High-DHA eggs: feasibility as a means to enhance circulating DHA in mother and infant

Impact of n-3 polyunsaturated fatty acid intake in pregnancy on maternal health and birth outcomes: systematic review and meta-analysis from randomized controlled trails

BACKGROUND

Maternal omega-3 consumption during pregnancy has been positively linked with a positive impact on maternal health and fetal growth. However, the results of individual studies are inconsistent and conflicting.

OBJECTIVE

Examine the effect of supplementation with DHA, and/or EPA, and/or ALA throughout pregnancy on offspring's growth and pregnancy outcomes.

DESIGN

A systematic review and meta-analysis.

POPULATION

Pregnant women.

METHODS

According to (PRISMA) statement and the Cochrane Handbook guidelines. Human trials (RCT or quasi-RCT) which involved oral omega-3 supplementation at least twice a week during pregnancy were included and comparing it with control groups with no supplementation or placebo administration. Data were extracted and directed using RevMan software. Fifty-nine randomized controlled trials were eligible for inclusion in the meta-analysis. Performed in MEDLINE, PubMed, Scopus, Google Scholar, and the Cochrane Library comparing omega 3 with control groups, from 1990 to 2020.

THE MAIN OUTCOME MEASURES

The primary outcome measures were pregnancy-induced hypertension, preeclampsia, gestational duration, preterm birth, early preterm birth, birth weight, low birth weight, neonatal length, and head circumference. The secondary outcomes were neonatal intensive care unit, infant death, prenatal death, and cesarean section.

RESULTS

In 24 comparisons (21,919 women) n-3 fatty acids played a protective role against the risk of preeclampsia (RR = 0.84, 95% CI 0.74-0.96 p = 0.008; I² = 24%). In 46 comparisons (16,254 women) n-3 fatty acids were associated with a significantly greater duration of pregnancy (MD = 1.35, 95% CI 0.65-2.05, p = 0.0002; I² = 59%). 27 comparisons (15,510 women) was accompanied by a significant decrease in pre-term birth less than 37 weeks (RR = 0.86, 95% CI 0.77-0.95, p = 0.005; I² = 0%). 12 comparisons (11,774 women) was accompanied by a significant decrease in early pre-term birth less than 34 weeks (RR = 0.77, 95% CI 0.63-0.95, p = 0.01; I² = 40%). 38 comparisons (16,505 infants) had a significant increase in birth weight (MD = 49.19, 95% CI 28.47-69.91, p < 0.00001; I² = 100%). Finally, 14 comparisons (8,449 infants) had a borderline significance in increase in low birth weight (RR = 0.88, 95% CI 0.78-1.00, p = 0.05; I² = 28%).

CONCLUSIONS

Supplementation with omega-3 in prgnancy can prevent preeclampsia, increase gestational duration, increase birth weight and decrease the risk of low birth weight and preterm birth.

Does trans fatty acid affect low birth weight? A randomised controlled trial

To evaluate the effect of low trans fatty acids (TFAs) dietary patterns during pregnancy on the risk of low birth weight (LBW). All pregnant women who received prenatal care with gestational age <8 weeks in this study took place in Tehran from December 2014 to August 2016. Women in the intervention group received dietary patterns with TFAs content of < 1%; those in the control group had dietary intake without any change in TFAs content. Dietary intakes were assessed by 3 non-consecutive 24-hour recalls in three trimesters. Hazard ratio (HR) was calculated using Cox proportional-hazards models. Incidence and HR (95% CI) for LBW based on multivariable adjusted models were calculated. Of the 800 women (n = 407 in control and n = 393 in intervention groups), 108 (13.5%) women were diagnosed with LBW. The incidence of LBW in the intervention group was 12% and in the control group was 19%. After multivariable adjustment for confounders, the HR for incident LBW in the intervention group was 0.65 (0.44-0.96). Kaplan-Meier plot showed a significant difference between the two groups in the incidence of LBW. Intake of low TFAs dietary patterns during pregnancy reduced the risk of LBW. IMPACT STATEMENTWhat is already known on this subject? Maternal nutrition affects foetal development, and one important dietary determinant of foetal growth may be trans fatty acids (TFAs). It is generally advised to avoid high-fat dairy products that are the main sources of TFAs during pregnancy; however, there is limited data on the effects of a diet of LBW.What do the results of this study add? Intake of low TFAs dietary patterns during pregnancy reduced the risk of LBW. In this study, the risk of LBW in the intervention group decreased by about 50%.What are the implications of these findings for clinical practice and/or further research? The results of this study could give physicians and other health care providers the hint that Management of maternal nutrition with focussed on TFAs content should be included in routine prenatal care, to facilitate interventions and guidance regarding maternal nutrition.

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.

Systematic Literature Review and Meta-Analysis of the Relationship Between Polyunsaturated and Trans Fatty Acids During Pregnancy and Offspring Weight Development

Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and trans fatty acids (TFAs) may have an impact on offspring weight development. We conducted a systematic review and meta-analysis according to PRISMA guidelines to evaluate whether levels of these fatty acids during pregnancy influenced offspring weight development. Randomized controlled trials (RCTs) with DHA and/or EPA supplementation or cohort studies, which examined levels of DHA, EPA, or TFAs in maternal or neonatal blood samples and recorded offspring weight, were included. Overall, 27 RCTs and 14 observational studies were identified. The results showed that DHA and/or EPA supplementation doses >650 mg/day resulted in slightly higher birth weight (MD 87.5 g, 95% CI 52.3-122.6, n = 3,831) and combined BMI and BMI z score at 5-10 years (SMD 0.11, 95% CI 0.04-0.18, n = 3,220). These results were rated as moderate quality. Results from the observational studies were generally inconsistent. High TFA levels during pregnancy seemed to be associated with lower birth weight. Finally, this review and meta-analysis supports a relationship between high maternal or neonatal DHA and/or EPA levels and higher offspring birth weight and weight in childhood. More high-quality long-term studies are still needed.

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).

Neurodevelopmental outcome at 1 year in offspring of women with gestational diabetes mellitus

OBJECTIVE

To study the metabolic derangements in the second half of pregnancy caused by gestational diabetes mellitus(GDM), on the short term neurodevelopment of infants.

DESIGN

A prospective cohort study of 555 mother-child pairs were recruited, which included 177 GDM patients and 378 pregnant women with normal glucose tolerance as controls. Clinical and demographic characteristics were obtained at enrollment, birth and follow-up. Neurodevelopment was examined with the Bayley Scales of Infant Development V.1 mental development index (MDI) and psychomotor development index (PDI). Fatty acids (FA) were analyzed by gas chromatography mass spectrometry (GC-MS).

RESULTS

Statistically significant differences were found between the two groups in fasting plasma glucose (FPG) and triglyceride (TG). The scores of MDI and PDI of control group were higher than those of GDM group. The regression analysis showed that maternal age and saturated fatty acid (SFA) were independently associated with lower scores on the MDI whereas gestational age and docosahexaenoic acid (DHA) were associated with higher scores; in addition, lower scores on the PDI were associated with FPG and neonatal weigh associated with higher scores.

CONCLUSION

SFA, DHA and FPG as indicators of lipid metabolism were associated with neurodevelopmental outcome at 1 year in offspring of women with gestational diabetes mellitus. Control the level of blood glucose and lipid during pregnancy and the appropriate supplementation of DHA during pregnancy in the second half of pregnancy may be beneficial to the neurodevelopment of infants.

Maternal Docosahexaenoic Acid Status during Pregnancy and Its Impact on Infant Neurodevelopment

Dietary components are essential for the structural and functional development of the brain. Among these, docosahexaenoic acid, 22:6n-3 (DHA), is critically necessary for the structure and development of the growing fetal brain in utero. DHA is the major n-3 long-chain polyunsaturated fatty acid in brain gray matter representing about 15% of all fatty acids in the human frontal cortex. DHA affects neurogenesis, neurotransmitter, synaptic plasticity and transmission, and signal transduction in the brain. Data from human and animal studies suggest that adequate levels of DHA in neural membranes are required for maturation of cortical astrocyte, neurovascular coupling, and glucose uptake and metabolism. Besides, some metabolites of DHA protect from oxidative tissue injury and stress in the brain. A low DHA level in the brain results in behavioral changes and is associated with learning difficulties and dementia. In humans, the third trimester-placental supply of maternal DHA to the growing fetus is critically important as the growing brain obligatory requires DHA during this window period. Besides, DHA is also involved in the early placentation process, essential for placental development. This underscores the importance of maternal intake of DHA for the structural and functional development of the brain. This review describes DHA’s multiple roles during gestation, lactation, and the consequences of its lower intake during pregnancy and postnatally on the 2019 brain development and function.

