Plasma Concentrations of Long Chain N-3 Fatty Acids in Early and Mid-Pregnancy and Risk of Early Preterm Birth

Determinants of prematurity in urban Indonesia: a meta-analysis

OBJECTIVES

Indonesia is the fifth country with the highest number of preterm births worldwide. More than a third of neonatal deaths in Indonesia were attributed to preterm birth. Residential areas affected the occurrence of preterm birth due to differing socioeconomic and environmental conditions. Many studies have investigated the determinants of prematurity in Indonesia, however, most of them were performed in rural areas. This study is the first meta-analysis describing the determinants of preterm birth in urban Indonesia, which aimed to become the foundation upon implementing the most suitable preventative measure and policy to reduce the rate of preterm birth.

METHODS

We collected all published papers investigating the determinants of preterm birth in urban Indonesia from PubMed MEDLINE and EMBASE, using keywords developed from the following key concepts: "preterm birth", "determinants", "risk factors", "Indonesia" and the risk factors, such as "high-risk pregnancy", "anemia", "pre-eclampsia", and "infections". Exclusion criteria were multicenter studies that did not perform a specific analysis on the Indonesian population or did not separate urban and rural populations in their analysis, and articles not available in English or Indonesian. The Newcastle Ottawa Scale was used to assess the risk of bias. This systematic review was registered in PROSPERO.

RESULTS

Sixteen articles were included in the analysis and classified into five categories: genetic factors, nutrition, smoking, pregnancy characteristics or complications, and disease-related characteristics.

CONCLUSIONS

Our meta-analysis revealed adolescent pregnancy, smoking, eclampsia, bacterial vaginosis, LC-PUFA, placental vitamin D, and several minerals as the significant determinants of preterm birth in urban Indonesia.

ω-3 Polyunsaturated Fatty Acid Status Testing in Humans: A Narrative Review of Commercially Available Options

There is an increasing body of evidence supporting a link between low intakes of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) and numerous diseases and health conditions. However, few people are achieving the levels of fish/seafood or eicosapentaenoic acid and docosahexaenoic acid intake recommended in national and international guidelines. Knowledge of a person's ω-3 LCPUFA status will benefit the interpretation of research results and could be expected to lead to an increased effort to increase intake. Dietary intake survey methods are often used as a surrogate for measuring ω-3 PUFA tissue status and its impact on health and functional outcomes. However, because individuals vary widely in their ability to digest and absorb ω-3 PUFA, analytical testing of biological samples is desirable to accurately evaluate ω-3 PUFA status. Adipose tissue is the reference biospecimen for measuring tissue fatty acids, but less-invasive methods, such as measurements in whole blood or its components (e.g., plasma, serum, red blood cell membranes) or breast milk are often used. Numerous commercial laboratories provide fatty acid testing of blood and breast milk samples by different methods and present their results in a variety of reports such as a full fatty acid profile, ω-3 and ω-6 fatty acid profiles, fatty acid ratios, as well as the Omega-3 Index, the Holman Omega-3 Test, OmegaScore, and OmegaCheck, among others. This narrative review provides information about the different ways to measure ω-3 LCPUFA status (including both dietary assessments and selected commercially available analytical tests of blood and breast milk samples) and discusses evidence linking increased ω-3 LCPUFA intake or status to improved health, focusing on cardiovascular, neurological, pregnancy, and eye health, in support of recommendations to increase ω-3 LCPUFA intake and testing.

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.

DHA supplementation and pregnancy complications

Docosahexaenoic acid (DHA) supplementation is recommended for women during pregnancy because of its neurological, visual, and cognitive effects. Previous studies have suggested that DHA supplementation during pregnancy may prevent and treat certain pregnancy complications. However, there are contradictions in the current related studies, and the specific mechanism by which DHA acts remains unclear. This review summarizes the research on the relationship between DHA intake during pregnancy and preeclampsia, gestational diabetes mellitus, preterm birth, intrauterine growth restriction, and postpartum depression. Furthermore, we explore the impact of DHA intake during pregnancy on the prediction, prevention, and treatment of pregnancy complications as well as its impact on offspring neurodevelopment. Our results suggest that there is limited and controversial evidence for the protective effect of DHA intake on pregnancy complications, with the exception of preterm birth and gestational diabetes mellitus. However, additional DHA supplementation may improve long-term neurodevelopmental outcomes in the offspring of women with pregnancy complications.

Development and internal validation of a non-invasive clinical tool to predict sufficient omega-3 levels in early pregnancy

BACKGROUND

Complications from preterm birth (PTB) are the leading cause of death and disability in those under five years. Whilst the role of omega-3 (n-3) supplementation in reducing PTB is well-established, growing evidence suggests supplementation use in those replete may increase the risk of early PTB.

AIM

To develop a non-invasive tool to identify individuals with total n-3 serum levels above 4.3% of total fatty acids in early pregnancy.

METHODS

We conducted a prospective observational study recruiting 331 participants from three clinical sites in Newcastle, Australia. Eligible participants (n = 307) had a singleton pregnancy between 8 and 20 weeks' gestation at recruitment. Data on factors associated with n-3 serum levels were collected using an electronic questionnaire; these included estimated intake of n-3 (including food type, portion size, frequency of consumption), n-3 supplementation, and sociodemographic factors. The optimal cut-point of estimated n-3 intake that predicted mothers with total serum n-3 levels likely above 4.3% was developed using multivariate logistic regression, adjusting for maternal age, body mass index, socioeconomic status, and n-3 supplementation use. Total serum n-3 levels above 4.3% was selected as previous research has demonstrated that mothers with these levels are at increased risk of early PTB if they take additional n-3 supplementation during pregnancy. Models were evaluated using various performance metrics including sensitivity, specificity, area under receiver operator characteristic (AUROC) curve, true positive rate (TPR) at 10% false positive rate (FPR), Youden Index, Closest to (0,1) Criteria, Concordance Probability, and Index of Union. Internal validation was performed using 1000-bootstraps to generate 95% confidence intervals for performance metrics generated.

RESULTS

Of 307 eligible participants included for analysis, 58.6% had total n-3 serum levels above 4.3%. The optimal model had a moderate discriminative ability (AUROC 0.744, 95% CI 0.742-0.746) with 84.7% sensitivity, 54.7% specificity and 37.6% TPR at 10% FPR.

CONCLUSIONS

Our non-invasive tool was a moderate predictor of pregnant women with total serum n-3 levels above 4.3%; however, its performance is not yet adequate for clinical use.

TRIAL REGISTRATION

This trial was approved by the Hunter New England Human Research Ethics Committee of the Hunter New England Local Health District (Reference 2020/ETH00498 on 07/05/2020 and 2020/ETH02881 on 08/12/2020).

