Evidence regarding an effect of marine n-3 fatty acids on preterm birth: a systematic review and meta-analysis

The supplementation of a high dose of fish oil during pregnancy and lactation led to an elevation in Mfsd2a expression without any changes in docosahexaenoic acid levels in the retina of healthy 2-month-old mouse offspring

Introduction

During fetal development, the proper development of neural and visual systems relies on the maternal supplementation of omega-3 fatty acids through placental transfer. Pregnant women are strongly advised to augment their diet with additional sources of omega-3, such as fish oil (FO). This supplementation has been linked to a reduced risk of preterm birth, pre-eclampsia, and perinatal depression. Recently, higher doses of omega-3 supplementation have been recommended for pregnant women. Considering that omega-3 fatty acids, particularly docosahexaenoic acid (DHA), play a crucial role in maintaining the delicate homeostasis required for the proper functioning of the retina and photoreceptors the effects of high-dose fish oil (FO) supplementation during pregnancy and lactation on the retina and retinal pigmented epithelium (RPE) in healthy offspring warrant better understanding.

Methods

The fatty acid content and the changes in the expression of the genes regulating cholesterol homeostasis and DHA transport in the retina and RPE were evaluated following the high-dose FO supplementation.

Results

Our study demonstrated that despite the high-dose FO treatment during pregnancy and lactation, the rigorous DHA homeostasis in the retina and RPE of the two-month-old offspring remained balanced. Another significant finding of this study is the increase in the expression levels of major facilitator superfamily domain-containing protein (Mfsd2a), a primary DHA transporter. Mfsd2a also serves as a major regulator of transcytosis during development, and a reduction in Mfsd2a levels poses a major risk for the development of leaky blood vessels.

Conclusion

Impairment of the blood-retinal barrier (BRB) is associated with the development of numerous ocular diseases, and a better understanding of how to manipulate transcytosis in the BRB during development can enhance drug delivery through the BRB or contribute to the repair of central nervous system (CNS) barriers.

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.

Maternal fish and shellfish consumption and preterm birth: a retrospective study in urban China

Preterm birth is the leading cause of perinatal mortality and morbidity. Some prospective cohort studies suggested that fish and shellfish consumption may affect the incidence of preterm birth. However, conflicting evidence exists on the relationship between fish and shellfish consumption and preterm birth. A total of 10 179 women from Gansu province were interviewed after delivery to collect information on their past intake of fish and shellfish using FFQ. Logistic regression models were used to estimate OR and 95 % CI to examine the association between fish and shellfish consumption and preterm birth and its clinical subtypes. Fish and shellfish consumption was associated with reduced risk of preterm birth (OR = 0·65, 95 % CI 0·56, 0·77). Increasing frequency of fish and shellfish consumption, compared with no fish and shellfish consumption, was associated with decreasing odds of preterm birth. Besides, increasing weekly total amount of fish and shellfish consumption, compared with no fish and shellfish consumption, was also associated with decreasing odds of preterm birth. Significant trend effect was also seen between fish and shellfish consumption and very preterm birth (P_{for trend} = 0·001) and spontaneous preterm birth (P_{for trend} = 0·003). Interaction was observed between total fish and shellfish consumption with maternal age (P_{for interaction} = 0·041) and pre-pregnancy BMI underweight (P_{for interaction} = 0·012). Our findings showed that maternal fish and shellfish consumption was associated with lower incidence of preterm birth.We recommend for the national guideline of ≥350 g/week of fish and shellfish consumption among pregnant women.

Effectiveness of Integrated Maternal Nutrition Intervention Package on Birth Weight in Rwanda

Inadequate maternal nutrition before and during pregnancy is a principal risk factor for poor fetal development, resulting in low birth weight (LBW) and subsequently, poor child growth. Most studies focus on the impact of nutritional interventions after birth while only a few interventions consider integrated nutrition service packages. Therefore, there is limited evidence on whether integrated maternal nutrition interventions have a positive effect on birthweight. Thus, a post-program quasi-experimental study was carried out to determine the effectiveness of the integrated maternal nutrition intervention package on low birth weight in Rwanda. A total of 551 mother–baby pairs from the intervention and 545 controls were included in the analysis. Data regarding socio-demographic, maternal anthropometric parameters, and dietary diversity were collected using a structured questionnaire. Birth weight was assessed right after delivery, within 24 h. Logistic regression, linear regression, and path analysis were fitted to determine the effectiveness of the intervention on birth weight. The study found that the intervention reduced LBW by 66.99% (p < 0.001) and increased average birth weight by 219 g (p < 0.001). Logistic regression identified reduced risk of LBW among the intervention group (AOR = 0.23; 95%CI = 0.12–0.43; p < 0.001). It was also observed that the direct effect of the intervention on birth weight was 0.17 (β = 0.17; p < 0.001) and the main indirect mediator was maternal MUAC (β = 0.05; p < 0.001). Moreover, maternal passive smoking exposure and MUAC < 23 cm were found as risk factors for LBW. This study has demonstrated that an integrated maternal nutritional intervention package can significantly reduce LBW in low-income settings and should, therefore, be considered to improve birth weight.

Interventions for the prevention of spontaneous preterm birth: a scoping review of systematic reviews

BACKGROUND

Globally, 11% of babies are born preterm each year. Preterm birth (PTB) is a leading cause of neonatal death and under-five mortality and morbidity, with lifelong sequelae in those who survive. PTB disproportionately impacts low/middle-income countries (LMICs) where the burden is highest.

OBJECTIVES

This scoping review sought to the evidence for interventions that reduce the risk of PTB, focusing on the evidence from LMICs and describing how context is considered in evidence synthesis.

DESIGN

We conducted a scoping review, to describe this wide topic area. We searched five electronic databases (2009-2020) and contacted experts to identify relevant systematic reviews of interventions to reduce the risk of PTB. We included published systematic reviews that examined the effectiveness of interventions and their effect on reducing the risk of PTB. Data were extracted and is described narratively.

RESULTS

139 published systematic reviews were included in the review. Interventions were categorised as primary or secondary. The interventions where the results showed a greater effect size and consistency across review findings included treatment of syphilis and vaginal candidiasis, vitamin D supplementation and cervical cerclage. Included in the 139 reviews were 1372 unique primary source studies. 28% primary studies were undertaken in LMIC contexts and only 4.5% undertaken in a low-income country (LIC) Only 10.8% of the reviews sought to explore the impact of context on findings, and 19.4% reviews did not report the settings or the primary studies.

CONCLUSION

This scoping review highlights the lack of research evidence derived from contexts where the burden of PTB globally is greatest. The lack of rigour in addressing contextual applicability within systematic review methods is also highlighted. This presents a risk of inappropriate and unsafe recommendations for practice within these contexts. It also highlights a need for primary research, developing and testing interventions in LIC settings.

Effects of prenatal nutrient supplementation and early life exposures on neurodevelopment at age 10: a randomised controlled trial - the COPSYCH study protocol

INTRODUCTION

Nutrient deficiency and immune and inflammatory disturbances in early life may compromise neurodevelopment and be implicated in the aetiology of psychiatric disorders. However, current evidence is limited by its predominantly observational nature. COpenhagen Prospective Study on Neuro-PSYCHiatric Development (COPSYCH) is a research alliance between Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) and Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research with the overall aim to investigate effects of prenatal and early life exposures on neurodevelopment at 10 years. COPSYCH will investigate the impact of prenatal n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) and high-dose vitamin D supplementation on neurodevelopment reflected by brain development, neurocognition and psychopathology. Moreover, the neurodevelopmental impact of early life exposures such as infections, low grade inflammation and the gut microbiome will be scrutinised.

