Nutritional adequacy and the role of supplements in the diets of Indigenous Australian women during pregnancy

Gestational diabetes mellitus is associated with distinct folate-related metabolites in early and mid-pregnancy: A prospective cohort study

AIMS

This study aimed to evaluate the association between gestational diabetes mellitus (GDM) and circulating folate metabolites, folic acid (FA) intake, and the methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genotype.

MATERIALS AND METHODS

A prospective pregnancy cohort study was conducted in Beijing, China, from 2022 to 2023. Circulating folate metabolites, including red blood cell (RBC) 5-methyltetrahydrofolate (5-MTHF), 5, 10-methylene-tetrahydrofolate (5,10-CH2-THF), 5- formyltetrahydrofolate (5-CHO-THF), and unmetabolised folic acid (UMFA), and plasma homocysteine (HCY), 5-MTHF, and methylmalonic acid (MMA), were determined at 6-17 weeks and 20-26 weeks of gestation. FA intake and the MTHFR and MTRR genotype were also examined. GDM was diagnosed between 24 and 28 weeks of pregnancy by a 75-g oral glucose tolerance test (OGTT). The association between the folate status and GDM was ascertained using multivariate generalised linear models, logistic regression models, and restricted cubic spline regression, adjusting for potential confounders.

RESULTS

The study included 2032 pregnant women, of whom 392 (19.29%) developed GDM. UMFA above the 75th percentile (≥P75) [adjusted OR (aOR) (95% confidence interval [CI]) = 1.36 (1.01-1.84)], UMFA ≥ P90 [aOR (95% CI) = 1.82 (1.23-2.69)], and HCY ≥ P75 [aOR (95% CI) = 1.40 (1.04-1.88)] in early pregnancy, and RBC 5-MTHF [aOR (95% CI) = 1.48 (1.10-2.00)], RBC 5,10-CH2-THF [aOR (95% CI) = 1.55 (1.15-2.10)], and plasma 5-MTHF [aOR (95% CI) = 1.36 (1.00-1.86)] in mid-pregnancy ≥ P75 are associated with GDM. Higher UMFA levels in early pregnancy show positive associations with the 1-h and 2-h glucose levels during the OGTT, and higher HCY levels are associated with increased fasting glucose levels during the OGTT. In comparison, RBC 5- MTHF and 5,10-CH2-THF, and plasma 5- MTHF in mid-pregnancy are positively associated with the 1-h glucose level (p < 0.05). The MTHFR and MTRR genotype and FA intake are not associated with GDM.

CONCLUSIONS

Elevated levels of UMFA and HCY during early pregnancy, along with elevated RBC 5-MTHF and 5,10-CH2-THF and plasma 5-MTHF during mid-pregnancy, are associated with GDM. These findings indicate distinct connections between different folate metabolites and the occurrence of GDM.

Maternal diet quality and nutrient intakes across preconception and pregnancy are not consistent with Australian guidelines: Results from the pilot BABY1000 study

BACKGROUND AND OBJECTIVE

Maternal nutrition has profound and lasting effects on growth and health from infancy into adulthood. The aim of this manuscript was to assess diet quality and nutrient adequacy in preconception and pregnancy in BABY1000 pilot study participants (n = 171).

STUDY DESIGN AND METHODS

The Australian Eating Survey (AES) Food Frequency Questionnaire was administered to women based in Sydney, Australia, at preconception or 12 weeks' gestation (n = 158), and again at 36 weeks' gestation (n = 99). Primary outcomes were diet quality and nutrient intake. Diet quality was evaluated using the AES diet quality subscale, the Australian Recommended Food Score (ARFS). Nutrient intakes were compared to Australian Nutrient Reference Values. Diet quality and nutrient intakes were not consistent with Australian recommendations. Over 83% of women exceeded the suggested target limits for percentage energy from saturated fat. Median ARFS was 37 at baseline, and 38 in late pregnancy (maximum score 73). Inadequate micronutrient intakes from food were common; no participants met the Estimated Average Requirement for iron, 76%-84% for iodine, 70%-78% for calcium and 44%-50% for folate. Maternal diet quality and nutrient intakes in the current sample are inconsistent with pregnancy recommendations and therefore may not be supporting optimal perinatal or long-term offspring health. Stronger messaging around the importance of prenatal nutrition, prevalence of dietary inadequacy, and availability of reliable support and information specific to nutrition in pregnancy is crucial in supporting women to improve their nutrition both before and during pregnancy.

