Low fish intake is associated with low blood concentrations of vitamin D, choline and n-3 DHA in pregnant women

Low levels of Vitamin D during pregnancy associated with gestational diabetes mellitus and low birth weight: results from the MAASTHI birth cohort

Introduction

India has a high prevalence of Vitamin D insufficiency among women of childbearing age. In this study, we aimed to evaluate the potential relationship between Vitamin D deficiency and gestational diabetes mellitus (GDM) and low birth weight (LBW) of newborns in the "Maternal antecedents of adiposity and studying the transgenerational role of hyperglycaemia and insulin" (MAASTHI) birth cohort.

Methods

A prospective cohort study involving 230 participants was conducted in public hospitals located in urban Bengaluru, India. Healthy pregnant women who visited these hospitals for antenatal care (ANC) and who were between 14 and 36 weeks of gestational age were recruited after obtaining their informed consent. An oral glucose tolerance test (OGTT) was administered between 24 and 36 weeks of pregnancy and blood samples were preserved at -80°C for Vitamin D analysis. Follow-up at birth included recording the child's birth weight.

Results

We found that 178 (77.4%) of the study participants were vitamin D deficient, 44 (19.1%) were diagnosed with GDM, and 64 (27.8%) gave birth to LBW babies. Women in the lowest quartile of serum Vitamin D levels had three times higher odds of developing GDM than women in the higher quartiles [OR = 3.22 (95% CI: 1.03, 10.07), p = 0.04] after adjusting for age, parity, socioeconomic status, season, and adiposity. For every one-unit increase in Vitamin D levels, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) decreased by nearly 18%. Furthermore, causal mediation analysis showed that a decrease in one unit of Vitamin D is associated with a decrease of 0.015 units of fasting blood sugar (FBS) and 0.019 units of postprandial blood sugar (PPBS) as it flows through the mediator variable insulin resistance. Vitamin D-deficient women were twice at risk of giving birth to LBW babies (OR 2.04, 95% CI 0.99, 4.19, p = 0.05).

Discussions

Low levels of Vitamin D during pregnancy are associated with a greater risk of pregnant women developing GDM and giving birth to LBW babies in urban Bengaluru.

Effects of prenatal exposure and co-exposure to metallic or metalloid elements on early infant neurodevelopmental outcomes in areas with small-scale gold mining activities in Northern Tanzania

BACKGROUND

Artisanal and small-scale gold mining (ASGM) is associated with release of neurotoxic metallic or metalloid chemical elements including lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As).

OBJECTIVE

To examine associations between prenatal exposure and co-exposure to total lead (T-Pb), total mercury (T-Hg), total cadmium (T-Cd) and total arsenic (T-As) and infant neurodevelopment at 6 to 12 months of age in areas with ASGM activities in Tanzania.

METHODS

Women in their second trimester of pregnancy who resided in ASGM areas were enrolled from 2015 to 2017 (n = 883). At 6 to 12 months of age, children were assessed with the Malawi Developmental Assessment Tool (MDAT) (n = 439). We measured T-Pb, T-Hg, and T-Cd in maternal dried blood spots and T-As in maternal urines. Poisson regression was used to examine associations between prenatal concentrations of these elements and neurodevelopmental outcomes.

RESULTS

Prenatal T-Hg concentration was associated with global neurodevelopment status (aPR 1.03, CI:1.01-1.04; p < 0.001) and language impairment (aPR 1.05, CI:1.03-1.07; p < 0.001) on the MDAT. When prenatal T-Hg and T-As values were at or above the human biomonitoring reference values (≥95%) of the German Environmental Survey for Human Biomonitoring, that is 0.80 µg/L and 15 µg/L, respectively, the prevalence ratio of global neurodevelopmental impairment was two times higher (aPR 2.1, CI:1.0-4.3; p = 0.034). There was a 40% increase in the prevalence ratio of global neurodevelopmental impairment (aPR 1.4, CI:0.90-2.10, p = 0.027), when prenatal T-Hg was at or above the reference value of 0.80 µg/L and T-Pb was at or above the reference value of 35 µg/L. When prenatal T-Hg was at or above the reference value of 0.80 µg/L and T-As was at or above the reference value of 15 µg/L, the prevalence ratio of global neurodevelopmental impairment was two times higher (aPR 2.1, CI:1.0-4.3; p < 0.034).