METHODS AND ANALYSIS

COPSYCH is based on the prospective and ongoing COPSAC2010 birth cohort of 700 mother-child pairs. Randomised controlled trials of supplementation with n-3 LCPUFA and/or high-dose vitamin D or placebo in the third trimester were embedded in a factorial 2×2 design (ClinicalTrials.gov: NCT01233297 and NCT00856947). This unique cohort provides deep phenotyping data from 14 previous clinical follow-up visits and exposure assessments since birth. The ongoing 10-year visit is a 2-day visit. Day 1 includes a comprehensive neurocognitive examination, and assessment of psychopathological dimensions, and assessment of categorical psychopathology. Day 2 includes acquisition of brain structural, diffusion and functional sequences using 3 Tesla MRI. Study outcomes are neurocognitive, psychopathological and MRI measures.

ETHICS AND DISSEMINATION

This study has been approved by the Danish National Committee on Health Research Ethics and The Danish Data Protection Agency. The study is conducted in accordance with the guiding principles of the Declaration of Helsinki. Parents gave written informed consent before enrolment.

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.

Maternal Blood Pressure in Relation to Prenatal Lipid-Based Nutrient Supplementation and Adverse Birth Outcomes in a Ghanaian Cohort: A Randomized Controlled Trial and Cohort Analysis

BACKGROUND

It is unknown whether prenatal lipid-based nutrient supplements (LNSs) affect blood pressure (BP). Associations between hypertension and birth outcomes using recently updated BP cutoffs are undetermined.

OBJECTIVES

We aimed to assess the impact of LNSs on maternal hypertension and associations between hypertension and birth outcomes.

METHODS

Pregnant Ghanaian women at ≤20 weeks of gestation (n = 1320) were randomly assigned to receive daily 1) iron and folic acid (IFA), 2) multiple micronutrients (MMN), or 3) LNSs until delivery. BP was measured at enrollment and 36 weeks of gestation. We analyzed the effect of LNSs on BP using ANOVA and associations between hypertension [systolic BP (SBP) ≥130 mm Hg or diastolic BP (DBP) ≥80 mm Hg] and birth outcomes by linear and logistic regressions.

RESULTS

Mean ± SD SBP and DBP were 110 ± 11 and 63 ± 8 mm Hg at 36 weeks of gestation and did not differ by supplementation group (SBP, P > 0.05; DBP, P > 0.05). At enrollment, higher DBP was associated with lower birth weight and shorter gestation; women with high DBP had greater risk of low birth weight (LBW) [risk ratio (RR): 2.58; 95% CI: 1.09, 6.08] and preterm birth (PTB) (RR: 3.30; 95% CI: 1.47, 7.40). At 36 weeks of gestation, higher SBP was associated with lower birth weight, length, and head circumference and shorter gestation; higher DBP was associated with lower birth weight and length; and women with high DBP had greater risk of LBW (RR: 3.39; 95% CI: 1.32, 8.69). Neither high SBP nor hypertension were associated with birth outcomes at either time point.

CONCLUSIONS

Daily provision of LNSs does not affect maternal hypertension, compared with IFA and MMN. Higher SBP and DBP are associated with a shorter gestation and smaller birth size; however, only high DBP is associated with LBW and PTB. The new BP cutoffs may help identify pregnancies at risk of adverse birth outcomes.This trial was registered at clinicaltrials.gov as NCT00970866.

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).

Maternal Supplementation with Polyphenols and Omega-3 Fatty Acids during Pregnancy: Effects on Growth, Metabolism, and Body Composition of the Offspring

Simple Summary

The present study aimed to determine benefits and risks of a dietary supplementation combining hydroxytyrosol and n3 polyunsaturated fatty acids (PUFA) on developmental patterns and metabolic traits of offspring in swine, a model of intrauterine growth restricted (IUGR) pregnancies. There were no deleterious effects on the reproductive traits of the sows and the postnatal features of the piglets. Piglets from the supplemented sows, in spite of a lower mean weight and corpulence at birth, showed higher average daily weight gain and fractional growth rate afterwards. Consequently, they reached higher weight and corpulence with increased muscle development and better lipidemic and fatty acids profiles than control offspring at juvenile stages.

Abstract

Maternal supplementation with antioxidants and n3 PUFAs may be a promising strategy to reduce the risk of intrauterine growth restriction and preterm delivery, which may diminish the appearance of low-birth-weight neonates. The present study aimed to determine benefits and risks of a dietary supplementation combining hydroxytyrosol, a polyphenol from olive leaves and fruits, and n3 PUFAs, from linseed oil, on developmental patterns and metabolic traits of offspring in swine, a model of IUGR pregnancies. The results obtained indicate that maternal supplementation with hydroxytyrosol and n-3 fatty acids during pregnancy has no deleterious effects on the reproductive traits of the sows (prolificacy, homogeneity of the litter, and percentage of stillborns and low-birth-weight, LBW, piglets) and the postnatal features of the piglets (growth patterns, adiposity, and metabolic traits). Conversely, in spite of a lower mean weight and corpulence at birth, piglets from the supplemented sows showed higher average daily weight gain and fractional growth rate. Thus, at juvenile stages afterwards, the offspring from the treated group reached higher weight and corpulence, with increased muscle development and better lipidemic and fatty acid profiles, in spite of similar adiposity, than offspring in the control group. However, much caution and more research are still needed before practical recommendation and use in human pregnancies.

Safety and efficacy of supplements in pregnancy

Pregnancy is a time where expectant mothers often focus on their diet to improve their own health and to preserve the future health of their children. There is much conflicting information in the public domain about the safety and/or efficacy of nutritional supplements during pregnancy. Despite this, the market for supplements is growing. This review discusses the roles of critical nutrients in pregnancy and the available evidence on the use of supplements to reduce risks and improve maternal and fetal outcomes. Recommendations are made for pregnant women, taking into account safety data and tolerable upper intakes set for pregnant women. It is important for dieticians, nutritionists, physicians, and other healthcare providers to be able to offer accurate and evidence-based advice on supplement use in pregnancy. Routine supplementation may not be necessary for all, but individuals at risk are identified.

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.

Prevention of preterm birth: Proactive and reactive clinical practice-are we on the right track?

Preterm birth remains the major cause of death and disability among children under the age of five. In developing countries antenatal preterm birth prevention clinics are set up to provide cervical length surveillance and/or treatment modalities such as cerclage or progesterone for those women with identified risk factors such as previous cervical treatment or preterm birth. However, 85% of women have no risk factors for PTB and currently there is no biomarker to screen women early in pregnancy. Women will present unexpectedly in threatened preterm labour and we have no choice but to adopt a re-active approach to their care by using predication and preparation strategies such as fetal fibronectin, tocolytic therapy and steroids. Despite these strategies approximately 15-20% of these women will give birth preterm before 34 weeks. There is a urgent need to re-design primary, secondary and tertiary prevention strategies for spontaneous preterm labour (sPTL) in singleton pregnancies aimed at identifying and addressing key gaps in clinical practice and research.

The Relationship of Nutritional Energy and Macronutrient Intake with Pregnancy Outcomes in Czech Pregnant Women

Maternal nutrition and metabolism play important roles for the well-being of both mother and fetus during pregnancy. This longitudinal study brings an original evaluation of the relationship between the nutritional energy and macronutrients intake (NEMI) and pregnancy outcomes and an assessment of the changes in such intake over the previous ten years. Sixty-five healthy Czech pregnant women were examined in three pregnancy periods (1st: 17th-27th; 2nd: 28th-35th; 3rd: 36th-38th gestational weeks). Results of 7-day dietary records were analyzed using NutriDan software. Energy intake decreased from 30.0 kcal/kg to 25.0 kcal/kg during pregnancy. The data also showed a decrease in macronutrients intake (p < 0.0001) with the advancing stage of pregnancy. Positive correlations were demonstrated between NEMI and birth weight (r = 0.410, p < 0.001). In the second pregnancy period, NEMI (excluding carbohydrates) positively associated with neonatal birth length (p < 0.01) and negatively with duration of birth (p < 0.05). An increased NEMI in the last period of pregnancy shortened the length of pregnancy.