Association between omega-3 fatty acid supplementation and lower risk of preterm delivery: a systematic review and meta-analysis

OBJECTIVE

To explore whether omega-3 fatty acid supplementation is associated with lower risk of preterm delivery.

METHODS

Searching the RCTs which were compared preterm birth between women with omega-3 fatty acid supplementation and without before December 2019 on Medline, EMBASE and Cochrane's Library, then performing a meta-analysis.

RESULTS

26 trials were identified, included 20124 women. There was almost no association between omega-3 fatty acid supplementation and lower risk of preterm delivery (risk ratio 0.92, 95% confidence interval 0.85 to 1.01, I² = 9%), gestational duration (0.30, -0.05 to 0.64, I² = 48%). In subgroup analyses, preterm delivery lower rate occurred in groups with mixed DHA and EPA supplementation not only DHA supplementation groups (P for interaction = 0.02); The dose of equivalent greater than 1 g made a higher reduction in preterm birth significantly.

CONCLUSIONS

Omega-3 fatty acid supplementation was not associated with reduced risk of preterm delivery compared with placebo or no treatment during pregnancy. Relationship between Omega-3 fatty acid supplementation and other pregnant outcomes need more evidence and clinical studies.

Effect of supplementary omega-3 fatty acids on pregnant women with complications and pregnancy outcomes: review from literature

Numerous benefits have been associated with omega-3 fatty acid consumption during pregnancy and the postpartum period, whether it is consumed in the diet with seafood or via supplements such as fish oil. This review primarily aimed to assess the current situation of the impact of omega-3 long-chain Poly Unsaturated Fatty Acid (PUFA) supplementation on the outcomes of pregnancy. The electronic search of Medline, PubMed, Public Library of Science (PLOS) and Google Scholar databases was carried out for papers from 01 February 1995 to 01 March 2017 using keywords such as "pregnancy," "supplement," "long-chain polyunsaturated fatty acids," "omega 3 fatty acids," and "clinical trials." Out of twenty-six studies, both observational and interventional, fourteen studies found the influence of omega 3 fatty acids during pregnancy or the early postpartum period on the duration of gestation and infant size at birth, preeclampsia, depression, and infant visual function and neurodevelopment have been reported. Omega 3 fatty acid intakes (both in terms of absolute amounts of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and the ratio of these 2 fatty acids) varied widely in these studies, however, and no clear consensus exists regarding the effects of omega 3 fatty acids on any of these outcomes. Because of the potential importance of these fatty acids for pregnant or lactating women, fetus, and newborn infants and the limited data from clinical trials assessing the effect of these fatty acids on pregnancy and infant outcomes, additional research is required to better define optimal intakes of specific omega 3 fatty acids during these critical periods.

Maternal fats and pregnancy complications: Implications for long-term health

Pregnancy imposes increased nutritional requirements for the well being of the mother and fetus. Maternal lipid metabolism is critical for fetal development and long-term health of the offspring as it plays a key role in energy storage, tissue growth and cell signaling. Maternal fat composition is considered as a modifiable risk for abnormal lipid metabolism and glucose tolerance during pregnancy. Data derived from observational studies demonstrate that higher intake of saturated fats during pregnancy is associated with pregnancy complications (preeclampsia, gestational diabetes mellitus and preterm delivery) and poor birth outcomes (intra uterine growth retardation and large for gestational age babies). On the other hand, prenatal long chain polyunsaturated fatty acids status is shown to improve birth outome. In this article, we discuss the role of maternal lipids during pregnancy on fetal growth and development and its consequences on the health of the offspring.

Omega-3 fatty acid addition during pregnancy

BACKGROUND

Higher intakes of foods containing omega-3 long-chain polyunsaturated fatty acids (LCPUFA), such as fish, during pregnancy have been associated with longer gestations and improved perinatal outcomes. This is an update of a review that was first published in 2006.

OBJECTIVES

To assess the effects of omega-3 LCPUFA, as supplements or as dietary additions, during pregnancy on maternal, perinatal, and neonatal outcomes and longer-term outcomes for mother and child.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (16 August 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing omega-3 fatty acids (as supplements or as foods, stand-alone interventions, or with a co-intervention) during pregnancy with placebo or no omega-3, and studies or study arms directly comparing omega-3 LCPUFA doses or types. Trials published in abstract form were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, assessed risk of bias in trials and assessed quality of evidence for prespecified birth/infant, maternal, child/adult and health service outcomes using the GRADE approach.

MAIN RESULTS

In this update, we included 70 RCTs (involving 19,927 women at low, mixed or high risk of poor pregnancy outcomes) which compared omega-3 LCPUFA interventions (supplements and food) compared with placebo or no omega-3. Overall study-level risk of bias was mixed, with selection and performance bias mostly at low risk, but there was high risk of attrition bias in some trials. Most trials were conducted in upper-middle or high-income countries; and nearly half the trials included women at increased/high risk for factors which might increase the risk of adverse maternal and birth outcomes.Preterm birth < 37 weeks (13.4% versus 11.9%; risk ratio (RR) 0.89, 95% confidence interval (CI) 0.81 to 0.97; 26 RCTs, 10,304 participants; high-quality evidence) and early preterm birth < 34 weeks (4.6% versus 2.7%; RR 0.58, 95% CI 0.44 to 0.77; 9 RCTs, 5204 participants; high-quality evidence) were both lower in women who received omega-3 LCPUFA compared with no omega-3. Prolonged gestation > 42 weeks was probably increased from 1.6% to 2.6% in women who received omega-3 LCPUFA compared with no omega-3 (RR 1.61 95% CI 1.11 to 2.33; 5141 participants; 6 RCTs; moderate-quality evidence).For infants, there was a possibly reduced risk of perinatal death (RR 0.75, 95% CI 0.54 to 1.03; 10 RCTs, 7416 participants; moderate-quality evidence: 62/3715 versus 83/3701 infants) and possibly fewer neonatal care admissions (RR 0.92, 95% CI 0.83 to 1.03; 9 RCTs, 6920 participants; moderate-quality evidence - 483/3475 infants versus 519/3445 infants). There was a reduced risk of low birthweight (LBW) babies (15.6% versus 14%; RR 0.90, 95% CI 0.82 to 0.99; 15 trials, 8449 participants; high-quality evidence); but a possible small increase in large-for-gestational age (LGA) babies (RR 1.15, 95% CI 0.97 to 1.36; 6 RCTs, 3722 participants; moderate-quality evidence, for omega-3 LCPUFA compared with no omega-3. Little or no difference in small-for-gestational age or intrauterine growth restriction (RR 1.01, 95% CI 0.90 to 1.13; 8 RCTs, 6907 participants; moderate-quality evidence) was seen.For the maternal outcomes, there is insufficient evidence to determine the effects of omega-3 on induction post-term (average RR 0.82, 95% CI 0.22 to 2.98; 3 trials, 2900 participants; low-quality evidence), maternal serious adverse events (RR 1.04, 95% CI 0.40 to 2.72; 2 trials, 2690 participants; low-quality evidence), maternal admission to intensive care (RR 0.56, 95% CI 0.12 to 2.63; 2 trials, 2458 participants; low-quality evidence), or postnatal depression (average RR 0.99, 95% CI 0.56 to 1.77; 2 trials, 2431 participants; low-quality evidence). Mean gestational length was greater in women who received omega-3 LCPUFA (mean difference (MD) 1.67 days, 95% CI 0.95 to 2.39; 41 trials, 12,517 participants; moderate-quality evidence), and pre-eclampsia may possibly be reduced with omega-3 LCPUFA (RR 0.84, 95% CI 0.69 to 1.01; 20 trials, 8306 participants; low-quality evidence).For the child/adult outcomes, very few differences between antenatal omega-3 LCPUFA supplementation and no omega-3 were observed in cognition, IQ, vision, other neurodevelopment and growth outcomes, language and behaviour (mostly low-quality to very low-quality evidence). The effect of omega-3 LCPUFA on body mass index at 19 years (MD 0, 95% CI -0.83 to 0.83; 1 trial, 243 participants; very low-quality evidence) was uncertain. No data were reported for development of diabetes in the children of study participants.

