Examining the Effect of Fish Oil Supplementation in Chinese Pregnant Women on Gestation Duration and Risk of Preterm Delivery

Effect of Fish-Based Diet on Malnourished Children: A Systematic Review

Background

Malnutrition in children is mainly caused by the lack of protein and fat intake which harms their ability to grow and survive. Accurate data on the benefits of fish-based foods on the nutritional status of children is limited. The present systematic review aimed to provide an overview of published articles on the nutritional value of fish-based foods for children.

Methods

A systematic review was performed during 2000-2021 by searching Science Direct, Cochrane Library, PubMed, ProQuest, and Wiley Online Library databases. The full text of selected articles in English was screened based on the inclusion and exclusion criteria. Included articles were all experimental studies (randomized control trial, quasi-randomized trial) or mixed methods studies involving malnourished children. The study was reported under the preferred reporting items for systematic reviews and meta-analyses guidelines. The risk of bias was assessed using the Cochrane tool.

Results

A total of 330,859 articles were screened, out of which eight articles were included in the systematic review. Interventions included fish-based foods and beverages such as wafer bars, Jemawut-tuna cookies, Amizate in chocolate drink, dried fish powder, flaxseed oil supplemented with fish oil capsules, and porridge fortified with fish powder. Primary or secondary outcomes were the determination of zinc level, height growth, erythrocyte n-3 polyunsaturated fatty acid content, safety and acceptability, intestinal integrity, and cognitive development. The results showed that dried fish powder produced the most significant effect on body weight.

Conclusion

The consumption of dried fish powder had positive effects on the recovery of malnourished children.

Omega-3 fatty acid supply in pregnancy for risk reduction of preterm and early preterm birth

This clinical practice guideline on the supply of the omega-3 docosahexaenoic acid and eicosapentaenoic acid in pregnant women for risk reduction of preterm birth and early preterm birth was developed with support from several medical-scientific organizations, and is based on a review of the available strong evidence from randomized clinical trials and a formal consensus process. We concluded the following. Women of childbearing age should obtain a supply of at least 250 mg/d of docosahexaenoic+eicosapentaenoic acid from diet or supplements, and in pregnancy an additional intake of ≥100 to 200 mg/d of docosahexaenoic acid. Pregnant women with a low docosahexaenoic acid intake and/or low docosahexaenoic acid blood levels have an increased risk of preterm birth and early preterm birth. Thus, they should receive a supply of approximately 600 to 1000 mg/d of docosahexaenoic+eicosapentaenoic acid, or docosahexaenoic acid alone, given that this dosage showed significant reduction of preterm birth and early preterm birth in randomized controlled trials. This additional supply should preferably begin in the second trimester of pregnancy (not later than approximately 20 weeks' gestation) and continue until approximately 37 weeks' gestation or until childbirth if before 37 weeks' gestation. Identification of women with inadequate omega-3 supply is achievable by a set of standardized questions on intake. Docosahexaenoic acid measurement from blood is another option to identify women with low status, but further standardization of laboratory methods and appropriate cutoff values is needed. Information on how to achieve an appropriate intake of docosahexaenoic acid or docosahexaenoic+eicosapentaenoic acid for women of childbearing age and pregnant women should be provided to women and their partners.

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

OBJECTIVES

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

DESIGN

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

SETTING

6 tertiary care centres in four states in Australia.

PARTICIPANTS

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

INTERVENTIONS

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

OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION NUMBER

ACTRN12613001142729.

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

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

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

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

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Choline and docosahexaenoic acid during the first 1000 days and children's health and development in low- and middle-income countries

Choline and DHA are nutrients that, when provided during the first 1000 days from conception to age 2 years, may have beneficial effects on child neurodevelopment as well as related health factors, including birth outcomes and child growth, morbidity, and inflammation. Because these nutrients are found mainly in animal-source foods, they may be lacking in the diets of pregnant and lactating women and young children in low- and middle-income countries, potentially putting children at risk for suboptimal development and health. Prior reviews of these nutrients have mainly focused on studies from high-income countries. Here, a narrative review is presented of studies describing the pre- and postnatal roles of choline, docosahexaenoic acid, and a combination of the 2 nutrients on child neurodevelopment, birth outcomes, growth, morbidity, and inflammation in low- and middle-income countries. More studies are needed to understand the specific, long-term effects of perinatal choline and docosahexaenoic acid intake in various contexts.

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

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

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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.

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

OBJECTIVE

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

DESIGN

Exploratory analysis of a randomised controlled trial.

SETTING

Six Australian hospitals.

POPULATION

Women with a singleton pregnancy enrolled in the ORIP trial.

METHODS

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

MAIN OUTCOME MEASURE

Early preterm birth (<34 weeks' gestation).

RESULTS

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

CONCLUSIONS

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

TWEETABLE ABSTRACT

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