Bioactive lipid mediators in plasma are predictors of preeclampsia irrespective of aspirin therapy

There are few early biomarkers to identify pregnancies at risk of preeclampsia (PE) and abnormal placental function. In this cross-sectional study, we utilized targeted ultra-performance liquid chromatography-ESI MS/MS and a linear regression model to identify specific bioactive lipids that serve as early predictors of PE. Plasma samples were collected from 57 pregnant women prior to 24-weeks of gestation with outcomes of either PE (n = 26) or uncomplicated term pregnancies (n = 31), and the profiles of eicosanoids and sphingolipids were evaluated. Significant differences were revealed in the eicosanoid, (±)11,12 DHET, as well as multiple classes of sphingolipids; ceramides, ceramide-1-phosphate, sphingomyelin, and monohexosylceramides; all of which were associated with the subsequent development of PE regardless of aspirin therapy. Profiles of these bioactive lipids were found to vary based on self-designated race. Additional analyses demonstrated that PE patients can be stratified based on the lipid profile as to PE with a preterm birth linked to significant differences in the levels of 12-HETE, 15-HETE, and resolvin D1. Furthermore, subjects referred to a high-risk OB/GYN clinic had higher levels of 20-HETE, arachidonic acid, and Resolvin D1 versus subjects recruited from a routine, general OB/GYN clinic. Overall, this study shows that quantitative changes in plasma bioactive lipids detected by ultra-performance liquid chromatography-ESI-MS/MS can serve as an early predictor of PE and stratify pregnant people for PE type and risk.

A modular systematic review of antenatal interventions to address undernutrition during pregnancy in the prevention of low birth weight

BACKGROUND

Poor nutrition during pregnancy can lead to adverse birth outcomes including low birth weight (LBW).

OBJECTIVE

This modular systematic review aimed to provide evidence for the effects of seven antenatal nutritional interventions on the risks of LBW, preterm birth (PTB), small-for-gestational-age (SGA) and stillbirth (SB).

METHODS

We searched MEDLINE, Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials and CINAHL Complete between April and June 2020, with a further update in September 2022 (Embase only). We included randomized controlled trials (RCTs) and reviews of RCTs to estimate the effect sizes of the selected interventions on the four birth outcomes.

RESULTS

Evidence suggests that balanced protein and energy (BPE) supplementation for pregnant women with undernutrition can reduce the risk of LBW, SGA and SB. Evidence from low and lower middle-income countries (MIC) suggests that multiple micronutrient (MMN) supplementation can reduce the risk of LBW and SGA in comparison with iron or iron and folic acid supplementation and lipid-based nutrient supplements (LNS) with any quantity of energy can reduce the risk of LBW in comparison with MMN supplementation. Evidence from high and upper MIC suggests that supplementation with omega-3 fatty acids (O3FA) can reduce the risk and supplementation with high-dose calcium might possibly reduce the risk of LBW and PTB. Antenatal dietary education programs might possibly reduce the risk of LBW in comparison with standard-of-care. No RCTs were identified for monitoring weight gain followed by interventions to support weight gain in women who are underweight.

CONCLUSIONS

Provision of BPE, MMN and LNS to pregnant women in populations with undernutrition can reduce the risk of LBW and related outcomes. The benefits of O3FA and calcium supplementation to this population require further investigation. Targeting interventions to pregnant women who are not gaining weight has not been tested with RCTs.

Association between maternal fish consumption during pregnancy and preterm births: the Japan Environment and Children's Study

BACKGROUND

Fish are a rich source of essential nutrients that protect against preterm birth. However, as fish can absorb environmental pollutants, their consumption can also increase the risk of preterm birth. This study aimed to assess whether maternal fish consumption during pregnancy is associated with preterm birth in a nationwide large Japanese cohort that consumed relatively high amounts and many types of fish.

METHODS

This study included 81,428 mother-child pairs enrolled in a nationwide prospective Japanese birth cohort study. Fish consumption was assessed using a validated food frequency questionnaire. Multivariate logistic regression was used to investigate the association of total consumption of fish, fatty fish and lean fish, fish paste, and seafood and clams with preterm birth, adjusted for potential confounders.

RESULTS

There was no association between overall fish consumption and preterm births. However, the highest quintile of fish paste consumption was significantly associated with an increased risk of preterm birth (odds ratio [OR]: 1.11; 95% confidence interval [CI: 1.04, 1.17]). The consumption of baked fish paste at least three times per week was significantly associated with preterm birth (OR: 1.20; 95% CI: 1.03, 1.40). Consumption of other types of fish, except fish paste, was not significantly associated with preterm birth risk.

CONCLUSIONS

Fish paste consumption may increase the risk of preterm birth. Further studies are required to confirm this association.

Plasma miRNA Profile in High Risk of Preterm Birth during Early and Mid-Pregnancy

In recent years evidence has been accumulated showing that miRNAs can act as potential biomarkers or targets for therapy of preterm birth, one of the most important problems in modern obstetrics. We have performed a prospective study of the miRNA profile in the plasma during the first and second trimesters in pregnant women with high risk of preterm birth (n = 13 cases and n = 11 controls). For the study group plasma blood samples at 9–13 weeks before diagnosis and at 22–24 weeks after start of therapy were selected. Using high-throughput sequencing technology we detected differences in the levels of 15 miRNAs (3 upregulated—hsa-miR-122-5p, hsa-miR-34a-5p, hsa-miR-34c-5p; 12 downregulated—hsa-miR-487b-3p, hsa-miR-493-3p, hsa-miR-432-5p, hsa-miR-323b-3p, hsa-miR-369-3p, hsa-miR-134-5p, hsa-miR-431-5p, hsa-miR-485-5p, hsa-miR-382-5p, hsa-miR-369-5p, hsa-miR-485-3p, hsa-miR-127-3p) (log₂(FC) ≥ 1.5; FDR ≤ 0.05) during the first trimester compared with the control (non-high-risk of preterm birth pregnant women). All downregulated miRNAs in the first trimester from the placenta-specific C14MC cluster. During the second trimester no differentially expressed miRNAs were found. Our results suggest that the miRNA profile in plasma during early pregnancy may predict a high risk of preterm birth, which is important in preventing gestational problems as early as possible.

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.

DHA turnover in pregnant women using the natural abundance variation of 13C: a pilot study

The importance of DHA intake to support fetal development and maternal health is well established. In this pilot study we applied the natural abundance approach to determine the contribution of 200 mg/day of DHA supplement to the plasma DHA pool in 19 healthy pregnant women on a free diet.Women received DHA, from pregnancy week 20 until delivery, from an algal source (N=13, Algae group) or from fish oil (N=6, Fish group) with slightly different content of 13C.We measured plasma phospholipids DHA 13C:12C ratio (reported as δ13C) prior to supplementation (T0), after 10 (T1) and 90 days (T2) and prior to delivery (T3).The δ13C of DHA in algae and fish supplements were -15.8±0.2 mUr and -25.3±0.2 mUr (p<0.001).DHA δ13C in the Algae group increased from -27.7±1.6 mUr (T0) to -21.9±2.2 mUr (T3) (p<0.001), whereas there were not significant changes in the Fish group (-27.8±0.9 mUr at T0 and -27.3±1.1 mUr at T3, p=0.09).In the Algae group 200 mg/day of DHA contributed to the plasma phospholipid pool by a median value of 53% (31-75% minimum and maximum). This estimation was not possible in the fish group.Our results demonstrate the feasibility of assessing the contribution of DHA from an algal source to the plasma DHA pool in pregnant women by the natural abundance approach. Plasma δ13C DHA did not change when consuming DHA of fish origin, with almost the same δ13C value of that of the pre-supplementation plasma δ13C DHA.

Is there a maternal blood biomarker that can predict spontaneous preterm birth prior to labour onset? A systematic review

Introduction

The ability to predict spontaneous preterm birth (sPTB) prior to labour onset is a challenge, and it is currently unclear which biomarker(s), may be potentially predictive of sPTB, and whether their predictive power has any utility. A systematic review was conducted to identify maternal blood biomarkers of sPTB.

