 and 2021. Pregnant women aged over 18 years with a normal fetus at 27-28 weeks' gestation showing no cardiac/extracardiac anomalies or ductal constriction were eligible for the trial. Women consuming substances with a known inhibitory effect on prostaglandin metabolism, such as non-steroidal anti-inflammatory drugs and polyphenol-rich foods, were excluded. The intervention group received oral supplementation of omega-3 with 450 mg/day of DHA for 8 weeks and the placebo group received capsules of soy lecithin for 8 weeks. Anthropometric measurements, assessment of polyphenol and omega-3 consumption, fetal morphological ultrasound examination, fetal Doppler echocardiographic examination and blood sample collection were performed at the start of the study and the latter two were repeated at follow-up. Prostaglandin E2 (PGE2) level and echocardiographic parameters were compared between the intervention and placebo groups and between baseline and follow-up.

RESULTS

A total of 24 participants were included in each group. After 8 weeks, there were no significant differences between the intervention and placebo groups in maternal serum PGE2 level or Doppler echocardiographic parameters of ductal flow. No case of ductus arteriosus constriction was observed. The expected intragroup changes in cardiac morphology, as a result of advancing gestation, were present.

CONCLUSIONS

Maternal DHA supplementation in the third trimester at a clinically recommended dose did not result in inhibition of PGE2 or constriction of the ductus arteriosus. These findings should be confirmed in postmarket surveillance studies with larger patient numbers in order to test the full safety profile of DHA and provide robust clinical reassurance. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Association of serum docosahexaenoic acid and eicosapentaenoic acid levels with dietary intakes and supplement use during pregnancy: a prospective observational study

This study aimed to determine the association of serum docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) levels with dietary intakes and supplement use during pregnancy. This prospective observational study was conducted at a university hospital in Tokyo, Japan. Participants in their second and third trimesters were given a self-administered questionnaire assessing the frequency of DHA and EPA supplement use in the past month and a brief-type self-administered diet history questionnaire. Non-fasting serum DHA and EPA levels were analysed using gas chromatography. Differences in biomarkers by frequency of supplement use were determined using multiple comparison analyses, and Spearman's correlation coefficient was used to determine biomarkers and DHA and EPA intakes by food group. Of the 116 participants, 11 (9⋅5 %) in the second trimester and 18 (15⋅5 %) in the third trimester regularly used supplements (≥5 times per week). Regular users had higher serum DHA and EPA levels than never users in the second and third trimesters. Dietary DHA and EPA intake from fish and shellfish was positively correlated with serum DHA and EPA in the second and third trimesters. Supplement use ≥5 times per week and fish and shellfish intake were associated with high serum DHA and EPA levels.

Docosahexaenoic Acid Supplementation in Lactating Women Increases Breast Milk and Erythrocyte Membrane Docosahexaenoic Acid Concentrations and Alters Infant n-6:n-3 Fatty Acid Ratio

Background

Low concentrations of docosahexaenoic acid (DHA) or high n-6 (ω-6):n-3 ratio in pregnant women is associated with poor fetal growth velocity and suboptimal neurodevelopment. However, there is a lack of data on levels of important n-6 and n-3 fatty acids (FAs) at different time points during pregnancy and lactation from India. Data on how much DHA is transferred during actual supplementation are also scarce.

Objectives

We report the concentrations of n-6 and n-3 FAs in maternal and infant blood and in breast milk following maternal supplementation with DHA or placebo.

Methods

A total of 957 pregnant women (≤20 wk) from Belagavi, Karnataka, were randomly assigned to receive either 400 mg/d of algal DHA or placebo through 6 mo postpartum. Blood samples were collected from the mother at recruitment/baseline, delivery, and 6 mo postpartum and from the infant at birth (cord) and 12 mo (venous). Breast milk samples were collected from a subsample at delivery, 1 mo and 6 mo postpartum. The FA profile was analyzed using gas chromatography.

Results

The concentration of DHA appeared to be higher in erythrocyte and breast milk samples of the DHA-supplemented group at all subsequent time points. The n-6:n-3 ratio was lower among women in the DHA group at delivery [DHA: 4.08 (1.79); placebo: 5.84 (3.57); P < 0.001] and at 6 mo postpartum [DHA: 5.34 (2.64); placebo: 7.69 (2.9); P < 0.001]. Infants of DHA-supplemented mothers also had a lower n-6:n-3 ratio at delivery and 12 mo. The n-6:n-3 ratio of breast milk increased from delivery through 1 to 6 mo but remained lower in the DHA-supplemented group than in the placebo.

Conclusions

Maternal DHA supplementation with 400 mg/d from early pregnancy through 6 mo postpartum significantly increased circulating DHA in breast milk and infant erythrocyte, whereas decreased erythrocyte and breast milk n-6:n-3 ratio. However, maternal supplementation did not get the ratio to the recommended levels.