DISCUSSION

Infants born to women in areas with ASGM activities are at significant risk for neurodevelopmental impairment and this is associated with exposure to higher concentrations of Hg prenatally. Co-exposure to high concentrations of Hg and Pb, or Hg and As appeared to have negative potentiated effects on infants' neurodevelopment.

Longitudinal changes during pregnancy in gut microbiota and methylmercury biomarkers, and reversal of microbe-exposure correlations

OBJECTIVE

Gut microorganisms contribute to the metabolism of environmental toxicants, including methylmercury (MeHg). Our main objective was to investigate whether associations between biomarkers for prenatal MeHg exposure and maternal gut microbiota differed between early and late gestation.

METHODS

Maternal blood and stool samples were collected during early (8.3-17 weeks, n=28) and late (27-36 weeks, n=24) gestation. Total mercury and MeHg concentrations were quantified in biomarkers, and inorganic mercury was estimated by subtraction. The diversity and structure of the gut microbiota were investigated using 16S rRNA gene profiling (n = 52). Biomarkers were dichotomized, and diversity patterns were compared between high/low mercury concentrations. Spearman's correlation was used to assess bivariate associations between MeHg biomarkers (stool, blood, and meconium), and 23 gut microbial taxa (genus or family level, >1% average relative abundance).

RESULTS

Within-person and between-person diversity patterns in gut microbiota differed between early/late gestation. The overall composition of the microbiome differed between high/low MeHg concentrations (in blood and stool) during early gestation, but not late gestation. Ten (of 23) taxa were significantly correlated with MeHg biomarkers (increasing or decreasing); however, associations differed, depending on whether the sample was collected during early or late gestation. A total of 43% of associations (69/161) reversed the direction of correlation between early/late gestation.

CONCLUSIONS

The time point at which a maternal fecal sample is collected may yield different associations between gut microorganisms and MeHg biomarkers, which may be due in part to remodeling of maternal microbiota during pregnancy. Our results suggest the effectiveness of dietary interventions to reduce prenatal MeHg exposure may differ between early and late gestation.

Nutritional value of the Tunisian mussel Mytilus galloprovincialis with a special emphasis on lipid quality

This study reports, for the first time, data on nutritional quality parameters in Tunisian mussels, Mytilus galloprovincialis, with an especial emphasis on lipid compounds. Mussel condition index (CI), proximate composition and fatty acid profiles were investigated for a one year period in order to identify the best harvesting period. Analysis revealed that polyunsaturated fatty acids (PUFA) were the dominant fatty acids with a prevalence of n-3 over n-6 forms. Pearson's correlation indicated a strong relationship between CI and PUFA compound and Principal Components Analysis suggested that, from winter to summer, the product maintained a condition sufficiently good for marketing. The best CI and lipid quantity/quality occurred during summer and this may be used as criteria for product labelling. The study also included a thorough literature review that allowed data comparison on mussels from various Mediterranean sites and allowed the mussels from the Bizerte lagoon (North of Tunisia) to be differentiated.

Maternal prenatal blood mercury is not adversely associated with offspring IQ at 8 years provided the mother eats fish: A British prebirth cohort study

Background

Conflicting evidence concerning possible harm from mercury (Hg) in regard to offspring cognition if the woman eats fish has prompted this study to examine evidence from a British pre-birth cohort to investigate the relationship between the two.