Methods

This study was conducted according to PRISMA protocol for systematic reviews. Four databases (MEDLINE, EMBASE, CINAHL, Scopus) were searched up to September 2021 using search terms: “preterm labor”, “biomarker” and “blood OR serum OR plasma”. Studies assessing blood biomarkers prior to labour onset against the outcome sPTB were eligible for inclusion. Risk of bias was assessed based on the Newcastle Ottawa scale. Increased odds of sPTB associated with maternal blood biomarkers, as reported by odds ratios (OR), or predictive scores were synthesized. This review was not prospectively registered.

Results

Seventy-seven primary research articles met the inclusion criteria, reporting 278 unique markers significantly associated with and/or predictive of sPTB in at least one study. The most frequently investigated biomarkers were those measured during maternal serum screen tests for aneuploidy, or inflammatory cytokines, though no single biomarker was clearly predictive of sPTB based on the synthesized evidence. Immune and signaling pathways were enriched within the set of biomarkers and both at the level of protein and gene expression.

Conclusion

There is currently no known predictive biomarker for sPTB. Inflammatory and immune biomarkers show promise, but positive reporting bias limits the utility of results. The biomarkers identified may be more predictive in multi-marker models instead of as single predictors. Omics-style studies provide promising avenues for the identification of novel (and multiple) biomarkers. This will require larger studies with adequate power, with consideration of gestational age and the heterogeneity of sPTB to identify a set of biomarkers predictive of sPTB.

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.

Maternal and Neonatal Polyunsaturated Fatty Acid Intake and Risk of Neurodevelopmental Impairment in Premature Infants

The N3 and N6 long chain polyunsaturated fatty acids (LCPUFA) docosahexaenoic acid (DHA) and arachidonic acid (AA) are essential for proper neurodevelopment in early life. These fatty acids are passed from mother to infant via the placenta, accreting into fetal tissues such as brain and adipose tissue. Placental transfer of LCPUFA is highest in the final trimester, but this transfer is abruptly severed with premature birth. As such, efforts have been made to supplement the post-natal feed of premature infants with LCPUFA to improve neurodevelopmental outcomes. This narrative review analyzes the current body of evidence pertinent to neurodevelopmental outcomes after LCPUFA supplementation in prematurely born infants, which was identified via the reference lists of systematic and narrative reviews and PubMed search engine results. This review finds that, while the evidence is weakened by heterogeneity, it may be seen that feed comprising 0.3% DHA and 0.6% AA is associated with more positive neurodevelopmental outcomes than LCPUFA-deplete feed. While no new RCTs have been performed since the most recent Cochrane meta-analysis in 2016, this narrative review provides a wider commentary; the wider effects of LCPUFA supplementation in prematurely born infants, the physiology of LCPUFA accretion into preterm tissues, and the physiological effects of LCPUFA that affect neurodevelopment. We also discuss the roles of maternal LCPUFA status as a modifiable factor affecting the risk of preterm birth and infant neurodevelopmental outcomes. To better understand the role of LCPUFAs in infant neurodevelopment, future study designs must consider absolute and relative availabilities of all LCPUFA species and incorporate the LCPUFA status of both mother and infant in pre- and postnatal periods.

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.

Fatty acids in normal and pathological pregnancies

Long chain fatty acids, namely omega-3 and omega-6, are essential fatty acids and are necessary for proper pregnancy progression and fetal growth and development. Maternal fatty acid consumption and release of fatty acids from lipid stores provide increased availability of fatty acids for the placenta to transport to the growing fetus. Both omega-3 and omega-6 fatty acids are then utilized for generation of signaling molecules, such as eicosanoids, and for promoting of growth and developmental, most notably in the nervous system. Perturbations in fatty acid concentration and fatty acid signaling have been implicated in three major pregnancy complications - gestational diabetes, preeclampsia, and preterm birth. In this review we discuss the growing literature surrounding the role of fatty acids in normal and pathological pregnancies. Differences in maternal, placental, and fetal fatty acids and molecular regulation of fatty acid signaling and transport are presented. A look into novel fatty acid-based therapies for each of the highlighted disorders are discussed, and may present exciting bench to bedside alternatives to traditional pharmacological intervention.

Supplementation of EPA and DHA in pregnant women with type 1 diabetes mellitus

BACKGROUND/OBJECTIVE

Lower proportions of n-3 PUFAs have been observed in neonates born to diabetic mothers. We aimed to investigate the association between DHA and EPA supplementation during pregnancy complicated with type 1 diabetes on concentration and proportion of fatty acids in maternal and foetal blood.

SUBJECTS AND METHODS

We conducted a prospective randomized, single-blinded, placebo-controlled trial of 111 eligible pregnant women with type 1 diabetes and presented the results of 84 (intervention arm and control arm comprised 42 participants each) of them who successfully finished the trial in an academic hospital. The initiation of EPA and DHA supplementation or placebo started at randomization visit on gestational week 11-12. Blood samples were taken on the first (screening) visit to the clinic (1st trimester, between 8th and 10th gestational week, GW), then in the second trimester (19-24th GW) and third trimester (30th-33rd GW). On the delivery day, a blood sample was taken on fasting just before birth. The umbilical vein blood sample was taken shortly after the delivery.

RESULTS

We found a significant increase in the intervention group when compared the first and the third trimester for n-3 PUFAs concentration, 4.3 mg/L (3.3-7.6): 10.0 mg/L (7.1-13.7), p < .001. In the intervention group, the concentration of DHA in maternal vein serum was 11.4 mg/L (7.7-17.5), and in umbilical vein serum, it was 5.1 mg/L (3.0-7.7), which was significantly higher than that in the control group, maternal vein serum: median 9.2 mg/L(6.0-12.3), p = .03 and umbilical vein serum: median 3.4 mg/L (2.1-5.6), p = .009.

CONCLUSION

The increased weight gain in pregnancy and concentration and proportions of DHA, n-3 PUFAs with a decreased proportion of AA, n-6 PUFAs, and AA/DHA ratio in maternal and umbilical vein serum summarize the effect of supplementation with EPA and DHA.

Is Supplementation with Micronutrients Still Necessary during Pregnancy? A Review

INTRODUCTION

Proper nutrition during pregnancy is important to prevent nutritional imbalances that interfere with pregnancy. Micronutrients play critical roles in embryogenesis, fetal growth, and maternal health, as energy, protein, vitamin, and mineral needs can increase during pregnancy. Increased needs can be met by increasing the intake of dietary micronutrients. Severe micronutrient deficiency or excess during pregnancy can have negative effects on fetal growth (intrauterine growth retardation, low birth weight, or congenital malformations) and pregnancy development (pre-eclampsia or gestational diabetes). We investigate whether it is necessary to continue micronutrient supplementation during pregnancy to improve women's health in this stage and whether this supplementation could prevent and control pathologies associated with pregnancy.

AIM

The present review aims to summarize evidence on the effects of nutritional deficiencies on maternal and newborn morbidity.

METHODS

This aim is addressed by critically reviewing results from published studies on supplementation with different nutrients during pregnancy. For this, major scientific databases, scientific texts, and official webpages have been consulted. PubMed searches using the terms "pregnancy" OR "maternal-fetal health" AND "vitamins" OR "minerals" OR "supplementation" AND "requirement" OR "deficiency nutrients" were performed.