Reducing the Risk of Preterm Birth by Ambulatory Risk Factor Management

BACKGROUND

The preterm birth rate in Germany has remained unchanged at 8-9% since 2009. Preterm birth is the most common cause of neonatal morbidity and mortality. In the absence of a causal treatment, it is important to lower the risk of preterm birth by preventive measures in prenatal outpatient care.

METHODS

This review is based on pertinent publications from the years 2000-2019 that were retrieved by a selective search in PubMed.

RESULTS

The clinical risk factors for preterm birth-known mainly from retrospective cohort studies-include previous preterm birth (adjusted odds ratio [aOR]: 3.6), multiple pregnancy (relative risk [RR]: 7.7), nicotine consumption (aOR: 1.7), and a short uterine cervix, i.e., <25 mm in the second trimester (aOR: 6.9). In women with a short cervix, vaginally administered progesterone significantly lowers the preterm birth rate (22.5% vs. 14.1% for birth before 33 weeks of gestation, RR: 0.62; 95% confidence interval [0.47; 0.81]). Nicotine abstinence is associated with a lower pre- term birth rate as well (aOR: 0.91; [0.88; 0,.94]), while working more than 40 hours per week (aOR: 1.25; [1,.01; 1,.54]) and heavy lifting during pregnancy (hazard ratio [HR]: 1.43; [1.13; 1.80]) are associated with a higher preterm birth rate. Avoidance of physical exertion, or bed rest, in the face of impending preterm birth does not lower the preterm birth rate, but it does increase the risk of complications, such as thromboembolism.

CONCLUSION

The meticulous assessment and elimination of treatable risk factors at the outset of ambulatory prenatal care can help lower the preterm birth rate. Further velopment of causally directed treat- ments (e.g., changes of relevant environmental and epigenetic factors).

Spontaneous preterm labour that leads to preterm birth: An update and personal reflection

OBJECTIVE

The objective was to provide an update of progress made over time (including personal reflection) of our attempts to reduce the mortality and morbidity associated with spontaneous preterm labour that leads to preterm birth.

METHODS

An experienced and evidence based approach was taken to provide an overview of progress made over a generation (∼40 years) in our understanding of spontaneous preterm labour.

RESULTS

It is evident that we have made significant progress in our understanding of the aetiology, the measurement of the burden, the basic science, systems biology and mechanical pathways of the preterm parturition syndrome. We have better ways of predicting, preventing and managing spontaneous preterm labour than existed a generation ago.

CONCLUSIONS

The profile of spontaneous preterm labour that leads to preterm birth, thanks to organisations such as the March of Dimes, WHO and PREBIC is much more evident than before. However, while we have come a long way, we must not be complacent, and clinicians and basic scientists must continue to work in harmony, while recruiting and encouraging young investigators to join the effort to improve survival and handicap in what is one of the Great Obstetric Syndromes.

Effect of n-3 long-chain polyunsaturated fatty acids supplementation in healthy mothers on DHA and EPA profiles in maternal and umbilical blood: a randomized controlled trial

Background The objective of the study was to compare the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) dietary supplementation on their concentration in total lipids (TL) and lipid fractions of maternal and umbilical vein (UV) blood. The specific objective was to analyze the impact of EPA and DHA supplementation on pregnancy outcome and neonatal birth weight. Methods Women were randomly single-blinded (randomized controlled trial; ISRCTN36705743) allocated to the group receiving EPA and DHA supplementation (supplemented group) or the group receiving placebo-corn oil (control group) in the time period from January 1st, 2016 until March 1st, 2017. Women in the supplemented group (n=45) took 360 mg EPA and 240 mg DHA daily while controls (n=42) were given a placebo. Maternal and UV bloods were obtained at delivery. After lipid extraction, phospholipids (PL), cholesterol esters (CE), triacylglycerols (TG) and non-esterified fatty acids were separated by thin layer chromatography and analyzed by gas chromatography. Results Higher DHA concentrations in TL (37.24±21.87 mg/L), PL (13.14±8.07 mg/L) and triacylglycerols (2.24±2.21 mg/L) were recorded in mothers from the supplemented group when compared to the study group (TL 21.89±14.53 mg/L; P<0.001; PL 9.33±5.70 mg/L; P=0.013; TG 0.56±0.43 mg/L; P<0.001). Higher DHA concentrations in UV samples were found in TL (11.51±7.34 mg/L), PL (5.29±3.31 mg/L) and triacylglycerols (0.62±0.46 mg/L) from the supplemented groups compared with controls (TL 7.37±3.60 mg/L; P=0.002; PL 3.52±2.19 mg/L; P=0.005; TG 0.40±0.46 mg/L; P=0.035). The ratio of AA:DHA was lower in maternal (2.43) and UV serum (4.0) of the supplemented group than in the control group (maternal 3.85 P<0.001; UV 4.91 P<0.001). Conclusion The study demonstrated the higher ratio of AA/DHA in the control group indicating that pregnant women on the traditional Herzegovina diet need supplementation with DHA and EPA.

Importance of n-3 PUFA consumption during pregnancy: perception discrepancies between pregnant women and gynaecologists-obstetricians in Belgium

OBJECTIVE

n-3 PUFA during pregnancy have been subject to intense research interest, but also much controversy, creating a situation of confusion among patients and health-care providers. The present study was carried out to explore knowledge, attitude and practices regarding n-3 PUFA in two independent populations of pregnant women and gynaecologists-obstetricians in Belgium and to assess the relationship between the pregnant women's attributes and their n-3 PUFA status measured by the omega-3 index.

DESIGN

Cross-sectional study. Knowledge, attitude and practices were collected by self-administered questionnaires while laboratory data were available for each pregnant woman.

SETTING

During the first antenatal hospital appointment (for the pregnant women) and by email (for the gynaecologists-obstetricians).ParticipantsWomen in early pregnancy (n 122) and gynaecologists-obstetricians (n 67).

RESULTS

Marked discrepancies in perception were evidenced between the pregnant women and health-care providers. While 82 % of the women attached high importance to n-3 PUFA during pregnancy, only a third of the gynaecologists-obstetricians did. About 35 % of the women declared paying particular attention to their consumption of n-3 PUFA. After adjusting for sociodemographic characteristics, these positive dietary practices were significantly associated with higher omega-3 index (P=0·04). Overall, 43·3 % of professionals did not provide any information about n-3 PUFA to their pregnant patients and 46·3 % did not take any preventive actions.

CONCLUSIONS

Evidence-based guidelines, refreshment training and communication tools are needed to improve awareness and clinical practices among caregivers regarding n-3 PUFA to benefit both mothers and their children.