Identifying women who may benefit from higher dose omega-3 supplementation during pregnancy to reduce their risk of prematurity: exploratory analyses from the ORIP trial

OBJECTIVES

The risk factors for prematurity are multifactorial and include low omega-3 status. Omega-3 supplementation in pregnancy has been found to reduce prematurity risk, particularly among women with low omega-3 levels. This study aimed to identify maternal characteristics that predict whether women with a singleton pregnancy will benefit from omega-3 supplementation to reduce their risk of prematurity.

DESIGN

Exploratory analyses of a multicentre, double-blind randomised trial.

SETTING

6 tertiary care centres in four states in Australia.

PARTICIPANTS

5328 singleton pregnancies in 5305 women recruited before 20 weeks of gestation.

INTERVENTIONS

Fish oil capsules containing 900 mg omega-3 long-chain polyunsaturated fatty acids per day versus vegetable oil capsules consumed from enrolment until 34 weeks' gestation.

OUTCOME MEASURES

Early preterm birth (EPTB, <34 weeks' gestation) and preterm birth (PTB, <37 weeks' gestation) analysed using logistic regression models with interactions between treatment group and a range of maternal biological, clinical and demographic characteristics.

RESULTS

Omega-3 supplementation reduced the odds of EPTB for women with low total omega-3 status in early pregnancy (OR=0.30, 95% CI 0.10-0.93). No additional maternal characteristics influenced whether omega-3 supplementation reduced the odds of EPTB. For PTB, women were more likely to benefit from omega-3 supplementation if they were multiparous (OR=0.65, 95% CI 0.49-0.87) or avoided alcohol in the lead up to pregnancy (OR=0.62, 95% CI 0.45-0.86).

CONCLUSIONS

Our results support previous findings that women with low total omega-3 levels in early pregnancy are most likely to benefit from taking omega-3 supplements to reduce their risk of EPTB. Understanding how other maternal characteristics influence the effectiveness of omega-3 supplementation on reducing PTB requires further investigation.

TRIAL REGISTRATION NUMBER

ACTRN12613001142729.

Metabolomics during canine pregnancy and lactation

During pregnancy and parturition, female dogs have to cope with various challenges such as providing nutrients for the growth of the fetuses, hormonal changes, whelping, nursing, milk production, and uterine involution. Metabolomic research has been used to characterize the influence of several factors on metabolism such as inter- and intra-individual factors, feeding, aging, inter-breed differences, drug action, behavior, exercise, genetic factors, neuter status, and pathologic processes. Aim of this study was to identify metabolites showing specific changes in blood serum at the different phases of pregnancy and lactation. In total, 27 privately owned female dogs of 21 different breeds were sampled at six time points: during heat, in early, mid and late pregnancy, at the suspected peak of lactation and after weaning. A validated and highly automated canine-specific NMR metabolomics technology was utilized to quantitate 123 measurands. It was evaluated which metabolite concentrations showed significant changes between the different time points. Metabolites were then grouped into five clusters based on concentration patterns and biochemical relationships between the metabolites: high in mid-pregnancy, low in mid-pregnancy, high in late pregnancy, high in lactation, and low in lactation. Several metabolites such as albumin, glycoprotein acetyls, fatty acids, lipoproteins, glucose, and some amino acids show similar patterns during pregnancy and lactation as shown in humans. The patterns of some other parameters such as branched-chain amino acids, alanine and histidine seem to differ between these species. For most metabolites, it is yet unstudied whether the observed changes arise from modified resorption from the intestines, modified production, or metabolism in the maternal or fetal tissues. Hence, further species-specific metabolomic research may support a broader understanding of the physiological changes caused by pregnancy that are likely to be key for the normal fetal growth and development. Our findings provide a baseline of normal metabolic changes during healthy canine pregnancy and parturition. Combined with future metabolomics findings, they may help monitor vital functions of pre-, intra-, and post-partum bitches and may allow early detection of illness.

African American Women with Cardiometabolic Complications of Pregnancy Have Decreased Serum Abundance of Specialized Pro-Resolving Lipid Mediators and Endocannabinoids

African American (AA) women experience higher rates of maternal morbidity and mortality compared to US women of other racial/ ethnic groups. Cardiometabolic complications of pregnancy (including gestational diabetes, gestational hypertension, and preeclampsia) are leading contributors to maternal morbidity and mortality. Marked changes in circulating lipids are known to accompany cardiometabolic complications of pregnancy. Serum concentrations of docosahexaenoic acid (DHA) have been shown to be inversely correlated with risk for preeclampsia. DHA is a biosynthetic precursor of a class of specialized pro-resolving mediators (SPMs), resolvins, that have anti-inflammatory properties and are also associated with hypertensive disorders of pregnancy. We employed targeted lipidomics to characterize the distribution of DHA-containing phospholipids and SPMs in maternal serum collected in early and late pregnancy (8-14 weeks and 24-30 weeks gestation, respectively) to identify key lipids that are dysregulated during pregnancy in AA women who develop cardiometabolic complications. We identified a lipid signature in early pregnancy serum samples of AA women that is predictive of cardiometabolic complications of pregnancy with 74% accuracy. These are Resolvin D1, Resolvin E1, 2-AG, PGE2-glyerol ester, and 36:6 PC. These findings suggest that there are blood-based markers detectable in early pregnancy that can potentially identify persons at risk and tailor clinical interventions.