RESULTS

There are accepted interventions during pregnancy, such as folic acid supplementation to prevent congenital neural tube defects, potassium iodide supplementation to correct neurodevelopment, and oral iron supplementation during the second half of pregnancy to reduce the risk of maternal anemia and iron deficiency. A number of micronutrients have also been associated with pre-eclampsia, gestational diabetes mellitus, and nausea and vomiting in pregnancy. In general, experimental studies are necessary to demonstrate the benefits of supplementation with different micronutrients and to adjust the recommended daily doses and the recommended periconceptional nutrition for mothers.

CONCLUSIONS

Presently, there is evidence of the benefits of micronutrient supplementation in perinatal results, but indiscriminate use is discouraged due to the fact that the side effects of excessive doses are not known. Evidence supports the idea that micronutrient deficiencies negatively affect maternal health and the outcome of pregnancy. No single micronutrient is responsible for the adverse effects; thus, supplementing or correcting one deficiency will not be very effective while other deficiencies exist.

Long-chain polyunsaturated fatty acid (LC-PUFA) status in severe preeclampsia and preterm birth: a cross sectional study

Long-Chain Polyunsaturated Fatty Acid (LCPUFA) is essential throughout pregnancy, since deficiency of LPUFA may linked to obstetrical complications. This study aimed to investigate LCPUFA status in severe preeclampsia and preterm birth. A cross sectional study was conducted in 104 pregnant women, which divided into normal pregnancy, severe preeclampsia and preterm birth groups. Serum percentage and concentration of total LCPUFA, omega-3, alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), omega-6, linoleic acid (LA), and arachidonic acid (AA) were measured using gas chromatography/mass spectrometry. Receiver operating characteristic (ROC), bivariate and multivariate analysis were performed. Severe preeclampsia showed the highest concentration of total PUFA and the lowest DHA percentage, with significantly higher Omega-6/Omega-3 ratio (p = 0.004) and lower omega-3 index (p < 0.002) compared to control. Preterm birth showed the least omega-3 concentrations, with significantly low omega-6 derivates (LA (p = 0.014) and AA (p = 0.025)) compared to control. LCPUFA parameters have shown to increase the risk in both conditions, particularly ALA ≤ 53 µmol/L in preeclampsia with OR 5.44, 95%CI 1.16-25.42 and preterm birth with OR 4.68, 95%CI 1.52-14.38. These findings suggest that severe preeclampsia and preterm birth have an imbalance in LCPUFA status.

Higher dose docosahexaenoic acid supplementation during pregnancy and early preterm birth: A randomised, double-blind, adaptive-design superiority trial

BACKGROUND

Several meta analyses have concluded n-3 fatty acids, including docosahexaenoic acid (DHA), reduce early preterm birth (EPB, < 34 weeks), however, the amount of DHA required is unclear. We hypothesized that 1000 mg DHA per day would be superior to 200 mg, the amount in most prenatal supplements.

METHODS

This randomised, multicentre, double-blind, adaptive-design, superiority trial was conducted in three USA medical centres. Women with singleton pregnancies and 12 to 20 weeks gestation were eligible. randomization was generated in SAS® by site in blocks of 4. The planned adaptive design periodically generated allocation ratios favoring the better performing dose. Managing study personnel were blind to treatment until 30 days after the last birth. The primary outcome was EPB by dose and by enrolment DHA status (low/high). Bayesian posterior probabilities (pp) were determined for planned efficacy and safety outcomes using intention-to-treat. The study is registered with ClinicalTrials.gov (NCT02626299) and closed to enrolment.

FINDINGS

Eleven hundred participants (1000 mg, n = 576; 200 mg, n = 524) were enrolled between June 8, 2016 and March 13, 2020 with the last birth September 5, 2020. 1032 (n = 540 and n = 492) were included in the primary analyses. The higher dose had a lower EPB rate [1.7% (9/540) vs 2.4% (12/492), pp=0.81] especially if participants had low DHA status at enrolment [2.0% (5/249) vs 4.1%, (9/219), pp=0.93]. Participants with high enrolment DHA status did not realize a dose effect [1000 mg: 1.4% (4/289); 200 mg: 1.1% (3/271), pp = 0.57]. The higher dose was associated with fewer serious adverse events (maternal: chorioamnionitis, premature rupture of membranes and pyelonephritis; neonatal: feeding, genitourinary and neurologic problems, all pp>0.90).

INTERPRETATION

Clinicians could consider prescribing 1000 mg DHA daily during pregnancy to reduce EPB in women with low DHA status if they are able to screen for DHA.

FUNDING

The National Institutes of Health Child Health and Human Development (NICHD) funded the study. Life's DHA™-S oil, DSM Nutritional Products LLC, Switzerland provided all capsules.

Supplementation of Omega 3 during Pregnancy and the Risk of Preterm Birth: A Systematic Review and Meta-Analysis

Preterm birth (PTB) is a major cause of neonatal death and long-term consequences for the newborn. This review aims to update the evidence about the potential benefit of pharmacological supplementation with omega 3 fatty acids during pregnancy on the incidence of PTB. The Medline, Embase, Cochrane Library and Central databases were searched until 28 June 2020 for RCTs in which omega 3 supplementation was used versus placebo to reduce PTB risk. Data from 37 trials were analyzed. We found an 11% reduction in PTB risk (RR(risk ratios), 0.89; 95% CI (confidence intervals), 0.82 to 0.97) in trials using omega 3 supplements versus placebo. Regarding early PTB (ePTB), there was a 27% reduction in the risk of ePTB (RR, 0.73; 95% CI, 0.58 to 0.92). However, after sensitivity analyses, there were no significant differences in PTB and ePTB risk (PTB RR, 0.92; 95% CI, 0.83 to 1.01, ePTB RR, 0.82; 95% CI, 0.61 to 1.09). We conclude that omega 3 supplementation during pregnancy does not reduce the risk of PTB and ePTB. More studies are required to determine the effect of omega 3 supplementations during pregnancy and the risk of detrimental fetal outcomes.

Plasma long-chain omega-3 fatty acid status and risk of recurrent early spontaneous preterm birth: a prospective observational study

INTRODUCTION

A 2018 Cochrane review found that omega-3 supplementation in pregnancy was associated with a risk reduction of early preterm birth of 0.58; prompting calls for universal supplementation. Recent analysis suggests the benefit may be confined to women with a low baseline omega-3 fatty acid status. However, the contemporary omega-3 fatty acid status of pregnant women in the UK is largely unknown. This is particularly pertinent for women with a previous preterm birth, in whom a small relative risk reduction would have a larger reduction of absolute risk. This study aimed to assess the omega-3 fatty acid status of a UK pregnant population and determine the association between the long-chain omega-3 fatty acids and recurrent spontaneous early preterm birth.

MATERIAL AND METHODS

A total of 283 high-risk women with previous early preterm birth were recruited to the prospective observational study in Liverpool, UK. Additionally, 96 pregnant women with previous term births and birth ≥39⁺⁰  weeks in the index pregnancy provided a low-risk population sample. Within the high-risk group we assessed the odds ratio of recurrent early preterm birth compared with birth at ≥37⁺⁰  weeks of gestation according to plasma eicosapentaenoic acid plus docosahexaenoic acid (EPA+DHA) at 15-22 weeks of gestation.