Omega-3 Fatty Acids during Pregnancy in Indigenous Australian Women of the Gomeroi Gaaynggal Cohort

Higher dietary intakes of Omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) have been linked to lower rates of preterm birth and preeclampsia. The aim of this analysis was to describe dietary intake and fractions of red blood cell (RBC) membrane LC-PUFAs during pregnancy in a cohort of Indigenous Australian women. Maternal dietary intake was assessed using two validated dietary assessment tools and quantified using the AUSNUT (Australian Food and Nutrient) 2011-2013 database. Analysis from a 3-month food frequency questionnaire indicated that 83% of this cohort met national n-3 LC-PUFA recommendations, with 59% meeting alpha-linolenic acid (ALA) recommendations. No nutritional supplements used by the women contained n-3 LC-PUFAs. Over 90% of women had no detectable level of ALA in their RBC membranes, and the median Omega-3 Index was 5.5%. This analysis appears to illustrate a decline in concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) across gestation in women who had preterm birth. However, there was no visible trend in LC-PUFA fractions in women who experienced hypertension during pregnancy. Further research is needed to better understand the link between dietary intake of n-3 LC-PUFA-rich foods and the role of fatty acids in preterm birth and preeclampsia.

Women Taking a Folic Acid Supplement in Countries with Mandatory Food Fortification Programs May Be Exceeding the Upper Tolerable Limit of Folic Acid: A Systematic Review

Background: In preconception and pregnancy, women are encouraged to take folic acid-based supplements over and above food intake. The upper tolerable limit of folic acid is 1000 mcg per day; however, this level was determined to avoid masking a vitamin B12 deficiency and not based on folic acid bioavailability and metabolism. This review’s aim is to assess the total all-source intake of folate in women of childbearing age and in pregnancy in high-income countries with folate food fortification programs. Methods: A systematic search was conducted in five databases to find studies published since 1998 that reported folate and folic acid intake in countries with a mandatory fortification policy. Results: Women of childbearing age do not receive sufficient folate intake from food sources alone even when consuming fortified food products; however, almost all women taking a folic acid-based supplement exceed the upper tolerable limit of folic acid intake. Conclusions: Folic acid supplement recommendations and the upper tolerable limit of 1000 mcg set by policy makers warrant careful review in light of potential adverse effects of exceeding the upper tolerable limit on folic acid absorption and metabolism, and subsequent impacts on women’s health during their childbearing years.

A better start to life: Risk factors for, and prevention of, preterm birth in Australian First Nations women - A narrative review

The unacceptable discrepancies in health outcomes between First Nations and non-Indigenous Australians begin at birth. Preterm birth (birth before 37 completed weeks of gestation) is a major contributor to adverse short- and long-term health outcomes and mortality. Australian First Nations infants are more commonly born too early. No tangible reductions in preterm births have been made in First Nations communities. Factors contributing to high preterm birth rates in Australian First Nations infants are reviewed and interventions to reduce preterm birth in Australian First Nations women are discussed. More must be done to ensure Australian First Nations infants get a better start to life. This can only be achieved with ongoing and improved research in partnership with Australian First Nations peoples.

Maternal Diet Influences Fetal Growth but Not Fetal Kidney Volume in an Australian Indigenous Pregnancy Cohort

Suboptimal nutrition during pregnancy is recognised as a significant modifiable determinant in the development of chronic disease in offspring in later life. The current study aimed: (i) to assess the dietary intakes of pregnant Indigenous Australian women against national recommendations and (ii) to investigate the associations between maternal nutrition during pregnancy and the growth of the offspring, including kidney development in late gestation in the Gomeroi gaaynggal cohort (n = 103). Maternal dietary intake in the third trimester was assessed using the Australian Eating Survey Food Frequency Questionnaire. Estimated fetal weight (EFW) and kidney size were obtained by ultrasound. Birth weight was retrieved from hospital birth records. Of the five key nutrients for optimal reproductive health (folate, iron, calcium, zinc and fibre), the nutrients with the highest percentage of pregnant women achieving the nutrient reference values (NRVs) were zinc (75.7%) and folate (57.3%), whereas iron was the lowest. Only four people achieved all NRVs (folate, iron, calcium, zinc and fibre) important in pregnancy. Sodium and saturated fat intake exceeded recommended levels and diet quality was low, with a median score of 28 out of 73 points. After adjusting for smoking and pre-pregnancy body mass index, only maternal intake of retinol equivalents and the proportion of energy from nutrient-dense or energy-dense, nutrient-poor (EDNP) foods were associated with fetal growth. EFW decreased by 0.13 g and birth weight decreased by 0.24 g for every µg increase in maternal dietary retinol intake. Interestingly, EFW, but not actual birth weight, was positively associated with percentage energy from nutrient dense foods and negatively associated with percentage energy from EDNP foods. Dietary supplement usage was associated with increased birthweight, most significantly iron and folate supplementation. Current dietary intakes of pregnant Australian women from this cohort do not align with national guidelines. Furthermore, current findings show that maternal retinol intake and diet composition during pregnancy can influence fetal growth, but not fetal kidney growth in late gestation. Strategies that aim to support and optimise nutrient intakes of Indigenous pregnant women are urgently needed. Future studies with long-term follow-up of the children in the current cohort to assess renal damage and blood pressure are imperative.