Prevalence and maternal determinants of early and late introduction of complementary foods: results from the Growing Up in New Zealand cohort study.

A nationally generalisable cohort (n 5770) was used to determine the prevalence of non-timely (early/late) introduction of complementary food and core food groups and associations with maternal sociodemographic and health behaviours in New Zealand (NZ). Variables describing maternal characteristics and infant food introduction were sourced, respectively, from interviews completed antenatally and during late infancy. The NZ Infant Feeding Guidelines were used to define early (≤ 4 months) and late (≥ 7 months) introduction. Associations were examined using multivariable multinomial regression, presented as adjusted relative risk ratios and 95 % confidence intervals (RRR; 95% CI). Complementary food introduction was early for 40·2 % and late for 3·2 %. The prevalence of early food group introduction were fruit/vegetables (23·8 %), breads/cereals (36·3 %), iron-rich foods (34·1 %) and of late were meat/meat alternatives (45·9 %), dairy products (46·2 %) and fruits/vegetables (9·9 %). Compared with infants with timely food introduction, risk of early food introduction was increased for infants: breastfed < 6months (2·52; 2·19-2·90), whose mothers were < 30 years old (1·69; 1·46-1·94), had a diploma/trade certificate v. tertiary education (1·39; 1·1-1·70), of Maori v. European ethnicity (1·40; 1·12-1·75) or smoked during pregnancy (1·88; 1·44-2·46). Risk of late food introduction decreased for infants breastfed < 6 months (0·47; 0.27-0·80) and increased for infants whose mothers had secondary v. tertiary education (2·04; 1·16-3·60) were of Asian v. European ethnicity (2·22; 1·35, 3·63) or did not attend childbirth preparation classes (2·23; 1·24-4·01). Non-timely food introduction, specifically early food introduction, is prevalent in NZ. Interventions to improve food introduction timeliness should be ethnic-specific and support longer breast-feeding.

Changes in HMO Concentrations throughout Lactation: Influencing Factors, Health Effects and Opportunities.

Human milk oligosaccharides (HMOs) are important functional biomolecules in human breast milk. Understanding the factors influencing differences in HMO composition and changes in their concentration over lactation can help to design feeding strategies that are well-adapted to infant's needs. This review summarises the total and individual concentration of HMOs from data published from 1999 to 2019. Studies show that the HMO concentrations are highest in colostrum (average 9-22 g/L), followed by slightly lower concentrations in transitional milk (average 8-19 g/L), with a gradual decline in mature milk as lactation progresses, from 6-15 g/L in breast milk collected within one month of birth, to 4-6 g/L after 6 months. Significant differences in HMO composition have been described between countries. Different HMOs were shown to be predominant over the course of lactation, e.g., 3-fucosyllactose increased over lactation, whereas 2'-fucosyllactose decreased. Recent clinical studies on infant formula supplemented with 2'-fucosyllactose in combination with other oligosaccharides showed its limited beneficial effect on infant health.

Maternal influences on the glucocorticoid concentrations of human milk: The STEPS study.

BACKGROUND & AIMS: Human milk (HM) contains a wide array of non-nutritive bioactive elements, including glucocorticoid hormones (glucocorticoid; cortisol and cortisone). The relationship between milk-borne glucocorticoids, measures of maternal health and patterns of breast-feeding is not yet established. This study was conducted to determine the influence of maternal and infant related biological and socio-demographic factors on the levels of glucocorticoids hormones in HM. METHODS: Samples were obtained from lactating mothers (n = 656) participating in the Finnish cohort the STEPS study (Steps to the Healthy Development and Well-being of Children) when the infants were 11.29 (±2.6) weeks of age. Glucocorticoids (both cortisol and cortisone) concentrations were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Maternal demographics, biological and social factors were obtained using hospital records and self-reported diaries and questionnaires. RESULTS: The majority of women reported that they were exclusively breastfeeding at the time of sample donation (51.2%). For all collected samples, cortisone (9.55 ± 3.44 ng/ml) was the predominant hormone and cortisol (7.39 ± 5.97 ng/ml) was present in all samples. Strong and positive correlation was found between cortisol and cortisone (r = 0.60, p=<0.0001). Cortisone was statistically different between overweight, normal and underweight women (p = 0.01) for cortisol no difference was seen (p = 0.96). Whilst, preterm birth (born before 37 week gestation) was positively associated with both cortisol (p = 0.04) and cortisone (p = 0.01). There was also a significant but weaker negative relationship between mothers educational status and cortisol (p = 0.05) and no effect was seen for cortisone (p = 0.82). Interestingly, no significant differences was found in glucocorticoid concentrations between exclusive and partial breastfeeding women. CONCLUSION: HM contains glucocorticoids hormones. The concentrations are influenced by the varying maternal factors including maternal weight, preterm birth and maternal educational status, suggesting the possible role of maternal biological and social influences on milk hormonal composition. Interestingly, there was no influence of feeding patterns on HM glucocorticoids. Further analysis is required to fully explore the relationship with measures of maternal stress, including mother's glucocorticoid status.

Vitamin D status of exclusively breastfed infants aged 2-3 months.

BACKGROUND: New Zealand in 2008 adopted WHO policy which recommends that all infants are exclusively breast fed until 6 months of age. The benefits of this policy for the infant are undisputed; however, this policy has the potential to adversely impact on infant vitamin D status. A number of countries now recommend that all breastfed infants receive daily vitamin D supplementation of 400 IU to prevent rickets. New Zealand has no policy on the vitamin D supplementation of 'low-risk' breastfed infants. There are no data on the vitamin D status of exclusively breastfed infants in the first few months of life in New Zealand. AIM: To describe serum 25-hydroxy-vitamin D (25(OH)D) concentrations in exclusively breastfed infants aged 2-3 months. DESIGN/METHODS: Healthy term exclusively breastfed infants who were receiving no vitamin D supplements were enrolled over a 15-month period. A capillary blood sample was obtained from each infant. Serum 25(OH)D was measured using isotope-dilution liquid chromatography-tandem mass spectrometry. RESULTS: 94 infants were enrolled (mean age 10 weeks). Median 25(OH)D concentration was 53 nmol/l (IQR 14-100 nmol/l). 23 (24%) infants had serum 25(OH)D concentration <27.5 nmol/l. Infants enrolled during winter had a median (IQR) 25(OH)D serum concentration of 21 nmol/l (14,31). Infants enrolled during summer had a median (IQR) 25(OH)D concentration of 75 nmol/l (55 100) (winter vs summer, p<0.0001). CONCLUSIONS: Vitamin D deficiency is prevalent in exclusively breastfed infants in New Zealand. Vitamin D supplementation should be considered as part of New Zealand's child health policy.