RESULTS

Our participants had low EPA+DHA; 62% (143/229) of women with previous preterm birth and 69% (68/96) of the population sample had levels within the lowest two quintiles of a previously published pregnancy cohort. We found no association between long-chain omega-3 status and recurrent early preterm birth (n = 51). The crude odds ratio of a recurrent event was 0.91 (95% CI 0.38-2.15, p = 0.83) for women in the lowest, compared with the highest three quintiles of EPA+DHA.

CONCLUSIONS

In the majority of our participants, levels of long-chain omega-3 were low; within the range that may benefit from supplementation. However, levels showed no association with risk of recurrent early spontaneous preterm birth. This could be because our population levels were too low to show benefit in being omega-3 "replete"; or else omega-3 levels may be of lesser importance in recurrent early preterm birth.

Perinatal Dietary Polyunsaturated Fatty Acids in Brain Development, Role in Neurodevelopmental Disorders

n-3 and n-6 polyunsaturated fatty acids (PUFAs) are essential fatty acids that are provided by dietary intake. Growing evidence suggests that n-3 and n-6 PUFAs are paramount for brain functions. They constitute crucial elements of cellular membranes, especially in the brain. They are the precursors of several metabolites with different effects on inflammation and neuron outgrowth. Overall, long-chain PUFAs accumulate in the offspring brain during the embryonic and post-natal periods. In this review, we discuss how they accumulate in the developing brain, considering the maternal dietary supply, the polymorphisms of genes involved in their metabolism, and the differences linked to gender. We also report the mechanisms linking their bioavailability in the developing brain, their transfer from the mother to the embryo through the placenta, and their role in brain development. In addition, data on the potential role of altered bioavailability of long-chain n-3 PUFAs in the etiologies of neurodevelopmental diseases, such as autism, attention deficit and hyperactivity disorder, and schizophrenia, are reviewed.

Plasma oxylipin levels associated with preterm birth in preterm labor✰

INTRODUCTION

Preterm labor is a common clinical problem in obstetrics. Since the majority of women with preterm labor eventually deliver at full term, biomarkers are needed to more accurately predict who will deliver preterm. Oxylipins, given their importance in inflammation regulation, are highly interesting in this respect since labor is an inflammatory process.

METHODS

Eighty women with preterm labor before 34 weeks of gestation were enrolled in a prospective observational multi-center cohort study. Oxylipin levels of 67 analytes in plasma samples were analyzed by liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Twenty-one (26%) of the women delivered before 34 weeks of gestation, and of those women, fourteen delivered within 48 h of admission. Logistic multivariate regression showed that lower levels of 9,10-DiHODE were associated with delivery before 34 weeks of gestation (aOR 0.12 (0.024-0.62)) and within 48 h ((aOR 0.13 (0.019-0.93)). Furthermore, higher levels of 11,12-DiHETrE were associated with delivery before 34 weeks of gestation ((aOR 6.19 (1.17-32.7)) and higher levels of 8-HETE were associated with delivery within 48 h ((aOR 5.01 (1.13-22.14)).

CONCLUSIONS

The oxylipin 9,10-DiHODE may be protective in preterm labor, both for delivery after 34 weeks of gestation and for delivery later than 48 h of admission, whereas 11,12-DiHETrE and 8-HETE display the opposite effect. Larger studies are needed to validate these mediators as biomarkers for prediction of preterm birth following preterm labor.

Prenatal Nutritional Strategies to Reduce the Risk of Preterm Birth

Worldwide, around 15 million preterm babies are born annually, and despite intensive research, the specific mechanisms triggering preterm birth (PTB) remain unclear. Cost-effective primary prevention strategies to reduce PTB are required, and nutritional interventions offer a promising alternative. Nutrients contribute to a variety of mechanisms that are potentially important to preterm delivery, such as infection, inflammation, oxidative stress, and muscle contractility. Several observational studies have explored the association between dietary nutrients and/or dietary patterns and PTB, often with contrasting results. Randomized trial evidence on the effects of supplementation with zinc, multiple micronutrients (iron and folic acid), and vitamin D is promising; however, results are inconsistent, and many studies are not adequately powered for outcomes of PTB. Large-scale clinical trials with PTB as the primary outcome are needed before any firm conclusions can be drawn for these nutrients. The strongest evidence to date for a nutritional solution exists for omega-3 long-chain polyunsaturated fatty acids (LCPUFAs), key nutrients in fish. In 2018, a Cochrane Review (including 70 studies) showed that prenatal supplementation with omega-3 LCPUFAs reduced the risk of PTB and early PTB (EPTB) compared with no omega-3 supplementation. However, the largest trial of omega-3 supplementation in pregnancy, the Omega-3 to Reduce the Incidence of Prematurity (ORIP) trial (n = 5,544), showed no reduction in EPTB and a reduction in PTB only in a prespecified analysis of singleton pregnancies. Exploratory analyses from the ORIP trial found that women with low baseline total omega-3 status were at higher risk of EPTB, and that this risk was substantially reduced with omega-3 supplementation. In contrast, women with replete or high baseline total omega-3 status were already at low risk of EPTB and additional omega-3 supplementation increased the risk of EPTB compared to control. These findings suggest that determining an individual woman's PUFA status may be the most precise way to inform recommendations to reduce her risk of PTB.

Exploring the role of LC-PUFA metabolism in pregnancy complications

Maternal nutrition during pregnancy plays a significant role in growth and development of the placenta and influencing pregnancy outcome. Suboptimal nutritional status during early gestational period compromises the normal course of pregnancy leading to adverse maternal and fetal outcomes. Omega-3 and omega-6 long chain polyunsaturated fatty acids (LC-PUFA) are important for the growth and development of the placenta. Maternal fatty acids and their metabolites influence the normal course of pregnancy by regulating cell growth and development, cell signaling, regulate angiogenesis, modulate inflammatory responses and influence various structural and functional processes. Alterations in LC-PUFA and their metabolites may result in inadequate spiral artery remodeling or placental angiogenesis leading to structural and functional deficiency of the placenta which contributes to several pregnancy complications like preeclampsia, gestational diabetes mellitus, intrauterine growth restriction, and results in adverse birth outcomes. In this review, we summarize studies examining the role of fatty acids and their metabolites in pregnancy. We also discuss the possible molecular mechanisms through which LC-PUFA influences placental growth and development. Studies have demonstrated that omega-3 fatty acid supplementation lowers the incidence of preterm births, but its effect on reducing pregnancy complications are inconclusive.

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.

Controversies in the prevention of spontaneous preterm birth in asymptomatic women: an evidence summary and expert opinion

Preterm birth prevention is multifaceted and produces many nuanced questions. This review addresses six important clinical questions about preterm birth prevention as voted for by members of the UK Preterm Clinical Network. The questions cover the following areas: preterm birth prevention in 'low-risk' populations; screening for asymptomatic genital tract infection in women at high risk of preterm birth; cervical length screening with cerclage or vaginal pessary in situ; cervical shortening whilst using progesterone; use of vaginal progesterone in combination with cervical cerclage; and optimal advice about intercourse for women at high risk of preterm birth.

Maternal Long-Chain Polyunsaturated Fatty Acid Status, Methylmercury Exposure, and Birth Outcomes in a High-Fish-Eating Mother-Child Cohort

BACKGROUND

Maternal status of long-chain PUFAs (LC-PUFAs) may be related to fetal growth. Maternal fish consumption exposes the mother to the neurotoxicant methylmercury (MeHg), which, in contrast, may restrict fetal growth.