ISSFAL statement number 7 - Omega-3 fatty acids during pregnancy to reduce preterm birth

Globally, preterm birth is the leading cause of death in children under the age of 5 years and survivors may suffer life-long consequences. Following many years of investigation, there is strong evidence that a proportion of preterm births can be prevented by increasing maternal dietary omega-3 long chain polyunsaturated fatty acid (LCPUFA) intake during pregnancy. This Statement provides a synthesis of contemporary evidence on the role of omega-3 LCPUFA on prevention of preterm birth and is designed to provide fatty acid-specific knowledge and guidance for medical practitioners, midwives, health services, professional bodies and policy makers to consider for their contextual situations. The evidence synthesis, which underpins this statement, is based on the 2018 Cochrane systematic review with supplemental evidence from RCTs completed since that time as well as other systematic reviews. Heterogeneity between studies was explored to understand how the effect of omega-3 supplementation may vary in different population groups and by dose and type of omega-3 supplementation. Most trials were conducted in upper-middle or high-income countries and the evidence are most applicable in those settings. The evidence synthesis confirmed that omega-3 LCPUFA, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have an important role to play in determining gestational length in singleton pregnancies. Adequate intake of omega-3 LCPUFA in early pregnancy, consistent with existing nutritional guidelines, is associated with a lower risk of preterm and early preterm births for women with singleton pregnancies. Therefore, women with adequate omega-3 intakes in early pregnancy should maintain these intakes. Women who are low in omega-3 fatty acids will benefit most from omega-3 LCPUFA supplementation to reduce their risk of early birth. In such cases supplementation with a total of about 1000 mg of DHA plus EPA is effective at reducing risk of early birth, preferably with supplementation commencing before 20 weeks' gestation.

Evidence based recommendations for an optimal prenatal supplement for women in the US: vitamins and related nutrients

The blood levels of most vitamins decrease during pregnancy if un-supplemented, including vitamins A, C, D, K, B1, B3, B5, B6, folate, biotin, and B12. Sub-optimal intake of vitamins from preconception through pregnancy increases the risk of many pregnancy complications and infant health problems. In the U.S., dietary intake of vitamins is often below recommended intakes, especially for vitamin D, choline and DHA. Many studies suggest that insufficient vitamin intake is associated with a wide range of pregnancy complications (anemia, Cesarean section, depression, gestational diabetes, hypertension, infertility, preeclampsia, and premature rupture of membranes) and infant health problems (asthma/wheeze, autism, low birth weight, congenital heart defects, intellectual development, intrauterine growth restriction, miscarriage, neural tube defects, orofacial defects, and preterm birth). The primary goal of this paper is to review the research literature and propose evidence-based recommendations for the optimal level of prenatal supplementation for each vitamin for most women in the United States. A secondary goal was to compare these new recommendations with the levels of vitamins in over 180 commercial prenatal supplements. The analysis found that prenatal supplements vary widely in content, often contained only a subset of essential vitamins, and the levels were often below our recommendations. This suggests that increasing prenatal vitamin supplementation to the levels recommended here may reduce the incidence of many pregnancy complications and infant health problems which currently occur.

Recent advances in policy and practice translation of the evidence for additional omega-3 fatty acids and prematurity

PURPOSE OF REVIEW

This is a review of the most up-to-date research on the effectiveness of omega-3 fatty acids for reducing the risk of prematurity in well nourished women with access to high-quality obstetric care. It will provide an overview of the translation of the evidence on omega-3 screening into policy, and the latest research on how to implement the policy into practice.

RECENT FINDINGS

Findings of the included clinical studies support that omega-3 supplementation for women with a singleton pregnancy who have a low omega-3 status reduces the risk of early preterm birth.

SUMMARY

There is evidence that screening and providing appropriate advice to women with a singleton pregnancy who have a low omega-3 status can reduce their risk of early preterm birth, and avoiding supplementation for women who are replete will avoid unnecessary supplementation and potential harm.