Omega-3 polyunsaturated fatty acids reduce preterm labor by inhibiting trophoblast cathepsin S and inflammasome activation

Preterm labor is associated with inflammation and infection. The mechanisms underlying the role of omega-3 fatty acid in inflammasome activation and prevention of preterm labor remain unknown. We hypothesized that omega-3 fatty acid can reduce the rate of preterm birth induced by infection and trophoblast inflammation. In the present study, we found that inflammasome-related molecules and IL-1β in trophoblasts were activated by TNF-α derived from lipopolysaccharide (LPS)-stimulated THP-1 cell-conditioned medium (CM) and recombinant TNF-α protein. The results demonstrated that stimulation with TNF-α caused lysosomal rupture in trophoblasts, which accelerated cathepsin S (CTSS) diffusion from lysosomes to the cytosol and activated NLRP1 (nacht domain-leucine-rich repeat, and pyd-containing protein 1) and absent in melanoma 2 (AIM2) inflammasomes, thereby increasing IL-1β secretion. Moreover, in response to LPS challenge, TNF-α increased trophoblast cell death and decreased cell viability through inflammasome and CTSS activation. Stearidonic acid (SDA; 18:4n-3) and docosahexaenoic acid (DHA; 22:6n-3) inhibited inflammasome-related molecule synthesis and CTSS and caspase-1 activation, which further reduced the preterm delivery rate of pregnant mice induced by LPS (92.9 compared with 69.7% (DHA); 92.9 compared with 53.5% (SDA)). Higher expression of TNF-α, IL-1β, prostaglandin E2, and CTSS, but lower resolvin D1 expression, was observed in preterm pregnant mice than in controls. Similarly, resolvin D1 was highly expressed in women with term delivery compared with women with preterm delivery. Thus, SDA and DHA may attenuate macrophage-derived TNF-α inducing CTSS and inflammasome activation, IL-1β secretion, and placental trophoblast cell death. These functions are implicated in the preventive effects of SDA and DHA on preterm labor.

Marine Omega-3 Fatty Acids, Complications of Pregnancy and Maternal Risk Factors for Offspring Cardio-Metabolic Disease

Marine omega-3 polyunsaturated fatty acids (n-3 PUFA) are important nutrients during periods of rapid growth and development in utero and infancy. Maternal health and risk factors play a crucial role in birth outcomes and subsequently offspring cardio-metabolic health. Evidence from observational studies and randomized trials have suggested a potential association of maternal intake of marine n-3 PUFAs during pregnancy with pregnancy and birth outcomes. However, there is inconsistency in the literature on whether marine n-3 PUFA supplementation during pregnancy can prevent maternal complications of pregnancy. This narrative literature review summarizes recent evidence on observational and clinical trials of marine n-3 PUFA intake on maternal risk factors and effects on offspring cardio-metabolic health. The current evidence generally does not support a role of maternal n-3 PUFA supplementation in altering the incidence of gestational diabetes, pregnancy-induced hypertension, or pre-eclampsia. It may be that benefits from marine n-3 PUFA supplementation are more pronounced in high-risk populations, such as women with a history of complications of pregnancy, or women with low marine n-3 PUFA intake. Discrepancies between studies may be related to differences in study design, dosage, fatty acid interplay, and length of treatment. Further prospective double-blind studies are needed to clarify the impact of long-chain marine n-3 PUFAs on risk factors for cardio-metabolic disease in the offspring.

Maternal obesity-induced decreases in plasma, hepatic and uterine polyunsaturated fatty acids during labour is reversed through improved nutrition at conception

Maternal obesity is associated with prolonged and dysfunctional labour, potentially through decreased synthesis of prostaglandins that stimulate myometrial contractions. We assessed the impact of maternal obesity on concentrations of precursor fatty acids (FA) for prostaglandin synthesis and whether any changes could be reversed by improved nutrition post-conception. Wistar rats were fed control (CON) or High-Fat, High-cholesterol (HFHC) diets 6 weeks before mating. At conception half the dams switched diets providing 4 dietary groups: (1) CON, (2) HFHC, (3) CON-HFHC or (4) HFHC-CON. During parturition rats were euthanized and FA composition of plasma, liver and uterus determined. Visceral fat was doubled in rats exposed to the HFHC diet prior to and/or during pregnancy compared to CON. HFHC diet increased MUFAs but decreased omega-3 and omega-6 PUFAs in plasma and liver. Uterine omega-3 FA concentrations were halved in HFHC versus CON rats, but all other FAs were similar. Switching from HFHC to CON diet at conception restored all FA profiles to those seen in CON rats. The increased MUFA and decreased PUFA concentrations in obese HFHC dams may contribute to aberrant prostaglandin synthesis and dysfunctional myometrial activity and it may be possible to reverse these changes, and potentially improve labour outcomes, by improving nutrition at conception.

Maternal obesity, fish intake, and recurrent spontaneous preterm birth

OBJECTIVE

Moderate fish intake in early pregnancy is associated with decreased risk of preterm birth (PTB). Obesity during pregnancy is characterized by inflammation and insufficiency of essential fatty acids. The objective of this study was to measure the association between fish intake during pregnancy and risk of recurrent spontaneous (s) PTB among lean, overweight, and obese women.

DESIGN

This is secondary analysis of a randomized controlled trial of omega-3 fatty acid supplementation for recurrent PTB prevention, 2005-2006. The primary exposure was fish intake at time of enrollment (16-22.9-week gestation). The primary outcomes were sPTB <37 weeks and sPTB <35 weeks. Maternal prepregnancy body mass index was treated as an effect modifier.

SUBJECTS

Eight hundred and fifty-two women were included, 47% were lean, 25% overweight, and 28% obese.

RESULTS

In this cohort, among lean, but not overweight or obese women, ≥1 serving of fish per week was associated with decreased frequency of sPTB <37 weeks compared with <1 serving of fish per week (45.1% versus 27.5%, p = .001) and spontaneous PTB <35 (21.4% versus 11.6%, p = .01). In adjusted models, as fish intake increased, the predicted probability of sPTB decreased in lean women but increased in overweight and obese women (p for interaction < .10).

CONCLUSION

Fish intake was associated with lower probability of sPTB in lean women and higher probability in obese women. These findings warrant further investigation to understand the dietary or metabolic factors associated with obesity that may modulate benefit of fish intake during pregnancy.

The effect of fish oil supplementation on maternal and neonatal outcomes: a triple-blind, randomized controlled trial

OBJECTIVE

To evaluate the effect of fish oil supplementation on pregnancy outcomes in mother and newborn.

METHODS

This randomized, triple-blind, placebo-controlled trial was conducted on 150 pregnant women aged 18-35 years from Feburary 2014 to April 2015 in Tabriz, Iran. Participants were assigned to receive either 1000 mg fish oil supplements containing 180 mg eicosapentaenoic acid (EPA) and 120 mg docosahexanoic acid or placebo from week 20 of gestation to birth. The primary outcome measure was birth weight. Gestational duration, preterm labor low birth weight (LBW), length, head circumference, and maternal serum docosahexaenoic acid (DHA) and EPA level at 35-37 weeks were also examined. The statistical analysis was on an intention-to-treat basis.

RESULTS

Demographic characteristics were similar in both groups (P>0.05). The mean (SD) birth weight values in the fish oil and placebo groups were 3256 (362) g and 3172 (447) g, respectively (adjusted mean difference (MD)=84.1 g, 95% confidence interval [CI]=-24.8 to 193.2). Five (7.6%) neonates in the placebo versus no case in the fish oil group were born with LBW (P=0.02). The rate of preterm labor was lower in the fish oil group (adjusted OR=0.74, 95% CI=0.16-3.42). However, there were no statistically significant differences in the maternal outcomes (P>0.05) with the exception of the proportion of maternal serum DHA fatty acid at 35-37 weeks (P<0.001).

CONCLUSION

Although low dose fish oil supplementation increased birth weight, its effect was not statistically significant. The frequency of LBW was significantly reduced in the intervention group, but the observed reduction needs to be confirmed in future larger investigations using different doses of omega-3.