OBJECTIVE

Our aim was to examine relations between maternal LC-PUFA status at 28 wk and birth outcomes (birth weight, length, and head circumference), controlling for MeHg exposure throughout pregnancy, in the Seychelles Child Development Study Nutrition Cohort 2. Our secondary aim was to examine the influence of maternal variation in genes regulating the desaturation of LC-PUFAs [fatty acid desaturase (FADS)] on birth outcomes.

METHODS

From nonfasting blood samples collected at 28 wk of gestation, we measured serum total LC-PUFA concentrations and FADS1 (rs174537, rs174561), FADS1-FADS2rs3834458, and FADS2rs174575 genotypes, with hair total mercury concentrations assessed at delivery. Data were available for n = 1236 mother-child pairs. Associations of maternal LC-PUFAs, MeHg, and FADS genotype with birth outcomes were assessed by multiple linear regression models, adjusting for child sex, gestational age, maternal age, BMI, alcohol use, socioeconomic status, and parity.

RESULTS

In our cohort of healthy mothers, neither maternal LC-PUFA status nor MeHg exposure were significant determinants of birth outcomes. However, when compared with major allele homozygotes, mothers who were heterozygous for the minor allele of FADS1 (rs174537 and rs174561, GT compared with TT, β = 0.205, P = 0.03; TC compared with CC, β = 0.203, P = 0.04) and FADS1-FADS2 (rs3834458, Tdel compared with DelDel, β = 0.197, P = 0.04) had infants with a greater head circumference (all P < 0.05). Homozygosity for the minor allele of FADS2 (rs174575) was associated with a greater birth weight (GG compared with CC, β = 0.109, P = 0.04).

CONCLUSIONS

In our mother-child cohort, neither maternal LC-PUFA status nor MeHg exposure was associated with birth outcomes. The observed associations of variation in maternal FADS genotype with birth outcomes should be confirmed in other populations.

Omega-3 index in 2018/19

The omega-3 index, the percentage of EPA plus DHA in erythrocytes (measured by standardised analysis), represents a human body's status in EPA and DHA. An omega-3 index is measured in many laboratories around the world; however, even small differences in analytical methods entail large differences in results. Nevertheless, results are frequently related to the target range of 8-11 %, defined for the original and scientifically validated method (HS-Omega-3 Index®), raising ethical issues, and calling for standardisation. No human subject has an omega-3 index <2 %, indicating a vital minimum. Thus, the absence of EPA and DHA cannot be tested against presence. Moreover, clinical events correlate with levels, less with the dose of EPA and DHA, and the bioavailability of EPA and DHA varies inter-individually. Therefore, the effects of EPA and DHA are difficult to demonstrate using typical drug trial methods. Recent epidemiologic data further support the relevance of the omega-3 index in the cardiovascular field, since total mortality, cardiovascular mortality, cardiovascular events such as myocardial infarction or stroke, or blood pressure all correlate inversely with the omega-3 index. The omega-3 index directly correlates with complex brain functions. Compiling recent data supports the target range for the omega-3 index of 8-11 % in pregnancy. Many other potential applications have emerged. Some, but not all health issues mentioned have already been demonstrated to be improved by increasing intake of EPA and DHA. Increasing the omega-3 index into the target range of 8-11 % with individualised doses of toxin-free sources for EPA and DHA is tolerable and safe.

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.

Omega-3 fatty acid supplementation in pregnancy-baseline omega-3 status and early preterm birth: exploratory analysis of a randomised controlled trial

OBJECTIVE

To identify a polyunsaturated fatty acid (PUFA) biomarker able to detect which women with singleton pregnancies are most likely to benefit from omega-3 supplementation to reduce their risk of early preterm birth.

DESIGN

Exploratory analysis of a randomised controlled trial.

SETTING

Six Australian hospitals.

POPULATION

Women with a singleton pregnancy enrolled in the ORIP trial.

METHODS

Using maternal capillary whole blood collected ~14 weeks' gestation, the fatty acids in total blood lipids were quantified using gas chromatography. Interaction tests examined whether baseline PUFA status modified the effect of omega-3 supplementation on birth outcomes.

MAIN OUTCOME MEASURE

Early preterm birth (<34 weeks' gestation).

RESULTS

A low total omega-3 PUFA status in early pregnancy was associated with a higher risk of early preterm birth. Among women with a total omega-3 status ≤4.1% of total fatty acids, omega-3 supplementation substantially reduced the risk of early preterm birth compared with control (0.73 versus 3.16%; relative risk = 0.23, 95% confidence interval [CI] 0.07-0.79). Conversely, women with higher total omega-3 status in early pregnancy were at lower risk of early preterm birth. Supplementing women with a baseline status above 4.9% increased early preterm birth (2.20 versus 0.97%; relative risk = 2.27, 95% CI 1.13-4.58).

CONCLUSIONS

Women with singleton pregnancies and low total omega-3 PUFA status early in pregnancy have an increased risk of early preterm birth and are most likely to benefit from omega-3 supplementation to reduce this risk. Women with higher total omega-3 status are at lower risk and additional omega-3 supplementation may increase their risk.

TWEETABLE ABSTRACT

Low total omega-3 fat status helps identify which women benefit from extra omega-3 to reduce early prematurity.

Impact of erythrocyte long-chain omega-3 polyunsaturated fatty acid levels in early pregnancy on birth outcomes: findings from a Belgian cohort study

OBJECTIVE

To examine the association between maternal erythrocyte long-chain omega-3 PUFA (n-3 LCPUFA), measured in early pregnancy, and pregnancy and birth outcomes.

STUDY DESIGN

One hundred and eight healthy women with a singleton pregnancy were included. Erythrocyte fatty acids were analyzed using gas chromatography. Gestational length, birth anthropometric measures, and pregnancy-associated complications were collected from hospital medical records.

RESULTS

We observed significant positive associations between maternal docosahexaenoic acid (DHA) levels (p = 0.024) and omega-3 index values (p = 0.021) and gestational length in adjusted linear regression models. Each point in maternal DHA level was associated with 2.19 days longer gestational duration (β = 2.19; 95% CI 0.29-4.09). No consistent associations were found between n-3 PUFA levels and composite pregnancy outcome.

CONCLUSION

These findings suggest that the gestational length is positively affected by maternal n-3 LCPUFA status as soon as the early stages of pregnancy.

Can human nutrition be improved through better fish feeding practices? a review paper

Achieving Sustainable Development Goal 2 of zero hunger and malnutrition by 2030 will require dietary shifts that include increasing the consumption of nutrient dense foods by populations in low- and middle-income countries. Animal source foods are known to be rich in a number of highly bioavailable nutrients that otherwise are not often consumed in the staple-food based diets of poorer populations throughout the world. Fish is the dominant animal source food in many low- and middle-income countries in the global south and is available from both fisheries and aquaculture. Consumers often perceive that wild caught fish have higher nutritional value than fish produced through aquaculture, and this may be true for some nutrients, for example omega-3 fatty acid content. However, there is potential to modify the nutritional value of farmed fish through feeds and through production systems, illustrated by the common practice of supplementing omega-3 fatty acids in fish diets to optimize their fatty acid profile. This manuscript reviews the evidence related to fish feeds and the nutritional composition of fish with respect to a number of nutrients of interest to human health, including iron, zinc, vitamins A and D, selenium, calcium, and omega-3 fatty acids, with low- and middle-income country populations in mind. In general, we find that the research on fortification of fish diet particularly with vitamins and minerals has not been directed toward human health but rather toward improvement of fish growth and health performance. We were unable to identify any studies directly exploring the impact of fish feed modification on the health of human consumers of fish, but as nutrition and health rises in the development agenda and consumer attention, the topic requires more urgent attention in future feed formulations.