Translating n-3 polyunsaturated fatty acid status from whole blood to plasma and red blood cells during pregnancy: Translating n-3 status across blood fractions in pregnancy

Women with low n-3 (omega-3) status in pregnancy can reduce their risk of early preterm birth (<34 weeks' gestation) through n-3 long chain polyunsaturated fatty acid (LCPUFA) supplementation. As investigators measure fatty acid status in different blood fractions, equations are needed to compare results across studies. Similarly, derived cut-points for defining low and replete n-3 status are needed to assist clinical interpretation during early pregnancy. Our aims were to develop equations to convert the percentage of total n-3 fatty acids, EPA+DHA and DHA between whole blood, plasma and red blood cells (RBC), and to derive cut-points for defining low and replete total n-3 fatty acid status in plasma and RBC from those already established in whole blood. Using blood samples from 457 pregnant women in a multicentre randomised controlled trial, equations for these interconversions were developed using simple linear regression models. Measures of n-3 fatty acid status in whole blood and plasma were strongly related (R² > 0.85), while more moderate relationships were observed between measures in whole blood and RBC (R² 0.55 - 0.71), or plasma and RBC (R² 0.55 - 0.63). Using the conversion equations, established cut-points for low and replete n-3 status in whole blood (<4.2% and >4.9% of total fatty acids) converted to <3.7% and >4.3% of plasma total fatty acids, and to <7.3% and >8.1% of RBC total fatty acids. Agreement to define low and replete n-3 status was better between whole blood and plasma, rather than between whole blood and RBC. Our data also show that total n-3 fatty acids in plasma and serum are interchangeable. We conclude that either whole blood or plasma total n-3 fatty acids can be used to define low status in pregnancy and identify women who will most benefit from n-3 LCPUFA supplementation to reduce their risk of early birth. Further research is needed to determine the clinical utility of other fatty acid measures in various blood lipid fractions.

Changes in fatty acid levels (saturated, monounsaturated and polyunsaturated) during pregnancy

BACKGROUND

During pregnancy a high amount of fatty acids (FA) is necessary to meet foetus demands, which vary during gestation. The present study describes the changes in maternal fatty acid concentrations during pregnancy in a sample of pregnant women.

METHODS

This is a longitudinal study of 479 pregnant women who were monitored from the first trimester to third trimester of pregnancy. Data on maternal characteristics were recorded and a serum sample was collected in each trimester. The fatty acid profile (saturated (SFA: total, lauric acid, myristic acid, palmitic acid, stearic acid), monounsaturated (MUFA: total, palmitoleic acid, oleic acid) and polyunsaturated fatty acids (PUFA: total omega-6 (n-6), linoleic acid, dihomo-γ-linolenic acid, arachidonic acid (AA), total omega-3 (n-3), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA)) was analysed with a gas chromatography-mass spectrometry combination.

RESULTS

From the first trimester to third trimester of pregnancy, a significant increase in total SFA, total MUFA and total n-6 PUFA was found. (p < 0.001). Nevertheless, the serum concentration of arachidonic acid (AA), eicosapentaenoic acid (EPA) and total n-3 PUFA decreased during gestation (p < 0.001). A statistically non-significant result was observed for the docosahexaenoic acid (DHA) serum concentration between the first and third trimesters of pregnancy. Significant correlations were observed between each total fatty acid concentrations of the first and third trimesters.

CONCLUSION

The circulating serum concentration of SFA, MUFA and n-6 PUFA increases during pregnancy, whereas essential fatty acids such as AA and EPA decrease, and DHA remains unchanged. Further research is necessary to understand the role played by FA throughout gestation.

Micronutrient supplementation in pregnancies following bariatric surgery: a practical review for clinicians

Patients who have undergone bariatric surgery are at high risk for nutritional deficiencies before and after surgery if no proper supplementation and close follow-up are maintained. As pregnancies after these surgeries are occurring more frequently, deficiencies imply risks for both mother and child. Nutritional needs for this specific population are different from that of patients with obesity or a non-bariatric population. This review provides a comprehensive summary of the most described vitamins and minerals during pregnancy, after bariatric surgery, and during pregnancy after bariatric surgery in order to summarize their specific needs and possible side effects and to provide a useful guideline to the involved caregivers.

Maternal polyunsaturated fatty acids during pregnancy and offspring brain development in childhood

BACKGROUND

Emerging evidence suggests an association of maternal PUFA concentrations during pregnancy with child cognitive and neuropsychiatric outcomes such as intelligence and autistic traits. However, little is known about prenatal maternal PUFAs in relation to child brain development, which may underlie these associations.

OBJECTIVES

We aimed to investigate the association of maternal PUFA status during pregnancy with child brain morphology, including volumetric and white matter microstructure measures.

METHODS

This study was embedded in a prospective population-based study. In total, 1553 mother-child dyads of Dutch origin were included. Maternal plasma glycerophospholipid PUFAs were assessed in midpregnancy. Child brain morphologic outcomes, including total gray and white matter volumes, as well as white matter microstructure quantified by global fractional anisotropy and mean diffusivity, were measured using MRI (including diffusion tensor imaging) at age 9-11 y.