Methods

Pregnant women (median prenatal blood mercury 1.86 μg/L) resident in the study area with delivery between April 1991 and December 1992 were followed up and verbal, performance and total intelligence quotient (IQ) of 2062 offspring were measured at age 8. Analysis treated IQ as (a) continuous and (b) the lowest 25% of the distribution. Multiple and logistic regression analyses took account of social and demographic variables. Stratification considered children of fish eaters separately.

Results

Before adjustment, mean full-scale IQ increased with increasing Hg (change with 1SD of Hg = +2.02; 95%CI +1.40,+2.64 IQ points; P < 0.0001); after adjustment effect size was reduced although still positive (+0.61;95%CI -0.06,+1.29 IQ points; P = 0.073). The adjusted positive relationship was stronger when fish-eating mothers were considered separately (+0.84:95%CI +0.13,+1.56 IQ points; P = 0.021) in comparison with the outcomes for non-fish eaters, where the adjusted relationship was negative (-2.22;95%CI -5.00,+0.56 IQ points; P = 0.117). The binary outcome showed a similar pattern with the adjusted OR for non-fish-eaters 1.79 (95%CI 1.10,2.93; P = 0.019) per SD of Hg, significantly different from that for fish consumers (0.94;95%CI:0.82,1.08)(P_interaction<0.05). There were no differences between the sexes in the associations, nor did the level of the mother’s blood selenium change the effect sizes.

Conclusion

The relationship between intrauterine exposure to mercury and offspring IQ appears to be benign provided the mother consumes fish.

Determinants of maternal vitamin D concentrations in Slovenia : A prospective observational study

OBJECTIVE

To analyze the vitamin D status of pregnant women in Slovenia and the factors influencing it.

METHODS

The study was performed in Maribor University Medical Centre (location 46°N). Maternal serum 25-hydroxy-vitamin D (25(OH)D) in 4 groups of 100 pregnant women in 4 different seasons of the year was measured at the time of delivery. Data on life style, eating habits, sunbathing and intake of vitamin D supplements during pregnancy were obtained using a questionnaire. Information on maternal outcome was acquired from medical records. Duration of sunlight and average temperature in the month preceding delivery were calculated from meteorological data.

RESULTS

The average maternal 25(OH)D concentration ranged from 28.5 ± 17.1 nmol/l in March to 54.8 ± 24.1 nmol/l in June (p < 0.001). Severe vitamin D deficiency, i.e. <25 nmol/l 25(OH)D was present in 23.6% of women overall. In multiple regression analysis supplements containing vitamin D (β = 0.225, p < 0.001) and duration of intentional exposure to sunlight (β = 0.192, p = 0.026) were associated with maternal 25(OH)D status. Significantly lower vitamin D levels were observed in women who had a cesarean section (t = 2.053, p = 0.041) and those with premature delivery (t = 2.296, p = 0.022). Vitamin D levels were not associated with the occurrence of gestational diabetes, gestational hypertension or infections during pregnancy.

CONCLUSION

A high prevalence of vitamin D deficiency was detected at the end of pregnancy, especially in the months following autumn and winter and in women who did not take supplements containing vitamin D.

The effect of fish oil supplementation on serum phospholipid fatty acids profile during pregnancy: A double blind randomized controlled trial

Omega-3 fatty acids (FAs) are essential unsaturated long-chain FAs necessary for proper health and growth. The objective of the authors in this study was to evaluate the effect of fish oil supplementation in pregnancy on maternal serum FA profiles. Participants (n = 150 pregnant women aged 18-35 years in Tabriz, Iran) were randomly assigned to receive either 1,000 mg fish oil supplements daily containing 120 mg docosahexanoic acid (DHA) and 180 mg eicosapentaenoic acid (EPA), or placebo from week 21 of pregnancy to delivery. The primary outcome measures were mean serum DHA and EPA proportion of total FAs at weeks 35-37 of pregnancy. Analyses were based on intention-to-treat. No significant differences were observed between the groups in consumption of fish and serum FAs levels at baseline. Fish oil supplementation significantly increased the mean DHA proportion of total FAs in the intervention compared to the placebo group at weeks 35-37 [adjusted Mean Difference (aMD) = 0.15; 95% CI 0.08-0.23]. The mean EPA proportion of total FAs also increased in the intervention group, but the difference between the groups was not significant (aMD = 0.04; 95% CI -0.01 to 0.08). The dietary recommendation for consumption of 1,000 mg/day fish oil supplements during pregnancy seems beneficial for better serum FA composition.

