Do Thyroid Diseases during Pregnancy and Lactation Affect the Nutritional Composition of Human Milk?

A study of the effect of hypothyroidism during pregnancy on human milk quality based on rheological properties

Hypothyroidism has been found to have an effect on the nutritional composition of human milk during pregnancy. This study aims to explore the combined influence of rheological properties, macronutrient content, particle size, and the zeta potential of milk fat globules, as well as the composition of milk fat globule membrane (MFGM) proteins on the quality of human milk in gestational hypothyroidism. The study revealed that human milk from the group with hypothyroidism during pregnancy (AHM) was less viscoelastic and stable when compared with normal pregnancy group human milk (NHM). Furthermore, the particle size and macronutrient content of NHM were found to be larger than that of AHM. In contrast, the zeta potential of AHM was greater than that of NHM. The sodium dodecyl sulfate-PAGE results disclosed that the composition of MFGM proteins in these 2 groups were generally the same, but the content of AHM was lower than that of NHM. In conclusion, this study confirms that hypothyroidism during pregnancy can have a significant effect on the quality of human milk.

Measurement of fecal T3 metabolite levels in sheep: Analytical and biological validation of the method

Introduction

Biological sample collection from wild and farms animals is often associated with difficulties related to the handling and restraint procedures, and most of the time it could induce stress, altering the welfare and physiological homeostasis. The analysis of fecal T3 metabolites (FTMs) allows to test samples collected in a non-invasive manner, providing several information about the animal's physiological conditions and the effects related to environmental and nutritional variations. This procedure has found wide application in wild species, but less in domestic ones.

Methods

The aim of this work was to validate the use of an immuno-enzymatic competitive ELISA kit, designed for T3 quantification in human blood serum samples, for the assessment of FTMs in the sheep. For the analytical validation, precision, recovery and parallelism were evaluated; for biological validation the variations of FTMs in relation to age, sex and the physiological status of the animal were determined.

Results

After a verification of the precision (RSD % < 15%), mean recovery (75%) and parallelism (CV% < 10%), the kit was used to measure FTMs in cyclic, pregnant, and early lactating ewes as well as in rams and ewe lambs. The results showed that FTMs concentrations in pregnant ewes were significantly lower (p < 0.05) than in cyclic and early lactation ones. Furthermore, there were no significant differences in FTMs levels between ewes and rams, while in lambs FTMs levels were higher than in adults (p < 0.001).

Conclusion

In conclusion the present study demonstrates that FTMs can be reliably and accurately determined in sheep feces, using an ELISA kit formulated for human serum T3 assay. The application of this method in the livestock sector could allow to improve our knowledge about the response of animals to different physiological and environmental conditions, and thus assess their welfare.

Uncontrolled Thyroid during Pregnancy Alters the Circulative and Exerted Metabolome

Normal levels of thyroid hormones (THs) are essential for a normal pregnancy outcome, fetal growth and the normal function of the central nervous system. Hypothyroidism, a common endocrine disorder during pregnancy, is a significant metabolic factor leading to cognitive impairments. It is essential to investigate whether patients with thyroid dysfunction may present an altered circulative and excreted metabolic profile, even after receiving treatment with thyroxine supplements. NMR metabolomics was employed to analyze 90 serum and corresponding colostrum samples. Parallel analyses of the two biological specimens provided a snapshot of the maternal metabolism through the excretive and circulating characteristics of mothers. The metabolomics data were analyzed by performing multivariate statistical, biomarker and pathway analyses. Our results highlight the impact of hypothyroidism on metabolites’ composition during pregnancy and lactation. Thyroid disorder causing metabolite fluctuations may lead to impaired lipid and glucose metabolic pathways as well as aberrant prenatal neurodevelopment, thus posing a background for the occurrence of metabolic syndrome or neurogenerative diseases later in life. This risk applies to not only untreated but also hypothyroid women under replacement therapy since our findings in both biofluids framed a different metabolic phenotype for the latter group, thus emphasizing the need to monitor women adequately after treatment initiation.