RESULTS

Maternal ω-3 (n-3) long-chain PUFA (LC-PUFA) concentrations during pregnancy had an inverted U-shaped relation with child total gray volume (linear term: β: 16.7; 95% CI: 2.0, 31.5; quadratic term: β: -1.1; 95% CI: -2.1, -0.07) and total white matter volume (linear term: β: 15.7; 95% CI: 3.6, 27.8; quadratic term: β: -1.0; 95% CI: -1.8, -0.16). Maternal gestational ω-6 LC-PUFA concentrations did not predict brain volumetric differences in children, albeit the linolenic acid concentration was inversely associated with child total white matter volume. Maternal PUFA status during pregnancy was not related to child white matter microstructure.

CONCLUSIONS

Sufficient maternal ω-3 PUFAs during pregnancy may be related to more optimal child brain development in the long term. In particular, exposure to lower ω-3 PUFA concentrations in fetal life was associated with less brain volume in childhood. Maternal ω-6 LC-PUFAs were not related to child brain morphology.

Dietary alpha linolenic acid in pregnant mice and during weaning increases brain docosahexaenoic acid and improves recognition memory in the offspring

Docosahexaenoic acid (DHA) is critical for normal brain development and function. DHA is in danger of being significantly reduced in the human food supply, and the question of whether its metabolic precursor, the essential n-3 alpha linolenic acid (ALA) during pregnancy, can support fetal brain DHA levels for optimal neurodevelopment, is fundamental. Female mice were fed either ALA-enriched or Control diet during pregnancy and lactation. The direct effect of maternal dietary ALA on lipids was analyzed in liver, red blood cells, brain and brain vasculature, together with genes of fatty acid metabolism and transport in three-week-old offspring. The long-term effect of maternal dietary ALA on brain fatty acids and memory was studied in 19-week-old offspring. Three-week-old ALA offspring showed higher levels of n-3 fatty acids in liver, red blood cell, blood-brain barrier (BBB) vasculature and brain parenchyma, DHA enrichment in brain phospholipids and higher gene and protein expression of the DHA transporter, major facilitator superfamily domain containing 2a, compared to Controls. 19-week-old ALA offspring showed higher brain DHA levels and better memory performance than Controls. The increased brain DHA levels induced by maternal dietary ALA during pregnancy-lactation, together with the up-regulated levels of major facilitator superfamily domain containing 2a, may indicate a mode for greater DHA uptake with long-term impact on better memory in ALA offspring.

Effects of Maternal Nutritional Supplements and Dietary Interventions on Placental Complications: An Umbrella Review, Meta-Analysis and Evidence Map

The placenta is a vital, multi-functional organ that acts as an interface between maternal and fetal circulation during pregnancy. Nutritional deficiencies during pregnancy alter placental development and function, leading to adverse pregnancy outcomes, such as pre-eclampsia, infants with small for gestational age and low birthweight, preterm birth, stillbirths and maternal mortality. Maternal nutritional supplementation may help to mitigate the risks, but the evidence base is difficult to navigate. The primary purpose of this umbrella review is to map the evidence on the effects of maternal nutritional supplements and dietary interventions on pregnancy outcomes related to placental disorders and maternal mortality. A systematic search was performed on seven electronic databases, the PROSPERO register and references lists of identified papers. The results were screened in a three-stage process based on title, abstract and full-text by two independent reviewers. Randomized controlled trial meta-analyses on the efficacy of maternal nutritional supplements or dietary interventions were included. There were 91 meta-analyses included, covering 23 types of supplements and three types of dietary interventions. We found evidence that supports supplementary vitamin D and/or calcium, omega-3, multiple micronutrients, lipid-based nutrients, and balanced protein energy in reducing the risks of adverse maternal and fetal health outcomes. However, these findings are limited by poor quality of evidence. Nutrient combinations show promise and support a paradigm shift to maternal dietary balance, rather than single micronutrient deficiencies, to improve maternal and fetal health. The review is registered at PROSPERO (CRD42020160887).

Low Omega-3 intake is associated with high rates of depression and preterm birth on the country level

Low circulating levels of long chain omega-3 polyunsaturated fatty acids (LC omega-3 PUFA) have been linked to major depressive disorder (MDD) and preterm birth (PTB), and prenatal depression associates with PTB. We therefore hypothesized that low Omega-3 intake would associate with higher MDD and PTB rates on the country-level. To test this hypothesis, we obtained country-level estimates for omega-3 intake, MDD prevalence, PTB rate, and per capita income for 184 countries in 2010. We then estimated the LC omega-3 PUFA levels that these intakes produce by accounting for direct consumption and the endogenous conversion of ingested plant-based precursors. Penalized splines indicated that MDD and PTB rates decreased linearly with increasing LC omega-3 PUFA, up to ~ 1000 mg/day for MDD and up to ~ 550 mg/day for PTB. Adjusted linear regression models below these thresholds revealed that a one standard deviation increase in LC omega-3 PUFA (380 mg/day) was associated with an MDD decrease of 5 cases/1000 people and a PTB decrease of 15 cases/1000 livebirths. In light of the extensive prior evidence on the individual-level, these findings indicate that low intake of LC omega-3 PUFA and its precursors may be elevating MDD and PTB rates in 85% of the countries studied.