Associations between prenatal mercury exposure and early child development in the ALSPAC study

INTRODUCTION

There is evidence that high levels of mercury exposure to the pregnant woman can result in damage to the brain of the developing fetus. However there is uncertainty as to whether lower levels of the metal have adverse effects on the development of the infant and whether components of fish consumption and/or the selenium status of the woman is protective.

METHODS

In this study we analysed data from the Avon Longitudinal Study of Parents and Children (ALSPAC) (n=2875-3264) to determine whether levels of total blood mercury of pregnant women collected in the first half of pregnancy are associated with the development of the offspring at ages 6, 18, 30 and 42 months. The developmental measures used maternal self-reported scales for individual types of development (fine and gross motor, social and communication skills) and total scores. Multiple and logistic regression analyses treated the outcomes both as continuous and as suboptimal (the lowest 15th centile). The statistical analyses first examined the association of prenatal mercury exposure with these developmental endpoints and then adjusted each for a number of social and maternal lifestyle factors; finally this model was adjusted for the blood selenium level.

RESULTS

Total maternal prenatal blood mercury and selenium ranged from 0.17 to 12.76 and 17.0 to 324μg/L respectively. We found no evidence to suggest that prenatal levels of maternal blood mercury were associated with adverse development of the child, even when the mother had consumed no fish during pregnancy. In general, the higher the mercury level the more advanced the development of the child within the range of exposure studied. For example, the fully adjusted effect sizes for total development at 6 and 42 months were +0.51 [95%CI +0.05, +1.00] and +0.43 [95%CI +0.08, +0.78] points per SD of mercury. For the risk of suboptimal development the ORs at these ages were 0.90 [95%CI 0.80, 1.02] and 0.88 [95%CI 0.77, 1.02]. In regard to the associations between blood mercury and child development there were no differences between the mothers who ate fish and those who did not, thus implying that the benefits were not solely due to the beneficial nutrients in fish.

CONCLUSIONS

We found no evidence of adverse associations between maternal prenatal blood mercury and child development between 6 and 42 months of age. The significant associations that were present were all in the beneficial direction.

Prenatal choline and the development of schizophrenia

Background

The primary prevention of illness at the population level, the ultimate aim of medicine, seems out of reach for schizophrenia. Schizophrenia has a strong genetic component, and its pathogenesis begins long before the emergence of psychosis, as early as fetal brain development. Cholinergic neurotransmission at nicotinic receptors is a pathophysiological mechanism related to one aspect of this genetic risk. Choline activates these nicotinic receptors during fetal brain development. Dietary supplementation of maternal choline thus emerges as a possible intervention in pregnancy to alter the earliest developmental course of the illness.

Aim

Review available literature on the relationship of choline supplementation or choline levels during pregnancy and fetal brain development.

Methods

A Medline search was used to identify studies assessing effects of choline in human fetal development. Studies of other prenatal risk factors for schizophrenia and the role of cholinergic neurotransmission in its pathophysiology were also identified.

Results

Dietary requirements for choline are high during pregnancy because of its several uses, including membrane biosynthesis, one-carbon metabolism, and cholinergic neurotransmission. Its ability to act directly at high concentrations as a nicotinic agonist is critical for normal brain circuit development. Dietary supplementation in the second and third trimesters with phosphatidyl-choline supports these functions and is associated generally with better fetal outcome. Improvement in inhibitory neuronal functions whose deficit is associated with schizophrenia and attention deficit disorder has been observed.