AUTHORS' CONCLUSIONS

In the overall analysis, preterm birth < 37 weeks and early preterm birth < 34 weeks were reduced in women receiving omega-3 LCPUFA compared with no omega-3. There was a possibly reduced risk of perinatal death and of neonatal care admission, a reduced risk of LBW babies; and possibly a small increased risk of LGA babies with omega-3 LCPUFA.For our GRADE quality assessments, we assessed most of the important perinatal outcomes as high-quality (e.g. preterm birth) or moderate-quality evidence (e.g. perinatal death). For the other outcome domains (maternal, child/adult and health service outcomes) GRADE ratings ranged from moderate to very low, with over half rated as low. Reasons for downgrading across the domain were mostly due to design limitations and imprecision.Omega-3 LCPUFA supplementation during pregnancy is an effective strategy for reducing the incidence of preterm birth, although it probably increases the incidence of post-term pregnancies. More studies comparing omega-3 LCPUFA and placebo (to establish causality in relation to preterm birth) are not needed at this stage. A further 23 ongoing trials are still to report on over 5000 women, so no more RCTs are needed that compare omega-3 LCPUFA against placebo or no intervention. However, further follow-up of completed trials is needed to assess longer-term outcomes for mother and child, to improve understanding of metabolic, growth and neurodevelopment pathways in particular, and to establish if, and how, outcomes vary by different types of omega-3 LCPUFA, timing and doses; or by characteristics of women.

Dietary choline and phospholipid supplementation enhanced docosahexaenoic acid enrichment in egg yolk of laying hens fed a 2% Schizochytrium powder-added diet

The aim of this study was to evaluate the effect of dietary phospholipid supplementation on laying hen performance, egg quality, and the fatty acid profile of egg yolks from hens fed a 2% Schizochytrium powder diet. Three-hundred-sixty 28-wk-old Hy-line W-36 laying hens were randomly allocated to one of the 5 dietary treatments, each treatment with 6 replicates of 12 birds each. All diets included 2% Schizochytrium powder (docosahexaenoic acid [DHA], 137.09 mg/g). The control group was not supplemented with any additional phospholipids, whereas the other 4 experimental diets were supplemented with 1,000 mg/kg choline (CHO), 1,000 mg/kg monoethanolamine (MEA), 1,000 mg/kg lysophosphatidylcholine (LPC), or 500 mg/kg LPC + 500 mg/kg MEA (LPC + MEA). The experimental diets were isocaloric (metabolizable energy, 11.15 MJ/kg) and isonitrogenous (crude protein, 16.60%). The feeding trial lasted 28 days. Laying hen performance and egg quality were not affected (P > 0.05) by the diets used. The monounsaturated fatty acid (MUFA) level was reduced in the LPC group at d 28 (P < 0.01), whereas the polyunsaturated fatty acid (PUFA) level was increased (P < 0.05). The omega-6 (n-6) PUFA level of the egg yolks in the LPC group had a trend to increase in comparison to the control (P = 0.07). The CHO and LPC groups had higher omega-3 (n-3) PUFA and DHA levels and lower n-6/n-3 ratios than the other groups at d 28 (P < 0.01). The DHA content in egg yolk reached a plateau after the laying hens consumed the experimental diets for 14 days, and higher yolk DHA contents were observed in the CHO and LPC groups as compared with the other groups at d 14. It was concluded that dietary choline supplementation for more than 14 d enhanced egg yolk enrichment with n-3 PUFA and DHA when laying hen diets were supplemented with 2% Schizochytrium powder. All the diets had no adverse effect on hen performance, egg quality, or egg components under the experimental condition.

Docosahexaenoic acid (DHA), a fundamental fatty acid for the brain: New dietary sources

Docosahexaenoic acid (C22: 6n-3, DHA) is a long-chain polyunsaturated fatty acid of marine origin fundamental for the formation and function of the nervous system, particularly the brain and the retina of humans. It has been proposed a remarkable role of DHA during human evolution, mainly on the growth and development of the brain. Currently, DHA is considered a critical nutrient during pregnancy and breastfeeding due their active participation in the development of the nervous system in early life. DHA and specifically one of its derivatives known as neuroprotectin D-1 (NPD-1), has neuroprotective properties against brain aging, neurodegenerative diseases and injury caused after brain ischemia-reperfusion episodes. This paper discusses the importance of DHA in the human brain given its relevance in the development of the tissue and as neuroprotective agent. It is also included a critical view about the ways to supply this noble fatty acid to the population.

Effects of maternal omega-3 fatty acids supplementation during pregnancy/lactation on body composition of the offspring: A systematic review and meta-analysis

BACKGROUND & AIMS

The effect of maternal omega-3 fatty acids intake on the body composition of the offspring is unclear. The aim of this study was to conduct a systematic review and meta-analysis to confirm the effects of omega-3 fatty acids supplementation during pregnancy and/or lactation on body weight, body length, body mass index (BMI), waist circumference, fat mass and sum of skinfold thicknesses of offspring.

METHODS

Human intervention studies were selected by a systematic search of PubMed, Web of Science, the Cochrane Library and references of related reviews and studies. Randomized controlled trials of maternal omega-3 fatty acids intake during pregnancy or lactation for offspring's growth were included. The data were analyzed with RevMan 5.3 and Stata 12.0. Effect sizes were presented as weighted mean differences (WMD) or standardized mean difference (SMD) with 95% confidence intervals (95% CI).

RESULTS

Twenty-six studies comprising 10,970 participants were included. Significant increases were found in birth weight (WMD = 42.55 g, 95% CI: 21.25, 63.85) and waist circumference (WMD = 0.35 cm, 95% CI: 0.04, 0.67) in the omega-3 fatty acids group. There were no effects on birth length (WMD = 0.09 cm, 95% CI: -0.03, 0.21), postnatal length (WMD = 0.13 cm, 95% CI: -0.11, 0.36), postnatal weight (WMD = 0.04 kg, 95% CI: -0.07, 0.14), BMI (WMD = 0.09, 95% CI: -0.05, 0.23), the sum of skinfold thicknesses (WMD = 0.45 mm, 95% CI: -0.30, 1.20), fat mass (WMD = 0.05 kg, 95% CI: -0.01, 0.11) and the percentage of body fat (WMD = 0.04%, 95% CI: -0.38, 0.46).

CONCLUSIONS

This meta-analysis showed that maternal omega-3 fatty acids supplementation can increase offspring's birth weight and postnatal waist circumference. However, it did not appear to influence children's birth length, postnatal weight/length, BMI, sum of skinfold thicknesses, fat mass and the percentage of body fat during postnatal period. Larger, well-designed studies are recommended to confirm this conclusion.

Assessment of DHA on reducing early preterm birth: the ADORE randomized controlled trial protocol

BACKGROUND

Preterm birth contributes to 0.5 million deliveries in the United States (one of eight pregnancies) and poses a huge burden on public health with costs in the billions. Of particular concern is that the rate of earliest preterm birth (<34 weeks) (ePTB), which has decreased little since 1990 and has the greatest impact on the overall infant mortality, resulting in the greatest cost to society. Docosahexaenoic acid (DHA) supplementation provides a potential high yield, low risk strategy to reduce early preterm delivery in the US by up to 75%. We propose a Phase III Clinical Trial (randomized to low or high dose DHA, double-blinded) to examine the efficacy and safety of high dose DHA supplementation to reduce ePTB. We also plan for a secondary pregnancy efficacy analysis to determine if there is a subset of pregnancies most likely to benefit from DHA supplementation.

METHODS

Between 900 and 1200 pregnant women who are ≥ 18 years old and between 12 and 20 weeks gestation will be recruited from three trial experienced academic medical institutions. Participants will be randomly assigned to two daily capsules of algal oil (totaling 800 mg DHA) or soybean and corn oil (0 mg DHA). Both groups will receive a commercially available prenatal supplement containing 200 mg DHA. Therefore, the experimental group will receive 1000 mg DHA/d and the control group 200 mg DHA/d. We will then employ a novel Bayesian response adaptive randomization design that assigns more subjects to the "winning" group and potentially allows for substantially smaller sample size while providing a stronger conclusion regarding the most effective group. The study has an overall Type I error rate of 5% and a power of 90%. Participants are followed throughout pregnancy and delivery for safety and delivery outcomes.

DISCUSSION

We hypothesize that DHA will decrease the frequency of ePTB <34 weeks. Reducing ePTB is clinically important as these earliest preterm deliveries carry the highest risk of neonatal morbidity, as well as contribute significant stress for families and post a large societal burden.

