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

Fatty acids and pregnancy-induced hypertension: a Mendelian randomization study

BACKGROUND

It is well known that pregnancy-induced hypertension (PIH) contributes significantly to the mortality rates of both mothers and babies during pregnancy. The relationship between fatty acids (FAs) and PIH remains debatable, with the causality between the two yet to be definitively established.

METHODS

Two-sample univariable and multivariable Mendelian Randomization (MR) analyses were executed, based on pooled data from Genome-Wide Association Studies (GWAS), to investigate any causal impact of FAs on PIH. A suite of methods was employed to assess causality, including inverse variance weighting (IVW), weighted median, MR Egger, simple mode, and weighted mode. Subsequently, the data underwent a sensitivity analysis (using Leave-One-Out analysis), a heterogeneity test (with MR-PRESSO and Cochran's Q test), as well as a multiple validity test (using MR-Egger regression). In multivariable analyses, fatty acids were first grouped to observe the effect of individual FAs on PIH. Subsequently, factors such as diabetes, high blood pressure, and body mass index (BMI) were incorporated into a multivariable examination of the impact of each FA on PIH. During this process, the IVW, weighted median, MR-Lasso, and MR-Egger methods were employed.

RESULTS

A systematic investigation was conducted into the causal impact of each FA on PIH. The findings indicated that Polyunsaturated Fatty Acids (PUFA), Omega3, the ratio of Omega6 to Omega3, and Docosahexaenoic Acid (DHA) have a causal relationship with PIH. Increases in PUFA, Omega3, and DHA could potentially reduce the risk of PIH, while an increase in the Omega6/Omega3 ratio could heighten the risk. The impacts of other FAs (including Total Fatty Acids, Monounsaturated Fatty Acids (MUFA), Saturated Fatty Acids (SFA), and Omega 6) on PIH were not substantiated by the MR analysis. In the univariate leave-one-out analysis, rs174564 was identified in PUFA, Omega3, and DHA as having a significant role. The tests with MR-Egger and MR-PRESSO found that the results were not influenced by pleiotropy and heterogeneity. After adjusting for BMI, Diabetes Mellitus, and pre-existing hypertension in the multivariable analysis, the results mirrored those obtained univariable.

CONCLUSION

The research implies that elevated levels of circulating PUFA, DHA, and Omega3 may serve as a protective mechanism against PIH, while higher Omega6/Omega3 ratios could potentially increase the risk of PIH. These findings may inform clinical strategies for PIH prevention.

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.

Insight on Polyunsaturated Fatty Acids in Endometrial Receptivity

Endometrial receptivity plays a crucial role in fertilization as well as pregnancy outcome in patients faced with fertility challenges. The optimization of endometrial receptivity may help with normal implantation of the embryo, and endometrial receptivity may be affected by numerous factors. Recently, the role of lipids in pregnancy has been increasingly recognized. Fatty acids and their metabolites may be involved in all stages of pregnancy and play a role in supporting cell proliferation and development, participating in cell signaling and regulating cell function. Polyunsaturated fatty acids, in particular, are essential fatty acids for the human body that can affect the receptivity of the endometrium through in a variety of methods, such as producing prostaglandins, estrogen and progesterone, among others. Additionally, polyunsaturated fatty acids are also involved in immunity and the regulation of endometrial decidualization. Fatty acids are essential for fetal placental growth and development. The interrelationship of polyunsaturated fatty acids with these substances and how they may affect endometrial receptivity will be reviewed in this article.

Effects of Fish Oil Supplementation on Pregnancy Outcomes in Pregnant Women Referred to Kosar Hospital

The hypothesis of a protective effect of fish oil supplementation in preventing some consequences of pregnancy such as gestational hypertension is put forward which has attracted increasing attention. The aim of the present study was to evaluate the effect of fish oil supplementation on outcomes of pregnancy. This study was a clinical trial performed on 339 women with singleton pregnancy aged 18-35 and gestational age of 20 weeks who visited prenatal clinic at Kosar Hospital in Qazvin during 2015-2016. Patients were randomly divided into two groups marked as intervention group which received soft gelatin capsules (each containing 1000 mg fish oil including 120 mg DHA and 180 mg EPA) on a daily basis from the 20^th week to the end of pregnancy, and the women in the control group with no fish oil intake. The outcomes of pregnancy including preeclampsia, eclampsia, preterm labor, gestational diabetes, weight, height, head circumference at birth and the gestational age at delivery were evaluated in both groups. Data were analyzed using statistical tests including Mann-Whitney U test and t-test. There was significant difference in gestational age between the two study groups (P < 0.05). There was no significant difference in the percentage of preterm birth, preeclampsia, eclampsia, IUGR, and GDM between the two groups (P > 0.05). The results of this study showed that consumption of fish oil supplements from 20^th week of gestation by 18-35 year-old pregnant women increased pregnancy age but failed to decrease the percentage of preterm birth, preeclampsia, eclampsia, IUGR, and GDM.