DHA supplementation during pregnancy as phospholipids or TAG produces different placental uptake but similar fetal brain accretion in neonatal piglets

The great variety of n-3 long-chain PUFA sources raises the question of the most adequate for using as a DHA supplement during pregnancy. Placental and fetal availability of different DHA sources remains unclear. We investigated DHA availability in maternal lipoproteins, placenta and fetal tissues in pregnant sows fed DHA as phospholipid (PL) or TAG to identify the best DHA source during this period. Pregnant Iberian sows were fed diets containing 0·8 % DHA of total fatty acids as PL from egg yolk or TAG from algae oil during the last third of gestation (40 d). Maternal tissues, placentas and fetal tissues were obtained at delivery and DHA quantified by GC. Major Facilitator Superfamily Domain Containing 2a (MFSD2a) carrier expression was analysed in both placenta and fetal brain by Western blotting. Sows fed the DHA–PL diet showed higher DHA incorporation in plasma LDL but not in plasma total lipids. No differences were found in DHA content between groups in maternal liver, adipose tissue or brain. Placental tissue incorporated more DHA in both total lipids and PL fraction in sows fed DHA–PL. However, this did not lead to an enhanced DHA accretion either in fetal plasma, fetal liver or fetal brain. MFSD2a expression was similar between both experimental groups. Maternal DHA supplementation during pregnancy in sow either as PL or TAG produces similar DHA accretion in fetal tissues but not in placenta. Both fat sources are equally available for fetal brain.

The effect of omega-3 supplementation on pregnancy outcomes by smoking status

BACKGROUND

Smoking during pregnancy is associated with adverse maternal and neonatal outcomes such as preterm delivery, intrauterine growth restriction, stillbirth, and low birth weight. Because smoking causes oxidative stress, some have suggested using antioxidants to counteract the effects of oxidative stress. Smokers have lower serum levels of omega-3 fatty acids, an important antioxidant, and thus, investigating whether omega-3 supplementation in smokers reduces adverse maternal and neonatal outcomes represents an important area of research.

OBJECTIVE

To investigate whether the antioxidant effect of omega-3 fatty acid supplementation on the incidence of adverse pregnancy outcomes differs between smokers and nonsmokers.

STUDY DESIGN

Secondary analysis of a multicenter randomized controlled trial of omega-3 supplementation for preterm delivery prevention in women with a singleton pregnancy and a history of a previous singleton spontaneous preterm delivery. Subjects were randomized to begin omega-3 or placebo before 22 weeks, which was continued until delivery. All women received 17 alpha-hydroxyprogesterone caproate intramuscularly weekly beginning between 16 and 20 weeks of gestation and continued until 36 weeks of gestation or delivery, whichever occurred first. The primary outcome was spontaneous preterm delivery. Secondary outcomes were indicated preterm delivery, any preterm delivery (spontaneous and indicated), pregnancy-associated hypertension (gestational hypertension and preeclampsia), a neonatal composite (retinopathy of prematurity, intraventricular hemorrhage grade III or IV, patent ductus arteriosus, necrotizing enterocolitis, sepsis, respiratory morbidity, or perinatal death), low birth weight (<2500 g), small for gestational age (less than the 10th percentile), and neonatal intensive care unit or intermediate nursery admission. The study population was stratified into smokers and nonsmokers, and the incidence of each outcome was compared by omega-3 supplementation versus placebo in each subgroup. Zelen tests were performed to test for homogeneity of effect in smokers and nonsmokers.

RESULTS

Of 851 subjects included in the analysis, 136 (16%) smoked. Baseline characteristics between omega-3 and placebo groups did not differ in smokers or nonsmokers. Omega-3 supplementation was associated with a lower risk of spontaneous preterm delivery in smokers (relative risk, 0.56, 95% confidence interval, 0.36-0.87) but not in nonsmokers (relative risk 1.04, 95% confidence interval 0.84-1.29); P value for interaction = 0.013. Low birth weight was also less frequent in smokers receiving omega-3 supplementation (relative risk 0.57, 95% confidence interval 0.36-0.90) compared with nonsmokers (relative risk 0.93, 95% confidence interval 0.71-1.24); P value for interaction = 0.047. The effect on other secondary outcomes did not differ significantly between smokers and nonsmokers.

CONCLUSION

Omega-3 supplementation in smokers may have a protective effect against recurrent spontaneous preterm delivery and low birth weight.

Effects of nutrition interventions during pregnancy on low birth weight: an overview of systematic reviews

INTRODUCTION

Low birth weight (LBW, birth weight less than 2500 g) is associated with infant mortality and childhood morbidity. Poor maternal nutritional status is one of several contributing factors to LBW. We systematically reviewed the evidence for nutrition-specific (addressing the immediate determinants of nutrition) and nutrition-sensitive (addressing the underlying cause of undernutrition) interventions to reduce the risk of LBW and/or its components: preterm birth (PTB) and small-for-gestational age (SGA).

METHODS

We conducted a comprehensive literature search in MEDLINE, EMBASE, CINAHL and the Cochrane Database of Systematic Reviews (September 2015). Systematic reviews of randomised controlled trials focusing on nutritional interventions before and during pregnancy to reduce LBW and its components were eligible for inclusion into the overview review. We assessed the methodological quality of the included reviews using A Measurement Tool to Assess Reviews (AMSTAR), PROSPERO: CRD42015024814.

RESULTS

We included 23 systematic reviews which comprised 34 comparisons. Sixteen reviews were of high methodological quality, six of moderate and only one review of low quality. Six interventions were associated with a decreased risk of LBW: oral supplementation with (1) vitamin A, (2) low-dose calcium, (3) zinc, (4) multiple micronutrients (MMN), nutritional education and provision of preventive antimalarials. MMN and balanced protein/energy supplementation had a positive effect on SGA, while high protein supplementation increased the risk of SGA. High-dose calcium, zinc or long-chain n-3 fatty acid supplementation and nutritional education decreased the risk of PTB.

CONCLUSION

Improving women's nutritional status positively affected LBW, SGA and PTB. Based on current evidence, especially MMN supplementation and preventive antimalarial drugs during pregnancy may be considered for policy and practice. However, for most interventions evidence was derived from a small number of trials and/or participants. There is a need to further explore the evidence of nutrition-specific and nutrition-sensitive interventions in order to reach the WHO's goal of a 30% reduction in the global rate of LBW by 2025.

Early pregnancy body mass index modifies the association of pre-pregnancy dietary patterns with serum polyunsaturated fatty acid concentrations throughout pregnancy in Brazilian women

Dietary patterns (DPs) have been described as an important factor that may influence polyunsaturated fatty acid (PUFA) concentrations and body mass index (BMI) during pregnancy. We aim to evaluate the association between pre-pregnancy DPs and serum PUFA percentages throughout pregnancy considering early pregnancy BMI as a possible effect modifier. A prospective cohort of 154 pregnant women was followed (5th-13th, 20th-26th, and 30th-36th gestational weeks). Serum PUFA concentrations (total n-3 and total n-6, eicosapentaenoic + docosahexaenoic acids) were measured in each trimester and expressed as percentages. The n-6/n-3 ratio was calculated. Longitudinal linear mixed-effects models including interaction terms between DPs and early pregnancy BMI were employed. Serum PUFA percentages declined, whereas the n-6/n-3 ratio, monounsaturated, and saturated percentages increased throughout pregnancy for all BMI categories. Three pre-pregnancy DPs were identified by principal component analysis (common Brazilian, healthy, and processed). Overweight women with higher adherence to the common-Brazilian and to the healthy DPs presented reduced n-3 PUFA percentage and increased n-6 percentages and n-6/n-3 ratio compared to under or normal weight women. Obese women with higher adherence to the processed DP presented a more pronounced decrease of total n-3 percentage compared to under or normal weight women. Early pregnancy BMI modified the effect of pre-pregnancy DPs on PUFA profile throughout gestation. Higher adherence to the healthy pattern was associated with increased n-3 percentage, except for overweight women. Only for processed DP was the behaviour of PUFA the same for all BMI categories, showing a worse evolution profile, that is, increased n-6 and reduced n-3 fractions.