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov (identifier: NCT02626299 ) on December 8, 2015. Additional summary details may be found in Table 1.

Reduced DHA transfer in diabetic pregnancies: mechanistic basis and long-term neurodevelopmental implications

Infants born to diabetic mothers have a higher frequency of impaired neurodevelopment. The omega-3 or n-3 fatty acid docosahexaenoic acid (DHA) is an important structural component of neural tissue and is critical for fetal brain development. Maternal DHA supplementation during pregnancy is linked to better infant neurodevelopment; however, maternal-fetal transfer of DHA is reduced in women with diabetes. Evidence of mechanisms explaining altered maternal-fetal DHA transfer in this population is limited. This review explores existing evidence underpinning reduced maternal-fetal DHA transfer in maternal fuel metabolism in this population. Further research is necessary to evaluate the role of peroxisome proliferator-activated receptors in modulating placental fatty acid binding and maternal-fetal DHA transfer. Considerations for clinical practice include a diet high in DHA and/or provision of supplemental DHA to obstetric diabetic patients within minimum guidelines.

Maternal Fatty Acids and Their Association with Birth Outcome: A Prospective Study

Maternal nutrition, especially LCPUFA, is an important factor in determining fetal growth and development. Our earlier cross sectional study reports lower docosahexanoic acid (DHA) levels at the time of delivery in mothers delivering low birth weight (LBW) babies. This study was undertaken to examine the role of the maternal omega-3 and omega-6 fatty acid profile across the gestation in fetal growth. This is a hospital based study where women were recruited in early gestation. Maternal blood was collected at 3 time points, i.e., T1 = 16^th–20^th week, T2 = 26^th–30^th week and T3 = at delivery. Cord blood was collected at delivery. At delivery, these women were divided into 2 groups: those delivering at term a baby weighing >2.5kg [Normal birth weight (NBW) group] and those delivering at term a baby weighing <2.5kg [LBW group]. The study reports data on 111 women recruited at T1, out of which 60 women delivered an NBW baby at term and 51 women delivered an LBW baby at term. Fatty acids were analysed using gas chromatography. At T1 of gestation, maternal erythrocyte DHA levels were positively (p<0.05) associated with baby weight. Maternal plasma and erythrocyte arachidonic acid and total erythrocyte omega-6 fatty acid levels at T2 were higher (p<0.05 for both) in the LBW group. Total erythrocyte omega-3 fatty acid levels were lower (p<0.05) while total erythrocyte omega-6 fatty acid levels were higher (p<0.05) in the LBW group at delivery. Our data demonstrates the possible role of LCPUFA in the etiology of LBW babies right from early pregnancy.

Omega-3 supplementation during pregnancy to prevent recurrent intrauterine growth restriction: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the efficacy of omega-3 supplementation during pregnancy in preventing intrauterine growth restriction (IUGR) in women with apparently uncomplicated singleton pregnancy and previous IUGR pregnancy.

METHODS

For this systematic review, the research protocol was designed a priori. Searches were performed in electronic databases for studies published from inception of each database to December 2014. A combination of search terms was used including 'fish oil', 'long chain polyunsaturated fatty acids', 'intrauterine growth restriction', 'small for gestational age' and 'omega-3'. We included all randomized controlled trials (RCTs) of women with an uncomplicated singleton pregnancy and a prior IUGR pregnancy who were randomized to receive prophylactic treatment with omega-3 supplementation or either placebo or no treatment (control). Trials that included women with multiple gestations and those with only biochemical outcomes available were excluded. Pooled estimates were based on relative risk (RR) with 95% CI. Primary outcome was incidence of IUGR as defined in the RCTs.

RESULTS

Three RCTs including 575 women with uncomplicated singleton pregnancy with prior IUGR were analyzed. Women who received omega-3 supplementation during pregnancy had the same incidence of IUGR, defined as estimated fetal weight < 5(th) or < 3(rd) centiles, as had controls (22.8% vs 20.2%, respectively; RR, 1.13 (95% CI, 0.83-1.54)). Compared to controls, women who received omega-3 supplementation delivered later (mean difference, 1.4 (95% CI, 1.28-1.63) weeks), had a longer latency (mean difference, 2 (95% CI, 1.73-2.08) weeks), had a similar incidence of perinatal death (2.1% vs 3.3%, respectively; RR, 0.60 (95% CI, 0.15-2.42)) and similar birth weight (mean difference, 50 g (95% CI, -26 to 246 g)).

CONCLUSIONS

Omega-3 supplementation during pregnancy does not prevent recurrence of IUGR in women with uncomplicated singleton pregnancy and a previous IUGR pregnancy.

Omega-3 long-chain polyunsaturated fatty acids and fish oil supplementation during pregnancy: which evidence?

OBJECTIVE

The aim of this study was to provide evidence-based recommendations for omega-3 supplementation during pregnancy through a systematic review of level-1 data published on this topic.

METHODS

We reviewed all randomized-controlled trials (RCTs) including women who were randomized to treatment with either omega-3 supplementation or control (placebo or no treatment) during pregnancy and analyzed all the outcomes reported in the trials, separately. We planned to evaluate the effect of omega-3 on: preterm birth (PTB); pre-eclampsia (PE) and intrauterine growth restriction (IUGR); gestational diabetes; perinatal mortality; small for gestational age (SGA) and birth weight; infant eye and brain development; and postpartum depression.

RESULTS

We identified 34 RCTs including 14 106 singletons and 2578 twins. These level-1 data showed that omega-3 was not associated with prevention of PTB, PE, IUGR, gestational diabetes, SGA, post-partum depression or better children development. Data about birth weight, perinatal mortality and childhood cognitive outcome were limited. Women with gestational diabetes who received omega-3 had significantly lower serum C-reactive protein concentrations, low incidence of hyperbilirubinemia in newborns and decreased newborns' hospitalization rate.

CONCLUSIONS

There was not enough evidence to support the routine use of omega-3 supplementation during pregnancy. Given the 73% significant decrease in perinatal death in the singleton gestations who started omega-3 supplementation ≤ 20 weeks, further research is needed. Large RCTs in multiple gestations and longer follow-up are also required.

Fish Oil Supplementation does not Reduce Risks of Gestational Diabetes Mellitus, Pregnancy-Induced Hypertension, or Pre-Eclampsia: A Meta-Analysis of Randomized Controlled Trials

Background

The effects of gestational supplementation with fish oil on risks for gestational diabetes mellitus (GDM), pregnancy-induced hypertension (PIH), and pre-eclampsia (PE) have not been confirmed. In this study, a meta-analysis was performed to evaluate the effect of fish oil supplementation on these gestational complications.

Material/Methods

Randomized controlled human trials that investigated the effects of fish oil supplementation in pregnant women were identified by a systematic search of Medline, Embase, and Cochrane’s Library, and references of related reviews and studies up to December 2014. Relative risks (RRs) for GDM, PIH, and PE were the outcomes of interest. Fixed-effects or random-effects models were applied according to the heterogeneity.

Results

Thirteen comparisons from 11 published articles, including more than 5000 participants, were included. The results showed that fish oil supplementation was not associated with reduced risks for GDM (RR=1.06, 95% confidence interval [CI]: 0.85–1.32, p=0.60), PIH (RR=1.03, 95% CI: 0.89–1.20, p=0.66), or PE (RR=0.93, 95% CI: 0.74–1.16, p=0.51). No statistically significant heterogeneity was detected for the comparison of each outcome. The effects of fish oil on these gestational complications were consistent between women with low-risk and high-risk pregnancies.

Conclusions

Gestational supplementation with fish oil during the second or third trimester of pregnancy is not associated with reduced risks for GDM, PIH, or PE. Other possible benefits of fish oil supplementation during pregnancy warrant further evaluation.