Effect of omega-3 lcpufa supplementation on maternal fatty acid and oxylipin concentrations during pregnancy

INTRODUCTION

Omega-3 long chain polyunsaturated fatty acids (LCPUFA) have been associated with a reduction in risk for preterm birth. However, there is limited understanding of how fatty acids and their bioactive derivatives (oxylipins) change over the course of pregnancy. Here we document the changes in concentration of fatty acids and oxylipins during pregnancy and how fatty acid status and oxylipin concentrations are affected by supplementation with omega-3 LCPUFA. We also investigate the degree to which fatty acid and oxylipin changes across pregnancy are influenced by baseline omega-3 status.

MATERIALS AND METHODS

We profiled the fatty acids in all lipids in dried blood spots (total blood fatty acids) by gas chromatography and free (unesterified) fatty acids and their associated oxylipins in separate dried blood spot samples by LC-MS-MS collected from a random sample of 1263 women with a singleton pregnancy who participated in the ORIP (Omega-3 fats to Reduce the Incidence of Prematurity) trial. ORIP is a double-blind, randomized controlled trial involving 5544 participants and designed to determine the effect of supplementing the diets of pregnant women with omega-3 LCPUFA on the incidence of early preterm birth. Maternal whole blood finger prick samples were collected at baseline (~14 weeks gestation) and at completion of the study intervention period (34 weeks gestation).

RESULTS

The concentration of most total and free polyunsaturated fatty acids and their associated oxylipins declined over the course of pregnancy. Omega-3 LCPUFA supplementation increased total DHA and 7-HDHA and mitigated the decline in free DHA, 4-HDHA and 14-HDHA. The intervention had minimal or no effect on free EPA, LA, AA and their associated oxylipins. Omega-3 LCPUFA supplementation in women with higher omega-3 status at baseline was associated with a significant increase in 7-HDHA and 4-HDHA between the treatment and control whereas there were no differences between groups in 7-HDHA and 4-HDHA in women with intermediate or lower baseline omega-3 status.

CONCLUSION

Our data suggest a differential response with or without omega-3 supplementation for DHA and DHA-derived oxylipins, which may have an important role to play in modulating pregnancy duration. Further work is needed to understand their role, which may allow us to better tailor omega-3 supplementation for preterm birth prevention.

Omega-3 fatty acid supplement use and oxidative stress levels in pregnancy

Oxidative stress is a biological imbalance in reactive oxygen species and antioxidants. Increased oxidative stress during pregnancy has been associated with adverse birth outcomes. Omega-3 fatty acid (n-3 FA) supplementation may decrease oxidative stress; however, this relationship is seldom examined during pregnancy. This study assessed the association between n-3 FA supplement use during pregnancy and urinary oxidative stress biomarker concentrations. Data came from The Infant Development and the Environment Study (TIDES), a prospective cohort study that recruited pregnant women in 4 US cities between 2010-2012. Third trimester n-3 FA intake was self-reported. Third trimester urinary 8-iso-prostaglandin F2α (8-iso-PGF2α) was measured as an oxidative stress biomarker. Additionally, we measured the major metabolite of 8-iso-PGF2α and Prostaglandin F2α (PGF2α) and utilized the 8-iso-PGF2α to PGF2α ratio to calculate the change in 8-iso-PGF2α reflecting oxidative stress versus inflammation. Adjusted linear models were used to determine associations with control for confounding. Of 725 women, 165 reported n-3 FA supplement use in the third trimester. In adjusted linear models, n-3 FA use was associated with 10.2% lower levels of 8-iso-PGF2α (95% Confidence Interval [CI]: -19.6, 0.25) and 10.3% lower levels of the metabolite (95% CI: -17.1, -2.91). No associations were observed with PGF2α. The lower levels of 8-iso-PGF2α appeared to reflect a decrease in oxidative stress (percent change with supplement use: -18.7, 95% CI: -30.1, -5.32) rather than inflammation. Overall, third trimester n-3 FA intake was associated with lower concentrations of 8-iso-PGF2α and its metabolite, suggesting a decrease in maternal oxidative stress during pregnancy.

Longitudinal profiles of plasma eicosanoids during pregnancy and size for gestational age at delivery: A nested case-control study

BACKGROUND

Inflammation during pregnancy is hypothesized to influence fetal growth. Eicosanoids, an important class of lipid mediators derived from polyunsaturated fatty acids, can act as both direct influences and biomarkers of inflammation through a variety of biological pathways. However, quantifying these distinct inflammatory pathways has proven difficult. We aimed to characterize a comprehensive panel of plasma eicosanoids longitudinally across gestation in pregnant women and to determine whether levels differed by infant size at delivery.