Conclusion

Prenatal dietary supplementation with phosphatidyl-choline and promotion of diets rich in choline-containing foods (meats, soybeans, and eggs) are possible interventions to promote fetal brain development and thereby decrease the risk of subsequent mental illnesses. The low risk and short (sixmonth) duration of the intervention makes it especially conducive to population-wide adoption. Similar findings with folate for the prevention of cleft palate led to recommendations for prenatal pharmacological supplementation and dietary improvement. However, definitive proof of the efficacy of prenatal choline supplementation will not be available for decades (because of the 20-year lag until the onset of schizophrenia), so public health officials need to decide whether or not promoting choline supplementation is justified based on the limited information available.

A randomized longitudinal dietary intervention study during pregnancy: effects on fish intake, phospholipids, and body composition

Background

Fish and meat intake may affect gestational weight gain, body composition and serum fatty acids. We aimed to determine whether a longitudinal dietary intervention during pregnancy could increase fish intake, affect serum phospholipid fatty acids, gestational weight gain and body composition changes during pregnancy in women of normal weight participating in the Pregnancy Obesity Nutrition and Child Health study. A second aim was to study possible effects in early pregnancy of fish intake and meat intake, respectively, on serum phospholipid fatty acids, gestational weight gain, and body composition changes during pregnancy.

Methods

In this prospective, randomized controlled study, women were allocated to a control group or to a dietary counseling group that focused on increasing fish intake. Fat mass and fat-free mass were measured by air-displacement plethysmography. Reported intake of fish and meat was collected from a baseline population and from a subgroup of women who participated in each trimester of their pregnancies. Serum levels of phospholipid arachidonic acid (s-ARA), eicosapentaenoic acid (s-EPA), and docosahexaenoic acid (s-DHA) were measured during each trimester.

Results

Weekly fish intake increased only in the intervention group (n = 18) from the first to the second trimester (median difference 113 g, p = 0.03) and from the first to the third trimester (median difference 75 g, p = 0.01). In the first trimester, fish intake correlated with s-EPA (r = 0.36, p = 0.002, n = 69) and s-DHA (r = 0.34, p = 0.005, n = 69), and meat intake correlated with s-ARA (r = 0.28, p = 0.02, n = 69). Fat-free mass gain correlated with reported meat intake in the first trimester (r = 0.39, p = 0.01, n = 45).

Conclusions

Dietary counseling throughout pregnancy could help women increase their fish intake. Intake of meat in early pregnancy may increase the gain in fat-free mass during pregnancy.

Typical prenatal vitamin D supplement intake does not prevent decrease of plasma 25-hydroxyvitamin D at birth

OBJECTIVE

The objective of this longitudinal study was to determine what typical vitamin D predictors influence the change in vitamin D status from mid-pregnancy to birth.

METHODS

Plasma 25-hydroxyvitamin D [25(OH)D] was determined at mid-pregnancy (8-20 weeks gestation) and following birth (n = 193). Usual predictors of vitamin D status [body mass index (BMI), race, season] in addition to prenatal supplemental vitamin D intake and docosahexaenoic acid (DHA) status at delivery were assessed for their interaction on the change on plasma 25(OH)D concentration between the two time points.

RESULTS

Forty-nine percent of women had inadequate vitamin D status [categorized as deficient (<30 nmol/L) or insufficient (30-49.9 nmol/L) by IOM guidelines] at mid-pregnancy and 82% were deficient or insufficient at birth. Plasma 25(OH)D concentration dropped 61% from mid-pregnancy to birth. Season of birth (F = 7.86, P = 0.006) and mid-pregnancy plasma 25(OH)D concentration (F = 6.17, P = 0.014) were significant variables in the change of vitamin D status while BMI, race, DHA status, and typical vitamin D intake (334 IU/day) from prenatal supplements did not have an effect. Women who delivered in summer and fall had a 1.5-fold greater plasma 25(OH)D concentration than women who delivered in winter in spring (41.1 ± 23.1 and 40.7 ± 20.5 nmol/L summer and fall, respectively, versus 27.7 ± 17.9 and 29.3 ± 21.4 nmol/L in winter and spring, respectively).