Maternal intake of seafood and supplementary long chain n-3 poly-unsaturated fatty acids and preterm delivery

BACKGROUND

Preterm delivery increases the risk of neonatal morbidity and mortality. Studies suggest that maternal diet may affect the prevalence of preterm delivery. The aim of this study was to assess whether maternal intakes of seafood and marine long chain n-3 polyunsaturated fatty acids (LCn-3PUFA) from supplements were associated with preterm delivery.

METHODS

The study population included 67,007 women from the Norwegian Mother and Child Cohort Study. Maternal food and supplement intakes were assessed by a validated self-reported food frequency questionnaire in mid-pregnancy. Information about gestational duration was obtained from the Medical Birth Registry of Norway. We used Cox regression to estimate hazard ratios (HR) with 95% confidence intervals (CI) for associations between total seafood, lean fish, fatty fish, and LCn-3PUFA intakes and preterm delivery. Preterm was defined as any onset of delivery before gestational week 37, and as spontaneous or iatrogenic deliveries and as preterm delivery at early, moderate, and late preterm gestations.

RESULTS

Lean fish constituted 56%, fatty fish 34% and shellfish 10% of seafood intake. Any intake of seafood above no/rare intake (>5 g/d) was associated with lower prevalence of preterm delivery. Adjusted HRs were 0.76 (CI: 0.66, 0.88) for 1-2 servings/week (20-40 g/d), 0.72 (CI: 0.62, 0.83) for 2-3 servings/week (40-60 g/d), and 0.72 (CI: 0.61, 0.85) for ≥3 servings/week (>60 g/d), p-trend <0.001. The association was seen for lean fish (p-trend: 0.005) but not for fatty fish (p-trend: 0.411). The intake of supplementary LCn-3PUFA was associated only with lower prevalence of early preterm delivery (before 32 gestational weeks), while increasing intake of LCn-3PUFA from food was associated with lower prevalence of overall preterm delivery (p-trend: 0.002). Any seafood intake above no/rare was associated with lower prevalence of both spontaneous and iatrogenic preterm delivery, and with lower prevalence of late preterm delivery.

CONCLUSIONS

Any intake of seafood above no/rare consumption was associated with lower prevalence of preterm delivery. The association was stronger for lean than for fatty fish. Intake of supplementary LCn-3PUFA was associated only with early preterm delivery. The findings corroborate the current advice to include fish and seafood as part of a balanced diet during pregnancy.

Pregnancy and Infants' Outcome: Nutritional and Metabolic Implications

Pregnancy is a complex period of human growth, development, and imprinting. Nutrition and metabolism play a crucial role for the health and well-being of both mother and fetus, as well as for the long-term health of the offspring. Nevertheless, several biological and physiological mechanisms related to nutritive requirements together with their transfer and utilization across the placenta are still poorly understood. In February 2009, the Child Health Foundation invited leading experts of this field to a workshop to critically review and discuss current knowledge, with the aim to highlight priorities for future research. This paper summarizes our main conclusions with regards to maternal preconceptional body mass index, gestational weight gain, placental and fetal requirements in relation to adverse pregnancy and long-term outcomes of the fetus (nutritional programming). We conclude that there is an urgent need to develop further human investigations aimed at better understanding of the basis of biochemical mechanisms and pathophysiological events related to maternal-fetal nutrition and offspring health. An improved knowledge would help to optimize nutritional recommendations for pregnancy.

Placental DHA and mRNA levels of PPARγ and LXRα and their relationship to birth weight

BACKGROUND

A very large number of fatty acids play wide range of physiological roles in cellular growth and function in placental as well as fetal growth. However, docosahexaenoic acid (DHA), in addition to its critical role in cellular membranes, is known to act as a ligand for several nuclear receptors and regulates the activity of transcription factor families like peroxisome proliferator-activated receptor, liver X receptor (LXR), retinoid X receptor (RXR), and sterol regulatory element binding protein (SREBP). These transcription factors and DHA are known to regulate the placental and fetal growth and development.

OBJECTIVE

The objective of the present study was to examine the fatty acids and transcription factors in the placenta of women delivering low birth weight (LBW) babies.

METHODS

The present study examines the fatty acid and mRNA levels of various transcription factors in the placentae of women delivering normal birth weight (NBW) (n = 38) and women delivering LBW (n = 36). Placental fatty acids were analyzed using gas chromatography. Placental mRNA levels of PPARα, PPARγ, SREBP-1c, LXRα, RXRα, and RXRγ were examined using quantitative real time PCR.

RESULT

Placental DHA levels and mRNA levels of placental PPARγ and LXRα were lower (P < .05 for all) in women delivering LBW babies. There was a positive association of placental PPARγ mRNA levels and placental DHA levels with baby weight (P < .05 for both).

CONCLUSION

Our data suggest that lower placental DHA and transcription factors may have a vital role in the etiology of LBW babies.

Effects of in utero exposure to polychlorinated biphenyls, methylmercury, and polyunsaturated fatty acids on birth size

The adverse effects of in utero exposure to polychlorinated biphenyls (PCBs) or methylmercury (MeHg), and the beneficial effects of nutrients from maternal fish intake might have opposing influences on fetal growth. In this study, we assessed the effects of in utero exposure to PCBs and MeHg on birth size in the Japanese population, which is known to have a high frequency of fish consumption. The concentrations of PCBs and polyunsaturated fatty acids in maternal blood, and the total mercury in hair (as a biomarker of MeHg exposure) were measured during pregnancy and at delivery. Maternal intakes of fish (subtypes: fatty and lean) and shellfishes were calculated from a food frequency questionnaire administered at delivery. Newborn anthropometric measurement data were obtained from birth records. The associations between chemical exposures and birth size were analyzed by using multiple regression analysis with adjustment for confounding factors among 367 mother-newborn pairs. The birth weight was 3073±37 g (mean±SD). The incidence of babies small for gestational age (SGA) by weight was 4.9%. The median concentrations of total PCBs and hair mercury were 108 ng/g lipid and 1.41 μg/g, respectively. There was no overall association between mercury concentrations and birth weight, birth length, chest circumference, and head circumference. We observed that the risk of SGA by weight decreased with increasing mercury concentration in regression analyses with adjustment for polyunsaturated fatty acids. Our results suggest that the beneficial effect of essential nutrition may mask the adverse effects of MeHg on birth size. The concentrations of PCBs had no association with birth size.

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.

Maternal fish consumption, fatty acid levels and angiogenic factors: The Generation R Study

INTRODUCTION

Angiogenic factors, such as placental growth factor (PlGF) and soluble Flt-1 (sFlt-1), are key regulators of placental vascular development. Evidence from in vitro studies indicates that fatty acids can affect angiogenesis. We investigated the associations of maternal fish consumption and fatty acids levels with angiogenic factors during pregnancy, and in cord blood in a large population-based prospective cohort.

METHODS

First trimester fish consumption was assessed among 3134 pregnant women using a food-frequency questionnaire. Plasma fatty acid levels were measured in second trimester. Plasma PlGF and sFlt-1 were measured in first and second trimester and in cord blood. Associations of fish consumption or fatty acid levels with angiogenic factors were assessed by multivariable linear regression analyses.

RESULTS

There were no consistent associations of total fish or lean fish consumption with levels of PlGF, sFlt-1, or sFlt-1/PlGF ratio. Neither fatty fish nor shellfish were associated with angiogenic factors. Plasma omega-3 polyunsaturated fatty acids, which are the main type of fatty acids in fish, were inconsistently associated with angiogenic factors in second trimester and cord blood. Yet, higher levels of arachidonic acid, an omega-6 polyunsaturated fatty acid, were associated with lower levels of PlGF and sFlt-1.