Omega-3 supplementation to prevent recurrent preterm birth: a systematic review and metaanalysis of randomized controlled trials

The purpose of this study was to evaluate the efficacy of omega-3 supplementation for the prevention of recurrent preterm birth (PTB) in asymptomatic singleton gestations with previous PTB. We searched fish oil, long chain polyunsaturated fatty acids, pregnancy, and omega-3 in MEDLINE, OVID, Scopus, ClinicalTrials.gov, the PROSPERO International Prospective Register of Systematic Reviews, EMBASE, and the Cochrane Central Register of Controlled Trials from inception of each database to December 2014 with no limit for language. In addition the reference lists of all identified articles were examined to identify studies that were not captured by electronic searches. We performed a metaanalysis of randomized controlled trials of asymptomatic singleton gestations with previous PTB who were assigned randomly to prophylactic omega-3 supplementation vs control (either placebo or no treatment). The primary outcome was predefined as PTB at <37 weeks of gestation. The pooled results were reported as relative risk (RR) with 95% confidence interval (95% CI). The protocol of this review was registered with PROSPERO (registration number: CRD42015016371). Two randomized controlled trials that included 1080 women were analyzed. The mean gestational age at randomization was approximately 134 days in both groups (mean difference, 0.01 days; 95% CI, -0.13 to 0.14). Women who received omega-3 had similar rates of PTB at <37 weeks of gestation (34.5% vs 39.8%; RR, 0.81; 95% CI, 0.59-1.12) and PTB at <34 weeks of gestation (12.0% vs 15.4%; RR, 0.62; 95% CI, 0.26-1.46) compared with control subjects. The omega-3 groups had a statistically significantly longer latency (mean difference, 2.10 days; 95% CI, 1.98-2.22) and higher birthweight (mean difference, 102.52 g; 95% CI, 20.09-184.95) compared with control subjects; the other secondary outcomes (which included gestational age at delivery, spontaneous PTB at <37 and 34 weeks of gestation, admission to the intensive care unit, intraventricular hemorrhage, necrotizing enterocolitis, sepsis, and perinatal death) were similar. Omega-3 supplementation during pregnancy does not prevent recurrent PTB in asymptomatic singleton gestations with previous PTB. The benefits in longer latency and higher birth weight may deserve further study.

Omega-3 long chain polyunsaturated fatty acids to prevent preterm birth: a systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of omega-3 in reducing the incidence of preterm birth.

DATA SOURCES

Searches were performed in MEDLINE, OVID, Scopus, ClinicalTrials.gov, the PROSPERO International Prospective Register of Systematic Reviews, EMBASE, and the Cochrane Central Register of Controlled Trials with the use of a combination of keywords related to "fish oil," "pregnancy," and "omega-3."

METHODS OF STUDY SELECTION

We included all randomized controlled trials of asymptomatic women with singleton gestations who were randomized to prophylactic treatment with either omega-3 supplementation or control (either placebo or no treatment). Exclusion criteria included trials in women with multiple gestations, intrauterine growth restriction, gestational hypertension or preeclampsia at randomization, prior preterm birth, and trials with polyunsaturated fatty acids as control.

TABULATION, INTEGRATION, AND RESULTS

Nine randomized trials including 3,854 eligible women were identified. Women who received omega-3 had a similar rate of preterm birth before 37 weeks of gestation compared with women in the control group (7.7% compared with 9.1%, respectively; relative risk 0.90, 95% confidence interval [CI] 0.72-1.11). There were no significant differences in birth weight, neonatal intensive care unit admission, necrotizing enterocolitis, sepsis, or perinatal death in the omega-3 compared with control groups, respectively. There were no significant differences in the subgroup analyses, except for the rate of perinatal death, which was lower (0.3% compared with 1.2%; relative risk 0.27, 95% CI 0.09-0.80) in the women who received omega-3 before 21 weeks of gestation and in trials with low risk of bias (0.3% compared with 1.0%; relative risk 0.28, 95% CI 0.09-0.89) compared with women in the control group. However, in no randomized controlled trial was perinatal death the primary outcome.

CONCLUSION

Omega-3 supplementation during pregnancy does not reduce the incidence of preterm birth or improve neonatal outcome.

Outcomes for patients with the same disease treated inside and outside of randomized trials: a systematic review and meta-analysis

BACKGROUND

It is unclear whether participation in a randomized controlled trial (RCT), irrespective of assigned treatment, is harmful or beneficial to participants. We compared outcomes for patients with the same diagnoses who did ("insiders") and did not ("outsiders") enter RCTs, without regard to the specific therapies received for their respective diagnoses.

METHODS

By searching the MEDLINE (1966-2010), Embase (1980-2010), CENTRAL (1960-2010) and PsycINFO (1880-2010) databases, we identified 147 studies that reported the health outcomes of "insiders" and a group of parallel or consecutive "outsiders" within the same time period. We prepared a narrative review and, as appropriate, meta-analyses of patients' outcomes.

RESULTS

We found no clinically or statistically significant differences in outcomes between "insiders" and "outsiders" in the 23 studies in which the experimental intervention was ineffective (standard mean difference in continuous outcomes -0.03, 95% confidence interval [CI] -0.1 to 0.04) or in the 7 studies in which the experimental intervention was effective and was received by both "insiders" and "outsiders" (mean difference 0.04, 95% CI -0.04 to 0.13). However, in 9 studies in which an effective intervention was received only by "insiders," the "outsiders" experienced significantly worse health outcomes (mean difference -0.36, 95% CI -0.61 to -0.12).

INTERPRETATION

We found no evidence to support clinically important overall harm or benefit arising from participation in RCTs. This conclusion refutes earlier claims that trial participants are at increased risk of harm.

Effects of dietary interventions on neonatal and infant outcomes: a systematic review and meta-analysis

BACKGROUND

Nutrition plays a fundamental role in fetal growth and birth outcomes.

OBJECTIVE

We synthesized effects of dietary interventions before or during pregnancy on neonatal and infant outcomes.

DESIGN

Randomized controlled trials that assessed the whole diet or dietary components and neonatal or infant outcomes were included. Two authors independently identified articles to be included and assessed the methodologic quality. A meta-analysis was conducted separately for each outcome by using a random-effects model. Results were reported by dietary intervention as follows: 1) counseling, 2) food and fortified food products, or 3) a combination (counseling plus food) intervention, and 4) collectively for all dietary interventions. Results were subanalyzed by the nutrient of interest, country income, and BMI.

RESULTS

Of 2326 abstracts screened, a total of 29 randomized controlled trials (31 publications) were included in this review. Food and fortified food products were effective in increasing birth weight [standardized mean difference (SMD): 0.27; 95% CI: 0.14, 0.40; P < 0.01] and reducing the incidence of low birth weight (SMD: -0.22; 95% CI: -0.37, -0.06; P < 0.01). All dietary interventions and those focused on macronutrient intake also increased birth weight (P < 0.01) and length (P < 0.05) and reduced the incidence of low birth weight (P < 0.01). Dietary interventions in low-income countries and underweight or nutritionally at-risk populations increased birth weight (P < 0.05) and reduced the incidence of low birth weight (P = 0.01). No effects were seen for the following other outcomes: placental weight, head circumference, macrosomia, Apgar score, small for gestational age, large for gestational age, and perinatal mortality.

CONCLUSION

Additional high-quality randomized controlled trials that test different dietary interventions are required to identify maternal diet intakes that optimize neonatal and infant outcomes.

Effects of dietary interventions on pregnancy outcomes: a systematic review and meta-analysis

Dietary intake during pregnancy influences maternal health. Poor dietary practices during pregnancy have been linked to maternal complications. The objective was to determine the effect of dietary intervention before or during pregnancy on pregnancy outcomes. A systematic review was conducted without date restrictions. Randomised controlled trials (RCTs) evaluating whole diet or dietary components and pregnancy outcomes were included. Two authors independently identified papers for inclusion and assessed methodological quality. Meta-analysis was conducted separately for each outcome using random effects models. Results were reported by type of dietary intervention: (1) counselling; (2) food and fortified food products; or (3) combination (counseling + food); and collectively for all dietary interventions. Results were further grouped by trimester when the intervention commenced, nutrient of interest, country income and body mass index. Of 2326 screened abstracts, a total of 28 RCTs were included in this review. Dietary counselling during pregnancy was effective in reducing systolic [standardised mean difference (SMD) -0.26, 95% confidence interval (CI) -0.45 to -0.07; P < 0.001] and diastolic blood pressure (SMD -0.57, 95% CI -0.75 to -0.38; P < 0.001). Macronutrient dietary interventions were effective in reducing the incidence of preterm delivery (SMD -0.19, 95% CI -0.34 to -0.04; P = 0.01). No effects were seen for other outcomes. Dietary interventions showed some small, but significant differences in pregnancy outcomes including a reduction in the incidence of preterm birth. Further high-quality RCTs, investigating micronutrient provision from food, and combination dietary intervention, are required to identify maternal diet intakes that optimise pregnancy outcomes.