Co-expression of fat1 and fat2 in transgenic pigs promotes synthesis of polyunsaturated fatty acids

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are essential for the development and health of mammals, such as humans and livestock. n-3 PUFAs must be supplied by diet due to the absence of a key gene, namely, delta-15 desaturase (fat1), which is responsible for synthesizing n-3 PUFAs from a major type of n-6 PUFAs, linoleic acid (LA). To increase the dietary intake of n-3 PUFAs for humans, fat1-expressing transgenic (TG) livestock have been produced to provide n-3 PUFA-rich meats for humans. However, these TG livestock synthesized n-3 PUFAs from diet-derived, instead of endogenously produced, n-6 PUFAs because they still lack the delta-12 desaturase (fat2) gene for catalyzing conversion of internal oleic acid (OA) to LA. To fill the gap in the de novo n-3 PUFA biosynthesis pathway and to increase n-3 PUFA content in livestock, TG pigs co-expressing fat1-fat2 were generated in the present work. The OA content decreased in fat1-fat2 TG pigs, suggesting that OA was converted to LA by fat2 transgene-encoded delta-12 desaturase. The n-3 PUFA level was elevated, and the n-6/n-3 PUFA ratio dropped in fat1-fat2 TG pigs, revealing that fat1 transgene promoted the synthesis of n-3 PUFAs from n-6 analogs. The expression levels of fatty acid elongase-5 (ELOVL5) and fatty acid elongase-2 (ELOVL2), which are two key enzyme genes for PUFA synthesis, as well as their transcription factor peroxisome proliferator-activated receptor α, increased in fat1-fat2 TG pigs. Thus, the fat1 transgene enhanced n-3 PUFA synthesis by upregulating the expression of enzyme genes involved in the PUFA synthesis pathways. Overall, this study provided a new strategy to produce n-3 PUFA-rich meat for human consumption. The generated fat1-fat2 TG pigs can also serve as a large animal model for studying the roles of n-3 PUFAs in human development and health.

Role of omega-3 polyunsaturated fatty acids in gestational diabetes, maternal and fetal insights: current use and future directions

ω-3-Polyunsaturated fatty acids (ω-3 PUFAs) are widely used during pregnancy and gestational diabetes mellitus (GDM). ω-3 PUFAs are beneficial in the regulation of maternal and fetal metabolic function, inflammation, immunity, macrosomia (MAC), oxidative stress, preeclampsia, intrauterine growth, preterm birth, offspring metabolic function, and neurodevelopment. Dietary counseling is vital for improving therapeutic outcomes in patients with GDM. In maternal circulation, ω-3 PUFAs are transported via transporters, synthesis enzymes, and intracellular proteins, which activate nuclear receptors and play central roles in the cellular metabolic processes of placental trophoblasts. In patients with GDM, this process is compromised due to abnormal functioning of the placenta, which disrupts the normal mother to fetus transport. This results in reduced fetal levels of ω-3 PUFAs, which contributes negatively to fetal growth, metabolic function, and development. Dietary counseling and nutritional assessment remain challenging in the prevention and alleviation of GDM. Therefore, personalized approaches, including measurement of the ω-3 index, pharmacogenetic implementation strategies, and appropriate supplementation with ω-3 PUFAs are used to achieve sufficient distribution in the maternal and fetal fluids during the entire pregnancy period. Developing new dosing guidelines and personalized approaches, determining the mechanisms of ω-3 PUFAs in the placenta, and examining the pharmacodynamic and pharmacokinetics interactions involving ω-3 PUFAs will lead to better management and increase the quality of life of patients with GDM and their offspring. Moreover, different strategies for supplementing with ω-3 PUFAs, improving their placental transport, and pharmacological exploration of the maternal-fetal interactions will help to further elucidate the role of ω-3 PUFAs in women with GDM. In this review, we summarize the current information on the potential therapeutic benefits and clinical applicability of ω-3 PUFAs in patients with GDM and their offspring, highlighting recent progress and future perspectives in this field. Studies investigating the mechanisms of ω-3 PUFA transport to targeted tissues have spurred an interest in personalized treatment strategies for patients with GDM and their offspring. To implement such therapies, we need to clarify the index/ratio of ω-3 PUFAs in maternal and fetal fluids, delineate the ω-3 PUFA transport pathways, and establish the guidelines for FA profiling prepregnancy and during pregnancy-associated weight gain. Such therapies also need to take into account the gender of the fetus, and whether the patient is obese.