METHODS AND FINDINGS

Our data come from a case-control study of 90 pregnant women nested within the LIFECODES prospective birth cohort study conducted at Brigham and Women's Hospital in Boston, Massachusetts. This study included 31 women who delivered small for gestational age (SGA) babies (SGA, ≤10th percentile), 28 who delivered large for gestational age (LGA) babies (≥90th percentile), and 31 who delivered appropriate for gestational age (AGA) babies (controls, >10th to <90th percentile). All deliveries occurred between 2010 and 2017. Most participants were in their early 30s (median age: 33 years), of white (60%) or black (20%) race/ethnicity, and of normal pre-pregnancy BMI (median BMI: 23.5 kg/m2). Women provided non-fasting plasma samples during 3 prenatal study visits (at median 11, 25, and 35 weeks gestation) and were analyzed for a panel of eicosanoids. Eicosanoids were grouped by biosynthetic pathway, defined by (1) the fatty acid precursor, including linoleic acid (LA), arachidonic acid (AA), docosahexaenoic acid (DHA), or eicosapentaenoic acid (EPA), and (2) the enzyme group, including cyclooxygenase (COX), lipoxygenase (LOX), or cytochrome P450 (CYP). Additionally, the concentrations of the 4 fatty acids (LA, AA, DHA, and EPA) were measured in maternal plasma. Analytes represent lipids from non-esterified plasma. We examined correlations among eicosanoids and trajectories across pregnancy. Differences in longitudinal concentrations between case groups were examined using Bayesian linear mixed effects models, which included participant-specific random intercepts and penalized splines on gestational age. Results showed maternal plasma levels of eicosanoids and fatty acids generally followed U-shaped curve patterns across gestation. Bayesian models showed that associations between eicosanoids and case status varied by biosynthetic pathway. Eicosanoids derived from AA via the CYP and LOX biosynthetic pathways were positively associated with SGA. The adjusted mean concentration of 12-HETE, a LOX pathway product, was 56.2% higher (95% credible interval 6.6%, 119.1%) among SGA cases compared to AGA controls. Eicosanoid associations with LGA were mostly null, but negative associations were observed with eicosanoids derived from AA by LOX enzymes. The fatty acid precursors had estimated mean concentrations 41%-97% higher among SGA cases and 33%-39% lower among LGA cases compared to controls. Primary limitations of the study included the inability to explore the potential periods of susceptibility of eicosanoids on infant size due to limited sample size, along with the use of infant size at delivery instead of longitudinal ultrasound measures to estimate fetal growth.

CONCLUSIONS

In this nested case-control study, we found that eicosanoids and fatty acids systematically change in maternal plasma over pregnancy. Eicosanoids from specific inflammation-related pathways were higher in mothers of SGA cases and mostly similar in mothers of LGA cases compared to controls. These findings can provide deeper insight into etiologic mechanisms of abnormal fetal growth outcomes.

Omega-3 Fatty Acids in Pregnancy-The Case for a Target Omega-3 Index

Scientific societies recommend increasing intake of docosahexaenoic acid (DHA) by 200 mg/day during pregnancy. However, individually, clinical events correlate quite strongly with levels of eicosapentaenoic acid (EPA) and DHA in blood, but these levels poorly correlate with amounts ingested. EPA and DHA in erythrocytes (Omega-3 Index) have a low biologic variability. If analyzed with a standardized analytical procedure (HS-Omega-3 Index^®), analytical variability is low. Thus, the largest database of any fatty acid analytical method was provided. Pregnant women in Germany had a mean Omega-3 Index below the target range suggested for cardiovascular disease of 8–11%, with large interindividual variation, and quite independent of supplementation with EPA and DHA. In Germany, premature birth is a major health issue. Premature birth and other health issues of pregnant women and their offspring correlate with levels of EPA and DHA in blood and can be reduced by increasing intake of EPA and DHA, according to individual trials and pertinent meta-analyses. Very high intake or levels of EPA and DHA may also produce health issues, like bleeding, prolonged gestation, or even premature birth. While direct evidence remains to be generated, evidence from various scientific approaches supports that the target range for the Omega-3 Index of 8–11% might also pertain to pregnancy and lactation.

Influence of clinical characteristics on maternal DHA and other polyunsaturated fatty acid status in pregnancy: A systematic review

INTRODUCTION

Omega-3 DHA is important for the prevention of preterm birth, however there is limited knowledge of the determinants of omega-3 status during pregnancy. The primary objective of this systematic review was to synthesise data from existing studies assessing relationships between clinical factors and maternal DHA status.

MATERIALS AND METHODS

The Medline, Embase, Amed, and CINAHL databases were searched for studies reporting measures of maternal omega-3 status and one or more clinical characteristics.