Different intakes of n-3 fatty acids among pregnant women in 3 regions of China with contrasting dietary patterns are reflected in maternal but not in umbilical erythrocyte phosphatidylcholine fatty acid composition

There is limited information regarding the intake and status of polyunsaturated fatty acids (PUFA) in Chinese pregnant women with different dietary patterns. We hypothesize that there will be significant differences in long chain n-3 and n-6 PUFA status in pregnant women from 3 regions of China (river/lake, coastal and inland). Dietary fatty acid intakes and fatty acid profiles in maternal and umbilical erythrocyte phosphatidylcholine (PC) were analyzed. The median daily intakes (mg) of eicosapentanoic acid and docosahexaenoic acid (DHA) in the coastal group (64.6 and 93.9, n = 42) were significantly higher than those in the river/lake group (27.9 and 41.8, n = 41) and the inland group (12.1 and 41.1, n = 40). Daily intake of arachidonic acid (AA) was highest (170.2 mg) in the inland group. The median DHA level (%) of maternal erythrocyte PC was comparable between river/lake and inland groups (5.7 vs. 5.6) while both were significantly lower than in coastal group (8.4). The median AA level (%) of maternal erythrocyte PC tended to be lower in the coastal group than in the inland group but the difference was not significant. The AA and DHA levels in umbilical erythrocyte PC were comparable among the 3 groups. In conclusion, differences in long chain n-3 PUFA intake between geographic regions, in particular in DHA, were reflected in differences in maternal erythrocyte PC DHA status but did not result in differences in umbilical erythrocyte PC.

Effects of fish oil supplementation on the fatty acid profile in erythrocyte membrane and plasma phospholipids of pregnant women and their offspring: a randomised controlled trial

We aimed to investigate the effects of fish oil (FO) supplementation to pregnant women on the maternal and fetal fatty acid profile in plasma and erythrocyte phospholipids (PL) and to identify the best compartment for the assessment of fatty acid status. A multi-centre, double-blind, controlled trial was conducted. Healthy pregnant women from three European centres were randomly assigned to receive from week 20 of gestation until delivery a daily dietary supplement with either FO (500 mg DHA+150 mg EPA), 400 μg 5-methyltetrahydrofolate, both or placebo. Fatty acids in plasma and erythrocyte PL were determined in maternal blood (week 20, week 30 of pregnancy and delivery) and in cord blood (delivery). FO supplementation increased DHA levels in maternal and cord plasma and erythrocyte PL. Higher percentage changes were observed in erythrocyte PL than in plasma PL. There were significant correlations between plasma and erythrocyte fatty acid levels in maternal and cord blood. Significant correlations between maternal and cord fatty acid levels at delivery in plasma and erythrocytes were also observed; however, correlation coefficients were higher for erythrocyte phophatidylethanolamine. FO supplementation increases maternal and fetal DHA status. Both plasma and erythrocytes appear to be suitable to evaluate the fatty acid status of mothers but erythrocytes seem to be a more reliable marker in neonates.

Maternal consumption of a DHA-containing functional food benefits infant sleep patterning: an early neurodevelopmental measure

BACKGROUND

Docosahexaenoic acid (DHA; 22:6n-3) is highly important during pregnancy for optimal development and functioning of fetal neural tissue. Infant ability to organize sleep and wake states following parturition is highly associated with later developmental outcomes. The impact of maternal DHA intake on sleep organization has not been previously investigated.

AIMS

To examine the effect of a DHA-containing functional food consumed during pregnancy on early neurobehavioral development as assessed by infant sleep patterning in the first 48 postnatal hours.

STUDY DESIGN

A longitudinal, randomized, double-blinded, placebo-controlled design was used.

SUBJECTS

Women (18-35 y) with no pregnancy complications consumed a cereal-based functional food (92 kcal) containing 300 mg DHA an average of 5 d/week or placebo bars (n=27 DHA, n=21 Placebo). The intervention began at 24 weeks gestation and continued until delivery (38-40 weeks).

OUTCOME MEASURES

Infant sleep/wake states were measured on postnatal days 1 (D1) and 2 (D2) using a pressure sensitive mattress recording respiration and body movements.

RESULTS

Using ANCOVA and controlling for ethnic variation, there were significant group differences in arousals in quiet sleep on D1 (P=0.006) and D2 (P=0.011) with fewer arousals in the DHA intervention group compared to the placebo group. Similarly, arousals in active sleep on D1 were significantly lower in the DHA-intervention group (P=0.012) compared to the placebo group.

CONCLUSIONS

We conclude that increased prenatal supply of dietary DHA has a beneficial impact on infant sleep organization.

Effect of n-3 long-chain polyunsaturated fatty acid intake during pregnancy on maternal, infant, and child health outcomes: a systematic review

Evidence from observational studies and randomised trials has suggested a potential association between intake of n-3 long-chain polyunsaturated fatty acids (LCPUFA) during pregnancy and certain pregnancy and birth outcomes. Marine foods (e.g. fatty sea fish, algae) and select freshwater fish contain pre-formed n-3 LCPUFA, which serve as precursors for bioactive molecules (e.g. prostaglandins) that influence a variety of biological processes. The main objective of this analysis was to summarise evidence of the effect of n-3 LCPUFA intake during pregnancy on select maternal and child health outcomes. Searches were performed in PubMed, EMBASE, and other electronic databases to identify trials where n-3 LCPUFA were provided to pregnant women for at least one trimester of pregnancy. Data were extracted into a standardised abstraction table and pooled analyses were conducted using RevMan software. Fifteen randomised controlled trials were eligible for inclusion in the meta-analysis, and 14 observational studies were included in the general review. n-3 LCPUFA supplementation during pregnancy resulted in a modest increase in birthweight (mean difference = 42.2 g; [95% CI 14.8, 69.7]) and no significant differences in birth length or head circumference. Women receiving n-3 LCPUFA had a 26% lower risk of early preterm delivery (<34 weeks) (RR = 0.74; [95% CI 0.58, 0.94]) and there was a suggestion of decreased risk of preterm delivery (RR = 0.91; [95% CI 0.82, 1.01]) and low birthweight (RR = 0.92; [95% CI 0.83, 1.02]). n-3 LCPUFA in pregnancy did not influence the occurrence of pre-eclampsia, high blood pressure, infant death, or stillbirth. Our review of observational studies revealed mixed findings, with several large studies reporting positive associations between fish intake and birthweight and several reporting no associations. In conclusion, n-3 LCPUFA supplementation during pregnancy resulted in a decreased risk of early preterm delivery and a modest increase in birthweight. More studies in low- and middle-income countries are needed to determine any effect of n-3 LCPUFA supplementation in resource-poor settings, where n-3 PUFA intake is likely low.

Omega 3 fatty acids on child growth, visual acuity and neurodevelopment

The aim of this review is to evaluate the effects of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation in pregnant and lactating women and infants during postnatal life, on the visual acuity, psychomotor development, mental performance and growth of infants and children. Eighteen publications (11 sets of randomized control clinical trial [RCTs]) assessed the effects of the n-3 LCPUFA supplementation duringpregnancyon neurodevelopment and growth, in the same subjects at different time points; 4 publications (2 data sets from RCTs) addressed physiological responses to n-3 LCPUFA supplementation duringpregnancy & lactationand 5 publications (3 data sets from RCTs) exclusively duringlactation. Some of these studies showed beneficial effects of docosahexaenoic acid (DHA) supplementation during pregnancy and/or lactation especially on visual acuity outcomes and some on long-term neurodevelopment; a few, showed positive effects on growth. There were also 15 RCTs involving term infants who received infant formula supplemented with DHA, which met our selection criteria. Many of these studies claimed a beneficial effect of such supplementation on visual, neural, or developmental outcomes and no effects on growth. Although new well designed and conducted studies are being published, evidence from RCTs does not demonstrate still a clear and consistent benefit of n-3 LCPUFA supplementation during pregnancy and/or lactation on term infants growth, neurodevelopment and visual acuity. These results should be interpreted with caution due to methodological limitations of the included studies.

