High-Throughput Analysis of Water-Soluble Forms of Choline and Related Metabolites in Human Milk by UPLC-MS/MS and Its Application

Relationship between one-carbon metabolism and fetal growth in twins: A cohort study

We investigated the associations of one-carbon metabolism (OCM)-related metabolites, including choline, betaine, dimethylglycine (DMG), and methionine with fetal growth of twins. This hospital-based cohort study included dichorionic twin gestations. Blood samples were collected at a median of 14.7 weeks of gestation. Blood plasma metabolite levels were measured using high-performance liquid chromatography-triple quadrupole mass spectrometry. Generalized estimating equations and mixed effects models were used to explore associations between plasma metabolite levels and fetal growth. In total, 115 women with dichorionic diamniotic pregnancies were included. The maternal plasma DMG level was negatively correlated with fetal birth weight (β = -43.5, 95% confidence interval [CI] = -74.1 to -12.8, p < .05) and head circumference (β = -0.23, 95% CI = -0.39 to -0.07, p < .05). Other metabolites were not significantly associated with birth weight, body length, head circumference (HC), or chest circumference. Analysis of the relationships between plasma metabolite levels and fetal biological parameters on ultrasound revealed that the maternal choline level was negatively correlated with fetal abdominal circumference (AC) (β = -0.12, 95% CI = 0.24 to -0.004, p < .05); the maternal DMG level was negatively correlated with fetal AC (β = -0.17, 95% CI = 0.28-0.07, p < .05), femur length (β = 0.02, 95% CI = 0.04-0.003, p < .05), and estimated fetal weight (β = 26.4, 95% CI = -41.6 to -11.2, p < .05), but not with HC. The maternal methionine level was negatively correlated with HC (β = -0.08, 95% CI = -0.14 to -0.02, p < .05). The plasma level of the OCM-related metabolite DMG during the second trimester was negatively correlated with fetal intrauterine growth and birth weight. However, further studies with larger samples are needed.

B-Vitamins and Choline in Human Milk Are Not Impacted by a Preconception Lipid-Based Nutrient Supplement, but Differ Among Three Low-to-Middle Income Settings-Findings From the Women First Trial

Introduction: Optimal human milk (HM) B-vitamin concentrations remain undefined, especially in areas where undernutrition is prevalent. The impact of supplementation pre-conception through pregnancy on HM B-vitamin composition remains unknown.

Methods: Human milk (HM) was collected at 2-weeks postpartum from 200 women in Guatemala, India, and Pakistan (the Women First Trial). The women were randomized to start a lipid-based nutrient supplement before conception, at end of the first trimester, or not at all; intervention continued until delivery. HM concentrations of eight B-vitamins and choline were assessed via ultra-performance liquid chromatography-tandem mass spectrometry. Maternal diet was assessed in early pregnancy, and infant growth followed through 6 months post-delivery.

Results: Despite supplement exposure averaging 15.7 (pre-conception arm) and 6.0 months (prenatal arm), HM B-vitamins did not differ between arms, but site differences were evident. Guatemala had higher HM concentrations of vitamin B3 than Pakistan and India. Pakistan had higher HM concentrations of thiamin and vitamin B6 than India and Guatemala. Cohort average HM vitamin B2 (162 ± 79 μg/L) and B6 (31.8 ± 24.6 μg/L) fell below values defined as deficient in 81.5 and 85.5% of samples, potentially reflecting sampling procedures and timing. Maternal dietary intakes of only vitamin B6 and choline were associated with the corresponding concentrations in HM (p < 0.005). No HM B-vitamin concentrations were associated with infant growth.

Conclusion: Prenatal supplementation for at least 6 months had no impact on HM B-vitamin concentrations at 2-weeks postpartum. Results suggest that the adequacy of HM composition was generally maintained, with potential exceptions of vitamin B2 and B6.

Factors associated with longitudinal changes in B-vitamin and choline concentrations of human milk

BACKGROUND

Little is known regarding the associations between maternal factors and B-vitamin and choline concentrations in early milk and the trajectories of these vitamins during lactation.

OBJECTIVES

In this hypothesis-generating study, we modeled the association between maternal and offspring factors and longitudinal changes in milk B-vitamin and choline concentrations throughout lactation.

METHODS

A hundred women were studied in a prospective birth cohort and milk samples from 52 women were collected at 2-8 d, 76 women at 28-50 d, and 42 women at 88-119 d postpartum. Maternal dietary intake during pregnancy and lactation was assessed by an FFQ. Linear mixed-effects models with interaction terms were used to evaluate changes in milk B-vitamin and choline concentrations over time based on maternal factors and the early postpartum concentrations of these micronutrients.

RESULTS

The women with higher early postpartum milk concentrations of niacin (βinteraction = -0.02; SE = 0.00; P < 0.001), pantothenic acid (βinteraction = -0.10; SE = 2.56; P < 0.001), vitamin B-12 (βinteraction= -0.10; SE = 0.03; P < 0.001), and choline (βinteraction= -0.90; SE = 0.18; P < 0.001) exhibited a decrease in their concentrations throughout lactation. The participants with overweight and obesity prepregnancy experienced an increase in milk vitamin B-12 concentrations over time (βinteraction = 0.04; SE = 0.02; P = 0.06). In contrast, a decrease in vitamin B-12 concentration was observed among women with vitamin B-12 intake below the RDA during pregnancy (βinteraction= -0.08; SE = 0.05; P = 0.07). The women with niacin intake below the RDA during lactation experienced an increase in milk concentrations over time (βinteraction = 0.01; SE = 0.01; P = 0.03). A gestational age at birth >40 wk was associated with an increase in milk choline concentration throughout lactation (βinteraction = 0.54; SE = 0.16; P< 0.01).

CONCLUSIONS

Changes in B-vitamin and choline concentrations in human milk over time may be associated with the early concentrations of these micronutrients in milk, maternal prepregnancy BMI, dietary intake, and gestational age at delivery.

The Mothers, Infants, and Lactation Quality (MILQ) Study: A Multi-Center Collaboration

Little valid information is available on human milk nutrient concentrations, especially for micronutrients (MNs), and there are no valid reference values (RVs) across lactation. In this multi-center collaborative study, RVs will be established for human milk nutrients across the first 8.5 mo postpartum. Well-nourished, unsupplemented women in Bangladesh, Brazil, Denmark, and The Gambia (n = 250/site) were recruited during the third trimester of pregnancy. Milk, blood, saliva, urine, and stool samples from mothers and their infants are collected identically at 3 visits (1-3.49, 3.5-5.99, 6.0-8.49 mo postpartum). Milk analyses include macronutrients, selected vitamins, trace elements and minerals, iodine, metabolomics, amino acids, human milk oligosaccharides, and bioactive peptides. We measure milk volume; maternal and infant diets, anthropometry, and morbidity; infant development, maternal genome, and the infant and maternal microbiome. RVs will be constructed based on methods for the WHO Child Growth Standards and the Intergrowth-21st Project. This trial was registered at clinical trials.gov as NCT03254329.