CONCLUSIONS

Typical supplemental vitamin D intake during pregnancy did not prevent precipitous drops in maternal plasma 25(OH)D concentration. Clinicians and dietitians should be aware of the risk of inadequate vitamin D status in pregnant women in the United States relative to their initial vitamin D status and the season of birth.

Meeting the fetal requirement for polyunsaturated fatty acids in pregnancy

PURPOSE OF REVIEW

The aim of this review is to summarize recent evidence on the importance of individual long chain polyunsaturated fatty acid (LCPUFA) to the developing fetus and the maternal dietary requirement for these.

RECENT FINDINGS

Large-scale randomized controlled trials and innovative genetic and stable isotope studies are providing new insights in this field.

SUMMARY

Large randomized controlled trials of LCPUFA supplementation in pregnancy suggest that higher n-3 LCPUFA intake reduces the risk of preterm birth and increases the length of gestation, with secondary effects on birth weight. There is little evidence of an effect on postnatal visual function and cognition, but interpretation is complicated by maternal metabolic adaptations and adipose tissue status in the newborn. The links between polymorphisms in the FADS genes and tissue fatty acid composition suggest that LCPUFA synthesis influences overall availability. Stable isotope studies have also demonstrated the capacity for LCPUFA synthesis in pregnancy, the fact that n-6 synthesis is greater than n-3, metabolic channeling of individual fatty acids to different fates, and selective placental transfer. Studies linking FADS genotype to cognition imply that n-3 LCPUFA synthesis could have an effect on infant cognition, but more large-scale genetic studies are needed.

Early second trimester maternal plasma choline and betaine are related to measures of early cognitive development in term infants

BACKGROUND

The importance of maternal dietary choline for fetal neural development and later cognitive function has been well-documented in experimental studies. Although choline is an essential dietary nutrient for humans, evidence that low maternal choline in pregnancy impacts neurodevelopment in human infants is lacking. We determined potential associations between maternal plasma free choline and its metabolites betaine and dimethylglycine in pregnancy and infant neurodevelopment at 18 months of age.

METHODOLOGY

This was a prospective study of healthy pregnant women and their full-term, single birth infants. Maternal blood was collected at 16 and 36 weeks of gestation and infant neurodevelopment was assessed at 18 months of age for 154 mother-infant pairs. Maternal plasma choline, betaine, dimethylglycine, methionine, homocysteine, cysteine, total B12, holotranscobalamin and folate were quantified. Infant neurodevelopment was evaluated using the Bayley Scales of Infant Development-III. Multivariate regression, adjusting for covariates that impact development, was used to determine the associations between maternal plasma choline, betaine and dimethylglycine and infant neurodevelopment.

RESULTS

The maternal plasma free choline at 16 and 36 weeks gestation was median (interquartile range) 6.70 (5.78-8.03) and 9.40 (8.10-11.3) µmol/L, respectively. Estimated choline intakes were (mean ± SD) 383 ± 98.6 mg/day, and lower than the recommended 450 mg/day. Betaine intakes were 142 ± 70.2 mg/day. Significant positive associations were found between infant cognitive test scores and maternal plasma free choline (B=6.054, SE=2.283, p=0.009) and betaine (B=7.350, SE=1.933, p=0.0002) at 16 weeks of gestation. Maternal folate, total B12, or holotranscobalamin were not related to infant development.

CONCLUSION

We show that choline status in the first half of pregnancy is associated with cognitive development among healthy term gestation infants. More work is needed on the potential limitation of choline or betaine in the diets of pregnant women.