Dietary methods and biomarkers of omega 3 fatty acids: a systematic review

The aims of the present study were to review the validity of dietary methods used to measure the usual long chain (LC) omega-3 polyunsaturated fatty acid (n-3 PUFA) intake of a population and to assess the usefulness of different biomarkers of n-3 PUFA in healthy humans. Two systematic literature searches were conducted until May 2011 to update previous systematic reviews. The first literature search aimed to find studies validating the methodology used for measuring the dietary intake of n-3 PUFA. The second search aimed to find human intervention studies in which n-3 PUFA status changed after 2 weeks of n-3 PUFA supplementation. Sixteen studies were identified for inclusion in the first review. Correlation coefficients between fatty acids in subcutaneous fat or blood lipids and dietary intake of n-3 PUFA from different questionnaires were similar. Subcutaneous fat has been reported as the best reference method for some authors, and these studies showed moderate correlation coefficients with no dietary intake method being superior to any other. As for the evaluation of biomarkers of docosahexaenoic acid (DHA, 22 : 6 n-3) and eicosapentaenoic acid (EPA, 20 : 5n-3) status in response to supplementation, the new search reaffirmed and reinforced the evidence supporting that plasma phospholipid DHA, erythrocyte DHA, and platelet DHA were all effective and robust biomarkers of DHA status. Our findings only confirmed earlier studies and did not provide evidence for reaching new conclusions.

Effect of n-3 long chain polyunsaturated fatty acid supplementation in pregnancy on infants' allergies in first year of life: randomised controlled trial

OBJECTIVE

To determine whether dietary n-3 long chain polyunsaturated fatty acid (LCPUFA) supplementation of pregnant women with a fetus at high risk of allergic disease reduces immunoglobulin E associated eczema or food allergy at 1 year of age.

DESIGN

Follow-up of infants at high hereditary risk of allergic disease in the Docosahexaenoic Acid to Optimise Mother Infant Outcome (DOMInO) randomised controlled trial.

SETTING

Adelaide, South Australia.

PARTICIPANTS

706 infants at high hereditary risk of developing allergic disease whose mothers were participating in the DOMInO trial.

INTERVENTIONS

The intervention group (n=368) was randomly allocated to receive fish oil capsules (providing 900 mg of n-3 LCPUFA daily) from 21 weeks' gestation until birth; the control group (n=338) received matched vegetable oil capsules without n-3 LCPUFA.

MAIN OUTCOME MEASURE

Immunoglobulin E associated allergic disease (eczema or food allergy with sensitisation) at 1 year of age.

RESULTS

No differences were seen in the overall percentage of infants with immunoglobulin E associated allergic disease between the n-3 LCPUFA and control groups (32/368 (9%) v 43/338 (13%); unadjusted relative risk 0.68, 95% confidence interval 0.43 to 1.05, P=0.08; adjusted relative risk 0.70, 0.45 to 1.09, P=0.12), although the percentage of infants diagnosed as having atopic eczema (that is, eczema with associated sensitisation) was lower in the n-3 LCPUFA group (26/368 (7%) v 39/338 (12%); unadjusted relative risk 0.61, 0.38 to 0.98, P=0.04; adjusted relative risk 0.64, 0.40 to 1.02, P=0.06). Fewer infants were sensitised to egg in the n-3 LCPUFA group (34/368 (9%) v 52/338 (15%); unadjusted relative risk 0.61, 0.40 to 0.91, P=0.02; adjusted relative risk 0.62, 0.41 to 0.93, P=0.02), but no difference between groups in immunoglobulin E associated food allergy was seen.

CONCLUSION

n-3 LCPUFA supplementation in pregnancy did not reduce the overall incidence of immunoglobulin E associated allergies in the first year of life, although atopic eczema and egg sensitisation were lower. Longer term follow-up is needed to determine if supplementation has an effect on respiratory allergic diseases and aeroallergen sensitisation in childhood.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12610000735055 (DOMInO trial: ACTRN12605000569606).

Position of the American Dietetic Association: vegetarian diets

It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes. A vegetarian diet is defined as one that does not include meat (including fowl) or seafood, or products containing those foods. This article reviews the current data related to key nutrients for vegetarians including protein, n-3 fatty acids, iron, zinc, iodine, calcium, and vitamins D and B-12. A vegetarian diet can meet current recommendations for all of these nutrients. In some cases, supplements or fortified foods can provide useful amounts of important nutrients. An evidence- based review showed that vegetarian diets can be nutritionally adequate in pregnancy and result in positive maternal and infant health outcomes. The results of an evidence-based review showed that a vegetarian diet is associated with a lower risk of death from ischemic heart disease. Vegetarians also appear to have lower low-density lipoprotein cholesterol levels, lower blood pressure, and lower rates of hypertension and type 2 diabetes than nonvegetarians. Furthermore, vegetarians tend to have a lower body mass index and lower overall cancer rates. Features of a vegetarian diet that may reduce risk of chronic disease include lower intakes of saturated fat and cholesterol and higher intakes of fruits, vegetables, whole grains, nuts, soy products, fiber, and phytochemicals. The variability of dietary practices among vegetarians makes individual assessment of dietary adequacy essential. In addition to assessing dietary adequacy, food and nutrition professionals can also play key roles in educating vegetarians about sources of specific nutrients, food purchase and preparation, and dietary modifications to meet their needs.

Long chain fatty acids and dietary fats in fetal nutrition

Long chain polyunsaturated fatty acids are essential nutrients for a healthy diet. The different kinds consumed by the mother during gestation and lactation may influence pregnancy, fetal and also neonatal outcome. The amount of fatty acids transferred from mother to fetus depends not only on maternal metabolism but also on placental function, i.e. by the uptake, metabolism and then transfer of fatty acids to the fetus. The third trimester of gestation is characterized by an increase of long chain polyunsaturated fatty acids in the fetal circulation, in particular docosahexaenoic acid, especially to support brain growth and visual development. These mechanisms may be altered in pathological conditions, such as intrauterine growth restriction and diabetes, when maternal and fetal plasma levels of long chain polyunsaturated fatty acids undergo significant changes. The aim of this review is to describe the maternal and placental factors involved in determining fetal fatty acid availability and metabolism, focusing on the specific role of long chain polyunsaturated fatty acids in normal and pathological pregnancies.

Plasma or red blood cell phospholipids can be used to assess docosahexaenoic acid status in women during pregnancy

The suitability of using plasma phopholipids (PLs) to assess docosahexaenoic acid (DHA) status during pregnancy is well accepted. Recent discussions have centered around whether red blood cells (RBCs) can be used to indicate DHA status. We tested the hypothesis that in pregnant women participating in an intervention study when fed a functional food containing DHA, maternal plasma PL DHA would be positively associated with maternal RBC PL and umbilical cord blood RBC PL DHA. Maternal and umbilical cord blood samples were obtained at delivery from women whose mean dietary intake was 187 mg/d (including the amount consumed from the DHA-functional food). Maternal plasma and RBCs and cord blood RBC lipids were extracted and PLs separated by thin-layer chromatography. Phopholipid lipids were methylated, and fatty acids were identified using gas chromatography. Fifty-nine maternal samples and 30 cord blood samples were analyzed. There were moderate to strong correlations between DHA in all compartments (maternal plasma vs maternal RBC PL DHA weight percent [wt%], r = 0.633, P < or = .001; maternal plasma vs cord blood RBC PL DHA wt%, r = 0.458, P < or = .01; maternal RBCs vs cord blood RBC PL DHA wt%, r = 0.376, P < or = .01). These results support the practice of using either plasma PLs or RBC PLs to assess maternal and infant DHA status.

Methods of assessment of n-3 long-chain polyunsaturated fatty acid status in humans: a systematic review

BACKGROUND

The availability of reliable biomarkers of n-3 (omega-3) long-chain polyunsaturated fatty acid (LCPUFA) status is a prerequisite for linking dietary n-3 LCPUFA status to clinical outcomes.

OBJECTIVE

The objective of this meta-analysis was to assess the usefulness of different biomarkers of n-3 LCPUFA status in healthy humans.

DESIGN

We searched Ovid MEDLINE, EMBASE (Ovid), and Cochrane databases from inception to September 2007 for human intervention studies in which n-3 LCPUFA status changed after > or =2 wk of n-3 LCPUFA supplementation. We used formal inclusion/exclusion criteria and applied standard procedures for data extraction, validity assessment, and meta-analysis.

RESULTS

We included 41 studies (34 randomized controlled trials and 7 before-after studies) reporting on 18 different biomarkers. The data allowed specific evaluation of biomarkers of docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3) status in response to supplementation. There were sufficient data to determine that plasma DHA, plasma phospholipid DHA, plasma triacylglycerol DHA, plasma cholesteryl ester DHA, plasma nonesterified DHA, erythrocyte DHA, erythrocyte phospholipid DHA, and platelet DHA were all effective biomarkers of DHA status and that plasma phospholipid EPA was an effective marker of EPA status. Plasma phospholipid DHA appears to be a good marker of DHA status in adult men and women irrespective of DHA baseline status or supplementation dose, but its usefulness in other population subgroups is unclear.