[Confusion about the effects of omega-3 fatty acids : Contemplation of study data taking the omega-3 index into consideration]

BACKGROUND

Confusion reigns about omega‑3 fatty acids and their effects. Scientific investigations did not appear to clarify the issue. Guidelines and regulatory authorities contradict each other.

OBJECTIVE

This article provides clarity by considering not intake but levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocytes as a percentage of all fatty acids measured (omega‑3 index).

CURRENT DATA

The largest database of all methods of fatty acid analyses has been generated with the standardized HS-Omega‑3 Index® (Omegametrix, Martinsried, Deutschland). The omega‑3 index assesses the in EPA+DHA status of a person, has a minimum of 2%, a maximum of 20%, and is optimal between 8% and 11%. In many western countries but not in Japan or South Korea, mean levels are suboptimal. Suboptimal levels correlate with increased total mortality, sudden cardiac death, fatal and non-fatal myocardial infarction, other cardiovascular diseases, cognitive impairment, major depression, premature birth and other health issues. Interventional studies on surrogate and intermediary parameters demonstrated many positive effects, correlating with the omega‑3 index when measured. Due to issues in methodology that became apparent from the perspective of the omega‑3 index many, even large interventional trials with clinical endpoints were not positive, which is reflected in pertinent meta-analyses. In contrast, interventional trials without issues in methodology the clinical endpoints mentioned were reduced.

CONCLUSION

All humans have levels of EPA+DHA that if methodologically correctly assessed in erythrocytes, are optimal between 8% and 11%. Deficits can cause serious health issues that can be prevented by optimal levels.

Nutritional Gaps and Supplementation in the First 1000 Days

Optimized nutrition during the first 1000 days (from conception through the 2nd birthday) is critical for healthy development and a healthy life for the newborn. Pregnancy and the postpartum period are accompanied by physiological changes, increased energy needs, and changing requirements in the nutrients critical for optimal growth and development. Infants and toddlers also experience physiological changes and have specific nutritional needs. Food and nutrition experts can provide women of childbearing age with adequate dietary advice to optimize nutrition, as well as guidance on selecting appropriate dietary supplements. Considering the approaching 2020-2025 Dietary Guidelines for Americans (DGA) will be making specific recommendations for children, it is important to provide accurate scientific information to support health influencers in the field of nutrition. The purpose of this review is to summarize the nutrition and supplementation literature for the first 1000 days; to highlight nutritional and knowledge gaps; and to educate nutrition influencers to provide thoughtful guidance to mothers and families. Optimal nutrition during pregnancy through early childhood is critical for supporting a healthy life. Nutrition influencers, such as dietitians, obstetricians/gynecologists, and other relevant health professionals, should continue guiding supplement and food intake and work closely with expectant families and nutrition gatekeepers.

The role of long chain polyunsaturated fatty acids in perinatal nutrition

The importance of omega-3 long chain polyunsaturated fatty acids in the perinatal period has been the focus of research for several decades. Infants born preterm miss out on the last trimester in utero transfer of omega-3 fatty acids and consequently have lower blood levels than infants born at term. Preterm infant formula was supplemented with the omega-3 docosahexaenoic acid and the omega-6 arachidonic acid from 2000 (to the level found in the breast milk of women consuming a western diet) based on trials reporting improvements in visual acuity. Docosahexaenoic acid supplementation beyond this level has not shown improvements in clinical or developmental outcomes, however the effect on childhood development in the most preterm infants remains to be resolved. Maternal omega-3 supplementation during pregnancy has the potential to reduce the incidence of preterm birth but may also, in some pregnancies, prolong gestation beyond term and increase fetal size.

A Randomized Trial of Prenatal n-3 Fatty Acid Supplementation and Preterm Delivery

BACKGROUND

Previous studies have suggested that maternal supplementation with n-3 long-chain polyunsaturated fatty acids may reduce the incidence of preterm delivery but may also prolong gestation beyond term; however, more data are needed regarding the role of n-3 long-chain polyunsaturated fatty acids in pregnancy.

METHODS

We performed a multicenter, double-blind, randomized trial in which women who were pregnant with single or multiple fetuses were assigned to receive either fish-oil capsules that contained 900 mg of n-3 long-chain polyunsaturated fatty acids (n-3 group) or vegetable-oil capsules that contained trace n-3 long-chain polyunsaturated fatty acids (control group) daily, beginning before 20 weeks of gestation and continuing to 34 weeks of gestation or delivery, whichever occurred first. The primary outcome was early preterm delivery, defined as delivery before 34 completed weeks of gestation. Other pregnancy and neonatal outcomes were also assessed.

RESULTS

A total of 5544 pregnancies in 5517 women were randomly assigned at six centers in Australia; 5486 pregnancies were included in the primary analysis. Early preterm delivery occurred in the case of 61 of 2734 pregnancies (2.2%) in the n-3 group and 55 of 2752 pregnancies (2.0%) in the control group; the between-group difference was not significant (adjusted relative risk, 1.13; 95% confidence interval [CI], 0.79 to 1.63; P = 0.50). There were no significant differences between the groups in the incidence of interventions in post-term (>41 weeks of gestation) deliveries, in adverse events, or in other pregnancy or neonatal outcomes, except that a higher percentage of infants born to women in the n-3 group than in the control group were very large for gestational age at birth (adjusted relative risk, 1.30; 95% CI, 1.02 to 1.65). Percentages of serious adverse events did not differ between the groups. Minor gastrointestinal disturbances were more commonly reported in the n-3 group than in the control group.

CONCLUSIONS

Supplementation with n-3 long-chain polyunsaturated fatty acids from early pregnancy (<20 weeks of gestation) until 34 weeks of gestation did not result in a lower incidence of early preterm delivery or a higher incidence of interventions in post-term deliveries than control. (Funded by the Australian National Health and Medical Research Council and the Thyne Reid Foundation; ORIP Australian New Zealand Clinical Trials Registry number, ACTRN12613001142729.).

Screening for Preterm Birth: Potential for a Metabolomics Biomarker Panel

The aim of this preliminary study was to investigate the potential of maternal serum to provide metabolomic biomarker candidates for the prediction of spontaneous preterm birth (SPTB) in asymptomatic pregnant women at 15 and/or 20 weeks’ gestation. Metabolomics LC-MS datasets from serum samples at 15- and 20-weeks’ gestation from a cohort of approximately 50 cases (GA < 37 weeks) and 55 controls (GA > 41weeks) were analysed for candidate biomarkers predictive of SPTB. Lists of the top ranked candidate biomarkers from both multivariate and univariate analyses were produced. At the 20 weeks’ GA time-point these lists had high concordance with each other (85%). A subset of 4 of these features produce a biomarker panel that predicts SPTB with a partial Area Under the Curve (pAUC) of 12.2, a sensitivity of 87.8%, a specificity of 57.7% and a p-value of 0.0013 upon 10-fold cross validation using PanelomiX software. This biomarker panel contained mostly features from groups already associated in the literature with preterm birth and consisted of 4 features from the biological groups of “Bile Acids”, “Prostaglandins”, “Vitamin D and derivatives” and “Fatty Acids and Conjugates”.