FABP4 in Gestational Diabetes-Association between Mothers and Offspring

Fetuses exposed to gestational diabetes mellitus (GDM) have a higher risk of abnormal glucose homeostasis in later life. The molecular mechanisms of this phenomenon are still not fully understood. Fatty acid binding protein 4 (FABP4) appears to be one of the most probable candidates involved in the pathophysiology of GDM. The main aim of the study was to investigate whether umbilical cord serum FABP4 concentrations are altered in term neonates born to GDM mothers. Two groups of subjects were selected—28 healthy controls and 26 patients with GDM. FABP4, leptin, and ghrelin concentrations in the umbilical cord serum, maternal serum, and maternal urine were determined via an enzyme-linked immunosorbent assay. The umbilical cord serum FABP4 levels were higher in the GDM offspring and were directly associated with the maternal serum FABP4 and leptin levels, as well as the prepregnancy body mass index (BMI) and the BMI at and after delivery; however, they correlated negatively with birth weight and lipid parameters. In the multiple linear regression models, the umbilical cord serum FABP4 concentrations depended positively on the maternal serum FABP4 and negatively on the umbilical cord serum ghrelin levels and the high-density lipoprotein cholesterol. There are many maternal variables that can affect the level of FABP4 in the umbilical cord serum, thus, their evaluation requires further investigation.

Increased α-Linolenic Acid Intake during Pregnancy is Associated with Higher Offspring Birth Weight

BACKGROUND

The amount and type of fat in the maternal diet during pregnancy are important contributors to fetal growth. The importance of plant-based omega-3 fatty acid (α-linolenic acid, ALA) intake in fetal growth has not been previously examined.

OBJECTIVE

We sought to determine the association of maternal ALA intake during pregnancy with birth weight and body composition of the offspring.

METHODS

Mothers and their newborn infants (n = 224) were recruited from the Royal Prince Alfred Hospital, Australia. Maternal diet during pregnancy was assessed using a validated food frequency questionnaire. Plasma fatty acid composition was analyzed in a subset of mothers (n = 41). Newborn body composition was assessed using air-displacement plethysmography. All analyses were adjusted for gestational age, sex, physical activity, and total energy intake.

RESULTS

Dietary fatty acid intakes were positively associated with plasma phospholipid fatty acids for total omega-3 fatty acids (β = 0.452, P = 0.003), ALA (β = 0.339, P = 0.03), linoleic acid (β = 0.353, P = 0.03), eicosapentaenoic acid (β = 0.407, P = 0.009), and docosahexaenoic acid (β = 0.388, P = 0.01). Higher maternal intake of ALA (% total fat) was associated with higher offspring birth weight [189.7-g increase per 1% higher ALA (95% CI: 14, 365 g); P = .04], although individually neither newborn fat mass nor fat-free mass was significant. Birth weight increased across tertiles of maternal ALA intake (P ANOVA = 0.05), with birth weight being 221 g (95% CI: 12, 429 g) higher in those with the highest maternal ALA intake compared with those with the lowest intake (P = 0.04). Mothers of infants born small for gestational age (n = 32) had a lower ALA intake than those born appropriate for gestational age (n = 162) or large for gestational age [(n = 21); P = 0.05].

CONCLUSIONS

In otherwise healthy women giving birth at a major tertiary hospital in Australia, intake of ALA during pregnancy is associated with higher offspring birth weight. This may have implications for dietary strategies aimed at optimizing fetal growth via modification of maternal diet.