RESULTS

Eighteen studies were included in the final analyses. Factors associated with a higher BMI (overweight, higher gestational weight gain, gestational diabetes), or lower parity were each associated with higher omega-3 status in the majority of studies, with mixed findings for other comparisons.

DISCUSSION

Inconsistent findings between studies make it difficult to draw clear conclusions about the relationship between clinical factors and maternal omega-3 DHA status. However, maternal overweight and associated metabolic conditions may increase lipid metabolism.

Influence of sociodemographic, lifestyle and genetic characteristics on maternal DHA and other polyunsaturated fatty acid status in pregnancy: A systematic review

INTRODUCTION

Omega-3 DHA is important for the prevention of preterm birth, however there is limited knowledge of the determinants of omega-3 status during pregnancy. The primary objective of this systematic review was to synthesise data from existing studies assessing relationships between sociodemographic, diet, lifestyle and genetic factors and maternal DHA status.

MATERIALS AND METHODS

The Medline, Embase, Amed, and CINAHL databases were searched for studies reporting measures of maternal omega-3 status and a sociodemographic/lifestyle/genetic characteristic.

RESULTS

Twenty-two studies were included in the final analyses. Higher dietary fish consumption/PUFA intake, higher education level and an older maternal age were associated with higher maternal omega-3 status. Higher alcohol intake, smoking and FADS genotype were each associated with lower maternal omega-3 status.

DISCUSSION

Differences in findings between studies make it difficult to draw clear conclusions about the relationship between these factors and maternal omega-3 DHA status, although socioeconomic status may play a role.

Plasma phospholipid n-3 and n-6 polyunsaturated fatty acids in relation to cardiometabolic markers and gestational diabetes: A longitudinal study within the prospective NICHD Fetal Growth Studies

BACKGROUND

Despite dietary recommendations of polyunsaturated fatty acids (PUFAs) for cardiometabolic health, n-3 and n-6 PUFAs and their interplay in relation to diabetes risk remain debated. Importantly, data among pregnant women are scarce. We investigated individual plasma phospholipid n-3 and n-6 PUFAs in early to midpregnancy in relation to subsequent risk of gestational diabetes mellitus (GDM).

METHODS AND FINDINGS

Within the National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singleton Cohort (n = 2,802), individual plasma phospholipid n-3 and n-6 PUFAs levels were measured at gestational weeks (GWs) 10-14, 15-26, 23-31, and 33-39 among 107 GDM cases (ascertained on average at GW 27) and 214 non-GDM controls. Conditional logistic regression was used, adjusting for major risk factors for GDM. After adjusting for covariates, individual n-3 eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) were inversely correlated with insulin-resistance markers, whereas individual n-6 dihomo-gamma-linolenic acid (DGLA) was positively correlated with insulin-resistance markers. At GW 15-26, a standard deviation (SD) increase in total n-3 PUFAs and individual n-3 DPA was associated with a 36% (adjusted odds ratio 0.64; 95% CI 0.42-0.96; P = 0.042) and 33% (0.67; 95% CI 0.45-0.99; P = 0.047) lower risk of GDM, respectively; however, the significance did not persist after post hoc false-discovery rate (FDR) correction (FDR-corrected P values > 0.05). Associations between total n-6 PUFAs and GDM were null, whereas associations with individual n-6 PUFAs were differential. Per SD increase, gamma-linolenic acid (GLA) at GWs 10-14 and DGLA at GWs 10-14 and 15-26 were significantly associated with a 1.40- to 1.95-fold higher risk of GDM, whereas docosatetraenoic acid (DTA) at GW 15-26 was associated with a 45% (0.55; 95% CI 0.37-0.83) lower risk of GDM (all FDR-corrected P values < 0.05). Null associations were observed for linoleic acid (LA) in either gestational window in relation to risk of GDM. Women with high (≥median) n-3 PUFAs and low (<median) n-6 PUFAs levels had a 64% (95% CI 0.14-0.95; P value = 0.039) lower risk of GDM versus women with low n-3 and high n-6 PUFAs. Limitations include the inability to distinguish between exogenous and endogenous influences on circulating PUFA levels and the lack of causality inherent in observational studies.

CONCLUSIONS

Our findings may suggest a potential role of primarily endogenously metabolized plasma phospholipid n-6 PUFAs including GLA, DGLA, and DTA in early to midpregnancy in the development of GDM. Null findings on primarily diet-derived n-3 EPA and DHA and n-6 LA do not provide strong evidence to suggest a beneficial role in prevention of GDM, although not excluding the potential benefit of EPA and DHA on glucose-insulin homeostasis given the inverse associations with insulin-resistance markers. Our findings highlight the importance of assessing individual circulating PUFAs to investigate their distinct pathophysiologic roles in glucose homeostasis in pregnancy.