CONCLUSION

There appears to be a range of useful biomarkers of DHA status in humans, but further research is needed to characterize which work best in particular population subgroups.

Modified egg as a nutritional supplement during peak brain development: a new target for fortification

BACKGROUND

Though eggs have the unique capacity, like breastmilk, to concentrate essential nutrients required for early growth and brain development of offspring - i.e. n-3 PUFA, increasingly deficient and sources contaminated - cholesterol and allergy concerns often exclude them from perinatal recommendations.

OBJECTIVE

Egg's potential contribution of key nutrients required for peak brain development are re-evaluated vis-à-vis fortification, accessibility, and risks.

METHODS

Contributions of standard (USDA) and fortified (selected market-available) egg compositions to perinatal requirements for critical brain-supporting nutrients were compared to human and cow milks, and risks and recommendations evaluated.

RESULTS

Standard egg has already higher concentrations/kcal of iron, selenium, zinc, choline, vitamins B12 and E, and essential amino acids (plus taurine) than human milk. Fortified egg could further yield significant n-3 PUFA % recommendations for pregnancy-lactation (total n-3 69.6-75.0% [DRI=1400-1300 mg/day]), including DHA (120.1-129.3%, mostly approximately 80% [calculated DRI=140-130 mg/day]), plus antioxidant vitamins A (9.0-15.2%) and E (51.6-65.3%), and minerals iodine (33.6-44.5%) and selenium (33.7-39.3%); % recommendations for children (1-3 y) even more. Cholesterol, important for nerve membranes and learning, may not be generally contraindicated in childbearing-aged women (approximately 10.5% hypercholesterolemia), and early-life egg exposure may increase tolerance. Egg-inclusive perinatal nutrition programs have shown significant contributions.

CONCLUSIONS

Eggs, especially target-fortified, may provide a unique nutritional supplement for peak brain development continously during pregnancy, nursing, and infancy (from 6 months), especially vs. insufficiencies. Missing nutritional opportunities by egg exclusion vs. concerns of hypercholesterolemia or allergy could be addressed individually, rather than as general recommendations, warranting further research and targeted egg design.

Building the bridges to bioinformatics in nutrition research

Like other life sciences, nutrition science can benefit enormously from the techniques of bioinformatics. In this article, the steps necessary to enable bioinformatic approaches in nutrition research are outlined, from the short-range goal of immediately making data available in ad hoc author-defined formats to the longer range goals of full standardization of nutrition experiments and migration of all experimental data into databases. Several examples of what will be possible for nutrition researchers in this new paradigm are described. Ultimately, nutrition data can be continually recycled to reinvestigate existing hypotheses and to generate new hypotheses that would not have been conceivable at the time of the original experiments. The standardization of experimental designs and the conversion of nutrition data into a machine-readable format will bring about a renaissance in nutrition research, accelerating the ability of investigators to discover the implications of nonessential nutrients and food components, and enable the study of complex metabolic interactions in human health and disease.

Fish oil and mental health: the role of n-3 long-chain polyunsaturated fatty acids in cognitive development and neurological disorders

Epidemiological and experimental studies have indicated that consumption of more n-3 long-chain polyunsaturated fatty acids may reduce the risk for a variety of diseases, including cardiovascular, neurological and immunological disorders, diabetes and cancer. This article focuses on the role of marine n-3 long-chain polyunsaturated fatty acids in brain functions, including the development of the central nervous system and neurological disorders. An overview of the major animal studies and clinical trials is provided here, focusing on fatty acid supplementation during pregnancy and infancy, and prevention and management of Alzheimer's disease, schizophrenia, depression and attention deficit hyperactive disorder. Although an optimal balance in n-3/n-6 long-chain polyunsaturated fatty acid ratio is important for proper neurodevelopment and cognitive functions, results from randomized controlled trials are controversial and do not confirm any useful effect of supplementation on development of preterm and term infants. The relationship between fatty acid status and mental disorders is confirmed by reduced levels of n-3 long-chain polyunsaturated fatty acids in erythrocyte membranes of patients with central nervous system disorders. Nevertheless, there are very little data supporting the use of fish oil in those patients. The only way to verify whether n-3 long-chain polyunsaturated fatty acids are a potential therapeutic option in the management and prevention of mental disorders is to conduct a large definitive randomized controlled trials similar to those required for the licensing of any new pharmacological treatment.

Supplementation of n-3 fatty acids during pregnancy and lactation reduces maternal plasma lipid levels and provides DHA to the infants

OBJECTIVE

Docosahexaenoic acid (DHA, 22:6 n-3) is considered an essential fatty acid for the fetus and newborn infant, but the optimal level of supply is not known. We studied the effect of supplementing pregnant and lactating women with marine n-3 polyunsaturated fatty acids (PUFAs) as compared to n-6 PUFAs related to maternal and infant lipid levels.

STUDY DESIGN

Five hundred and ninety pregnant women in weeks 17-19 of pregnancy were recruited. They were given either 10 mL cod liver oil (n-3 PUFAs) or corn oil (n-6 PUFAs) daily until three months after delivery, and 341 women took part in the study until giving birth.

RESULTS

Maternal supplementation with cod liver oil increased the concentration of DHA in maternal as well as infant plasma and umbilical tissue phospholipids, as compared to corn oil. The maternal plasma triacylglycerol increase during pregnancy was less pronounced in women supplemented with cod liver oil as compared to corn oil. The concentration of high-density lipoprotein (HDL)-cholesterol was unchanged during pregnancy in the cod liver oil group, whereas it decreased in the corn oil group, promoting a greater increase in the ratio of total cholesterol/HDL-cholesterol in the corn oil group.

CONCLUSION

Maternal supplementation with n-3 fatty acids during pregnancy and lactation provides more DHA to the infant and reduces maternal plasma lipid levels compared to supplementation with n-6 fatty acids.

Reducing exposure to dioxins and related compounds through foods in the next generation

Dioxins and related compounds are undesirable and unintended contaminants in the food supply, and dietary intake is the major route of exposure. Reducing dietary exposure to dioxins among the most vulnerable segments of the population (i.e., pregnant women, infants, and young girls) is an effective strategy for reducing body burdens in future generations. Exposure to dioxins through foods can be minimized by selecting lower-fat versions of meats, poultry, and dairy products. Consuming all foods, including fatty fish, in recommended amounts is congruent with the goal of reducing dioxin intake exposure and maintaining good health.

Effect of n-3 long-chain polyunsaturated fatty acid supplementation of women with low-risk pregnancies on pregnancy outcomes and growth measures at birth: a meta-analysis of randomized controlled trials

BACKGROUND

It is hypothesized that the intake of long-chain polyunsaturated fatty acids (LC-PUFAs) throughout pregnancy is important to maternal health and fetal and infant development.

OBJECTIVE

The objective was to evaluate systematically the effect of LC-PUFA supplementation of pregnant women's diets on pregnancy outcomes and growth measures at birth.

DESIGN

We searched MEDLINE, EMBASE, CINAHL, and the Cochrane Library through August 2005 and also searched the references in reviewed articles for randomized controlled trials (RCTs) comparing LC-PUFA supplementation with placebo or no supplementation.

RESULTS

Of 6 included RCTs, only 1 was judged to be at low risk of bias. Supplementation with n-3 LC-PUFAs in these 6 RCTs (1278 infants) was associated with a significantly greater length of pregnancy [weighted mean difference (WMD): 1.57 d; 95% CI: 0.35, 2.78 d; findings stable on sensitivity analysis] than in control subjects. We found no evidence that supplementation influenced the percentage of preterm deliveries, the rate of low-birth-weight infants, or the rate of preeclampsia or eclampsia. We found no significant difference in the 6 RCTs (1278 infants) in birth weight (WMD: 54 g; 95% CI: -3.1, 111 g) and no significant difference in 5 RCTs (1262 infants) in birth length (WMD: 0.23 cm; 95% CI: -0.04, 0.5 cm), but, in 4 RCTs (729 infants), there was a significant increase in head circumference (WMD: 0.26 cm; 95% CI: 0.02, 0.49 cm; significance was lost on sensitivity analysis).

CONCLUSIONS

n-3 LC-PUFA supplementation during pregnancy may enhance pregnancy duration and head circumference, but the mean effect size is small. The implications of these findings for later growth and development remain to be elucidated.