DISCUSSION

We found no consistent associations of fish consumption or fatty acids levels with angiogenic factors in a population with low fish consumption. Studies including populations with higher fish consumption are required to fully grasp the potential effects of maternal fish consumption on placental angiogenesis.

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.

A comparison of actual versus stated label amounts of EPA and DHA in commercial omega-3 dietary supplements in the United States

BACKGROUND

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are associated with health benefits throughout life and are obtained primarily through fish and fish oil supplements. Due to the growing popularity of dietary supplements, 47 commercial fish, krill, and algal oil supplements were analyzed for EPA, DHA, and other fatty acids.

RESULTS

For fish- and krill-based supplements, the range of EPA was 81.8 to 454.6 mg g(-1) oil and DHA was 51.6 to 220.4 mg g(-1) oil. For algal oil supplements, EPA ranged from 7.7 to 151.1 mg g(-1) oil and DHA ranged from 237.8 to 423.5 mg g(-1) oil. The percentage of the stated label amount for EPA and DHA ranged from 66 to 184% and 62 to 184%, respectively. Only 10 supplements (21% of those tested) had at least 100% of the stated label amount of EPA, while 12 supplements (25% of those tested) had at least 100% of the stated amount of DHA. Over 70% of the supplements tested did not contain the stated label amount of EPA or DHA.

CONCLUSIONS

These results indicate that the quality of fish oil supplements is not being adequately monitored by manufacturers or government agencies and increased testing is needed to ensure regulatory compliance.

Bronchopulmonary dysplasia: NHLBI Workshop on the Primary Prevention of Chronic Lung Diseases

Bronchopulmonary dysplasia (BPD) is the most common complication of extreme preterm birth. Infants who develop BPD manifest aberrant or arrested pulmonary development and can experience lifelong alterations in cardiopulmonary function. Despite decades of promising research, primary prevention of BPD has proven elusive. This workshop report identifies current barriers to the conduct of primary prevention studies for BPD and causal pathways implicated in BPD pathogenesis. Throughout, we highlight promising areas for research to improve understanding of normal and aberrant lung development, distinguish BPD endotypes, and ascertain biomarkers for more targeted therapeutic approaches to prevention. We conclude with research recommendations and priorities to accelerate discovery and promote lung health in infants born preterm.

Adipose tissue dysregulation and metabolic consequences in childhood and adolescent obesity: potential impact of dietary fat quality

Evidence suggests that at a population level, childhood and adolescent obesity increase the long-term risk of chronic diseases such as type 2 diabetes and CVD. At an individual level, however, the metabolic consequences of obesity in youth vary immensely. Despite comparable BMI, some adolescents develop impaired glucose tolerance while others maintain normal glucose homeostasis. It has been proposed that the variation in the capacity to store lipid in the subcutaneous adipose tissue (SAT) may partially discriminate metabolically healthy from unhealthy obesity. In positive energy balance, a decreased capacity to expand SAT may drive lipid accumulation to visceral adipose tissue, liver and skeletal muscle. This state of lipotoxicity is associated with chronic low-grade inflammation, insulin resistance and dyslipidaemia. The present review examines the differential adipose tissue development and function in children and adolescents who exhibit metabolic dysregulation compared with those who are protected. Additionally, the role of manipulating dietary fat quality to potentially prevent and treat metabolic dysfunction in obesity will be discussed. The findings of the present review highlight the need for further randomised controlled trials to establish the effect of dietary n-3 PUFA on the metabolic phenotype of obese children and adolescents. Furthermore, using a personalised nutrition approach to target interventions to those at risk of, or those with established metabolic dysregulation may optimise the efficacy of modifying dietary fat quality.

Omega-3 polyunsaturated fatty acids enhance cytokine production and oxidative stress in a mouse model of preterm labor

OBJECTIVE

Omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplementation during pregnancy remains controversial. We sought to examine the effects of ω-3 PUFA on inflammation and oxidative stress in vitro and in vivo using a model of preterm labor.

METHODS

In vivo. Female Swiss Webster mice were fed a normal diet or a 5% fish oil (FO) diet for 3 weeks then mated with normal-fed males. On gestational day 15, dams were injected with either saline (n=10 per group) or lipopolysaccharide (LPS, intrauterine) (n=10 per group). Maternal plasma, amniotic fluid, placentas, and uteri were collected 4 h later and assessed for cytokines; maternal plasma and amniotic fluids were analyzed for oxidative stress. In vitro. RAW264.7 mouse macrophage-like cells were treated with either: vehicle, H2O2, docosahexaenoic acid (DHA), or eicosapentaenoic acid (EPA) (0, 0.1-100 μM) and analyzed for oxidative stress.

RESULTS

In vivo. Administration of the 5% FO diet enhanced LPS-induced cytokines in the placenta (P<0.05-0.01) and increased tumor necrosis factor-α in the uterus (P<0.05) and amniotic fluid (P<0.01) when compared to LPS-treated normal-fed animals. Maternal plasma obtained from FO-fed dams showed higher LPS-induced oxidative stress than control-fed animals (P<0.035). However, no differences in oxidative stress were observed in the amniotic fluid. In vitro. Treatment of macrophage-like cells with ω-3 PUFA significantly and dose-dependently increased oxidative stress (P<0.001-0.0001).

CONCLUSIONS

Supplementation with FO for prior to and during pregnancy significantly increased LPS-induced inflammation in the amniotic fluid, uterus, and placenta and significantly increased maternal systemic oxidative stress in vivo. Likewise, DHA and EPA induced oxidative stress in macrophage-like cells in vitro.

Dichotomisation of a continuous outcome and effect on meta-analyses: illustration of the distributional approach using the outcome birthweight

BACKGROUND

Power and precision are greater in meta-analyses than individual study analyses. However, dichotomisation of continuous outcomes in certain studies poses a problem as estimates from primary studies can only be pooled if they have a common outcome. Meta-analyses may include pooled summaries of either or both the continuous and dichotomous forms, and potentially have a different combination of studies for each depending on whether the outcome was dichotomised in the primary studies or not. This dual-outcome issue can lead to loss of power and/or selection bias. In this study we aimed to illustrate how dichotomisation of a continuous outcome in primary studies may result in biased estimates of pooled risk and odds ratios in meta-analysis using secondary analyses of published meta-analyses with the outcome, birthweight, which is commonly analysed both as continuous, and dichotomous (low birthweight: birthweight < 2,500 g).

METHODS

Meta-analyses published in January 2010 - December 2011 were obtained using searches in PubMed, Embase, Web of Science, and Cochrane Database of Systematic Reviews with the outcome birthweight. We used a distributional method to estimate the pooled odds/risk ratio of low birthweight and its standard error as a function of the data reported in the primary studies of the included meta-analyses where accessible.

RESULTS

Seventy-six meta-analyses were identified. Thirty-seven percent (28/76) of the meta-analyses reported only the dichotomous form of the outcome while 26% (20/76) reported only the continuous form. In one meta-analysis (1/76), birthweight was analysed as continuous for one intervention and as binary for another and 36% (27/76) presented both dichotomous and continuous birthweight summaries. In meta-analyses with a continuous outcome, primary studies data were accessible in 39/48 and secondary analyses using the distributional approach provided consistent inferences for both the continuous and distributional estimates in 38/39.

CONCLUSION

The distributional method applied in primary studies allows both a continuous and dichotomous outcome to be estimated providing consistent inferences. The use of this method in primary studies may restrict selective outcome bias in meta-analyses.