Omega-3 polyunsaturated fatty acid intake norms and preterm birth rate: a cross-sectional analysis of 184 countries

BACKGROUND

The preponderance of evidence now indicates that elevated long-chain omega-3 polyunsaturated fatty acid (LC omega-3 PUFA) intake is often associated with reduced risk of preterm birth (PTB). This conclusion is based on recent meta-analyses that include several studies that reported null findings. We probed the reasons for this heterogeneity across studies and its implications for PTB prevention using country-level data.

METHODS

We analysed the relationship between national PTB rates (<37 weeks of gestation) and omega-3 PUFA intake norms from 184 countries for the year 2010. To estimate the total LC omega-3 PUFA levels (eicosapentaenoic acid [EPA]/docosahexaenoic acid [DHA]) that these norms produce we utilised a metric that accounts for (1) seafood-based omega-3 intake (EPA/DHA) and (2) plant-based omega-3 intake (alpha-linolenic acid [ALA]), ~20% of which is converted to EPA/DHA in vivo. We then assessed the shape of the omega-3-PTB relationship with a penalised spline and conducted linear regression analyses within the linear sections of the relationship.

RESULTS

Penalised spline analyses indicated that PTB rates decrease linearly with increasing omega-3 levels up to ~600 mg/day. Income-adjusted linear regression analysis among the countries in this exposure range indicated that the number of PTBs per 100 live births decreases by 1.5 (95% CI 2.8 to 0.3) for each 1 SD increase in omega-3 intake norms (383 mg/day).

CONCLUSIONS

Taken with prior evidence for a causal association on the individual level, our findings indicate that omega-3 PUFA deficiency may be a widespread contributing factor in PTB risk. Consideration of baseline omega-3 PUFA levels is critical in the design of future interventions.

The Effects of Vegetarian and Vegan Diet during Pregnancy on the Health of Mothers and Offspring

Vegetarian and vegan diets have increased worldwide in the last decades, according to the knowledge that they might prevent coronary heart disease, cancer, and type 2 diabetes. Althought plant-based diets are at risk of nutritional deficiencies such as proteins, iron, vitamin D, calcium, iodine, omega-3, and vitamin B12, the available evidence shows that well planned vegetarian and vegan diets may be considered safe during pregnancy and lactation, but they require a strong awareness for a balanced intake of key nutrients. A review of the scientific literature in this field was performed, focusing specifically on observational studies in humans, in order to investigate protective effects elicited by maternal diets enriched in plant-derived foods and possible unfavorable outcomes related to micronutrients deficiencies and their impact on fetal development. A design of pregestational nutrition intervention is required in order to avoid maternal undernutrition and consequent impaired fetal growth.

Comparisons of Estimated Intakes and Plasma Concentrations of Selected Fatty Acids in Pregnancy

The growing interest in potential health effects of long-chain polyunsaturated fatty acids (PUFAs) makes it important to evaluate the method used to assess the fatty acid intake in nutrition research studies. We aimed to validate the questionnaire-based dietary intake of selected PUFAs: eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), α-linolenic acid (ALA), linoleic acid (LA), and arachidonic acid (AA) within the Danish National Birth Cohort (DNBC), by comparing 345 women’s reported intake with concentration of plasma biomarkers. The applied questionnaire- and biomarker data reflect dietary intake from around the same time point in mid-pregnancy and relationships were investigated by use of Pearson and Spearman correlation and linear regression statistics. We demonstrated moderate but consistent adjusted correlations between dietary intake estimates and the corresponding plasma biomarker concentrations (differences in plasma concentration per 100 mg/day greater intake of 0.05 (95% CI: 0.02; 0.08)) and 0.05 (95% CI: 0.01; 0.08) percentage of total plasma fatty acids for EPA and DHA, respectively). The associations strengthened when restricting the analyses to women with ALA intake below the median intake. We found a weak correlation between the dietary intake of ALA and its plasma biomarker with a difference in plasma concentration of 0.07 (95% CI: 0.03; 0.10) percent of total plasma fatty acids per 1 g/day greater intake, while the dietary intake of LA and AA did not correlate with their corresponding biomarkers.

A More Comprehensive Approach to the Neuroprotective Potential of Long-Chain Polyunsaturated Fatty Acids in Preterm Infants Is Needed-Should We Consider Maternal Diet and the n-6:n-3 Fatty Acid Ratio?

There is growing evidence that long-chain polyunsaturated fatty acids (LCPUFAs) are of importance for normal brain development. Adequate supply of LCPUFAs may be particularly important for preterm infants, because the third trimester is an important period of brain growth and accumulation of arachidonic acid (n-6 LCPUFA) and docosahexaenoic acid (n-3 LCPUFA). Fatty acids from the n-6 and n-3 series, particularly, have important functions in the brain as well as in the immune system, and their absolute and relative intakes may alter both the risk of impaired neurodevelopment and response to injury. This narrative review focuses on the potential importance of the n-6:n-3 fatty acid ratio in preterm brain development. Randomized trials of post-natal LCPUFA supplementation in preterm infants are presented. Pre-clinical evidence, results from observational studies in preterm infants as well as studies in term infants and evidence related to maternal diet during pregnancy, focusing on the n-6:n-3 fatty acid ratio, are also summarized. Two randomized trials in preterm infants have compared different ratios of arachidonic acid and docosahexaenoic acid intakes. Most of the other studies in preterm infants have compared formula supplemented with arachidonic acid and docosahexaenoic acid to un-supplemented formula. No trial has had a comprehensive approach to differences in total intake of both n-6 and n-3 fatty acids during a longer period of neurodevelopment. The results from preclinical and clinical studies indicate that intake of LCPUFAs during pregnancy and post-natal development is of importance for neurodevelopment and neuroprotection in preterm infants, but the interplay between fatty acids and their metabolites is complex. The best clinical approach to LCPUFA supplementation and n-6 to n-3 fatty acid ratio is still far from evident, and requires in-depth future studies that investigate specific fatty acid supplementation in the context of other fatty acids in the diet.

A Prenatal DHA Test to Help Identify Women at Increased Risk for Early Preterm Birth: A Proposal

Fish intake and docosahexaenoic acid (DHA), a nutrient found in fish, have been favorably linked to several pregnancy outcomes. The risk of early preterm birth (ePT, <34 weeks gestation) is associated with low fish intake and DHA blood levels and can be reduced by supplemental DHA. Here, we summarize the evidence linking blood DHA levels with risk for ePT birth, and based on the available studies, propose that women who are pregnant or trying to become pregnant aim for a red blood cell (RBC) DHA value of at least 5% (of total RBC fatty acids). In the US, ~70% of women of childbearing age are likely below this cut-point, and dietary intake data suggest that this group, including pregnant women, consumes ~60 mg/day DHA and that >90% of this group do not take an omega-3 supplement. Since the recommendations for women to consume fish and to take a 200 mg DHA supplement during pregnancy are not being heeded generally, there is a need to motivate practitioners and pregnant women to attend to these recommendations. Having an objective prenatal blood DHA test could provide such motivation. More research is needed to test the clinical utility of this proposed target prenatal DHA level.