Fish intake during pregnancy, fetal growth, and gestational length in 19 European birth cohort studies

BACKGROUND

Fish is a rich source of essential nutrients for fetal development, but in contrast, it is also a well-known route of exposure to environmental pollutants.

OBJECTIVE

We assessed whether fish intake during pregnancy is associated with fetal growth and the length of gestation in a panel of European birth cohort studies.

DESIGN

The study sample of 151,880 mother-child pairs was derived from 19 population-based European birth cohort studies. Individual data from cohorts were pooled and harmonized. Adjusted cohort-specific effect estimates were combined by using a random- and fixed-effects meta-analysis.

RESULTS

Women who ate fish >1 time/wk during pregnancy had lower risk of preterm birth than did women who rarely ate fish (≤ 1 time/wk); the adjusted RR of fish intake >1 but <3 times/wk was 0.87 (95% CI: 0.82, 0.92), and for intake ≥ 3 times/wk, the adjusted RR was 0.89 (95% CI: 0.84, 0.96). Women with a higher intake of fish during pregnancy gave birth to neonates with a higher birth weight by 8.9 g (95% CI: 3.3, 14.6 g) for >1 but <3 times/wk and 15.2 g (95% CI: 8.9, 21.5 g) for ≥ 3 times/wk independent of gestational age. The association was greater in smokers and in overweight or obese women. Findings were consistent across cohorts.

CONCLUSION

This large, international study indicates that moderate fish intake during pregnancy is associated with lower risk of preterm birth and a small but significant increase in birth weight.

n-3 LC-PUFA supplementation: effects on infant and maternal outcomes

BACKGROUND

Long-chain polyunsaturated fatty acids (LC-PUFA), particularly docosahexaenoic acid (DHA) and arachidonic acid, are, respectively, n-3 and n-6 family members and play an important role in fetal and infant growth and development. Pregnancy and lactation impose special nutritional needs for the mother-fetus situation. Since the LC-PUFA required by the fetus is supplied by preferential placental transfer of preformed LC-PUFA rather than their precursor, it has been hypothesized that additional maternal supply of LC-PUFA, especially DHA, during pregnancy may improve maternal and infant outcomes.

AIM

To summarize evidences of the effect of n-3 LC-PUFA intake during pregnancy and lactation on maternal and infant outcomes in order to offer a comprehensive view of this issue that should be useful for clinical practice.

RESULTS

Maternal n-3 LC-PUFA supplementation may reduce risk for early preterm birth >34 weeks and seems very promising for primary allergy prevention during childhood. On the contrary, there are not sufficient data proving that the consumption of oils rich in n-3 LC-PUFA during pregnancy optimizes child's visual and neurodevelopment and reduces the risk for preeclampsia and perinatal depression; the implications of these findings remain to be elucidated.

CONCLUSION

The implications of n-3 LC-PUFA supplementation on fetal development, maternal outcomes and later infant growth is worth being elucidated and is promising in its potential for a positive impact on fetal and maternal outcomes.

Maternal dietary intake of dioxins and polychlorinated biphenyls and birth size in the Norwegian Mother and Child Cohort Study (MoBa)

Maternal diet not only provides essential nutrients to the developing fetus but is also a source of prenatal exposure to environmental contaminants. We investigated the association between dietary intake of dioxins and PCBs during pregnancy and birth size. The study included 50,651 women from the Norwegian Mother and Child Cohort Study (MoBa). Dietary information was collected by FFQs and intake estimates were calculated by combining food consumption and food concentration of dioxins, dioxin-like PCBs and non-dioxin-like PCBs. We used multivariable regression models to estimate the association between dietary intake of dioxins and PCBs and fetal growth. The contribution of fish and seafood intake during pregnancy was 41% for dietary dioxins and dioxin-like PCBs and 49% for dietary non-dioxin-like PCBs. Further stratified analysis by quartiles of seafood intake during pregnancy was conducted. We found an inverse dose-response association between dietary intake of dioxins and PCBs and fetal growth after adjustment for confounders. Newborns of mothers in the upper quartile of dioxin and dioxin-like PCBs intake had 62g lower birth weight (95% CI: -73, -50), 0.26cm shorter birth length (95% CI: -0.31, -0.20) and 0.10cm shorter head circumference (95% CI: -0.14, -0.06) than newborns of mothers in the lowest quartile of intake. Similar negative associations for intake of dioxins and dioxin-like PCBs were found after excluding women with intakes above the tolerable weekly intake (TWI=14pg TEQ/kg bw/week). The negative association of dietary dioxins and PCBs with fetal growth was weaker as seafood intake was increasing. No association was found between dietary dioxin and PCB intake and the risk for small-for-gestational age neonate. In conclusion, dietary intakes of dioxins and PCBs during pregnancy were negatively associated with fetal growth, even at intakes below the TWI.

Evidence-based interventions for improvement of maternal and child nutrition: what can be done and at what cost?

Maternal undernutrition contributes to 800,000 neonatal deaths annually through small for gestational age births; stunting, wasting, and micronutrient deficiencies are estimated to underlie nearly 3·1 million child deaths annually. Progress has been made with many interventions implemented at scale and the evidence for effectiveness of nutrition interventions and delivery strategies has grown since The Lancet Series on Maternal and Child Undernutrition in 2008. We did a comprehensive update of interventions to address undernutrition and micronutrient deficiencies in women and children and used standard methods to assess emerging new evidence for delivery platforms. We modelled the effect on lives saved and cost of these interventions in the 34 countries that have 90% of the world's children with stunted growth. We also examined the effect of various delivery platforms and delivery options using community health workers to engage poor populations and promote behaviour change, access and uptake of interventions. Our analysis suggests the current total of deaths in children younger than 5 years can be reduced by 15% if populations can access ten evidence-based nutrition interventions at 90% coverage. Additionally, access to and uptake of iodised salt can alleviate iodine deficiency and improve health outcomes. Accelerated gains are possible and about a fifth of the existing burden of stunting can be averted using these approaches, if access is improved in this way. The estimated total additional annual cost involved for scaling up access to these ten direct nutrition interventions in the 34 focus countries is Int$9·6 billion per year. Continued investments in nutrition-specific interventions to avert maternal and child undernutrition and micronutrient deficiencies through community engagement and delivery strategies that can reach poor segments of the population at greatest risk can make a great difference. If this improved access is linked to nutrition-sensitive approaches--ie, women's empowerment, agriculture, food systems, education, employment, social protection, and safety nets--they can greatly accelerate progress in countries with the highest burden of maternal and child undernutrition and mortality.

DHA supplementation: current implications in pregnancy and childhood

Dietary supplementation with ω-3 long chain fatty acids including docosahexaenoic acid (DHA) has increased in popularity in recent years and adequate DHA supplementation during pregnancy and early childhood is of clinical importance. Some evidence has been built for the neuro-cognitive benefits of supplementation with long chain polyunsaturated fatty acids (LCPUFA) such as DHA during pregnancy; however, recent data indicate that the anti-inflammatory properties may be of at least equal significance. Adequate DHA availability in the fetus/infant optimizes brain and retinal maturation in part by influencing neurotransmitter pathways. The anti-inflammatory properties of LCPUFA are largely mediated through modulation of signaling either directly through binding to receptors or through changes in lipid raft formation and receptor presentation. Our goal is to review the current findings on DHA supplementation, specifically in pregnancy and infant neurodevelopment, as a pharmacologic agent with both preventative and therapeutic value. Given the overall benefits of DHA, maternal and infant supplementation may improve neurological outcomes especially in vulernable populations. However, optimal composition of the supplement and dosing and treatment strategies still need to be determined to lend support for routine supplementation.