Maternal selenium deficiency during gestation is positively associated with the risks for LBW and SGA newborns in a Chinese population

Associations between maternal and infant selenium status and child growth in a birth cohort from Dhaka, Bangladesh

Deficiency of essential trace element, Se, has been implicated in adverse birth outcomes and in child linear growth because of its important role in redox biology and associated antioxidant effects. We used data from a randomised controlled trial conducted among a cohort of pregnant and lactating women in Dhaka, Bangladesh to examine associations between Se biomarkers in whole blood (WBSe), serum and selenoprotein P (SEPP1) in maternal delivery and venous cord (VC) blood. Associations between Se biomarkers, birth weight and infant growth outcomes (age-adjusted length, weight, head circumference and weight-for-length z-scores) at birth, 1 and 2 years of age were examined using regression analyses. WB and serum Se were negatively associated with birth weight (adjusted β, 95 % CI, WBSe delivery: −26·6 (–44·3, −8·9); WBSe VC: −19·6 (–33·0, −6·1)); however, delivery SEPP1 levels (adjusted β: −37·5 (–73·0, −2·0)) and VC blood (adjusted β: 82·3 (30·0, 134·7)) showed inconsistent and opposite associations with birth weight. Positive associations for SEPP1 VC suggest preferential transfer from mother to fetus. We found small associations between infant growth and WBSe VC (length-for-age z-score β, 95 % CI, at birth: −0·05 (–0·1, −0·01)); 12 months (β: −0·05 (–0·08, −0·007)). Weight-for-age z-score also showed weak negative associations with delivery WBSe (at birth: −0·07 (–0·1, −0·02); 12 -months: −0·05 (–0·1, −0·005)) and in WBSe VC (at birth: −0·05 (–0·08, −0·02); 12 months: −0·05 (–0·09, −0·004)). Given the fine balance between essential nutritional and toxic properties of Se, it is possible that WB and serum Se may negatively impact growth outcomes, both in utero and postpartum.

Global, regional and national prevalence of copper, selenium and zinc deficiencies in women of childbearing age: protocol for systematic review and meta-analysis

INTRODUCTION

Micronutrient deficiencies are common in low-income and middle-income countries and are usually related to inadequate food intake, poor diet quality and low bioavailability. Copper, selenium and zinc are essential minerals in several enzymatic reactions and their deficiencies are associated with worse prognosis in pregnancy, compromising maternal health as well as her offspring. Thus, the objective of the present systematic review will be to describe the prevalence of copper, selenium and zinc deficiencies in women of childbearing age.

METHODS AND ANALYSIS

The search will be performed by independent reviewers. The bases used will be PubMed/MEDLINE, Science direct, Lilacs, Adolec, Scopus, EMBASE, CINAHL, Web of Science, CENTRAL, IMSEAR, PAHOS, WPRIM, IMEMR, AIM for grey literature OpenGrey and OVID. National data will be searched in BDTD. A first search will be performed and a second search will be performed just before submission. Risk of bias assessment will be performed using the Joanna Briggs group prevalence study checklist. Combinable studies will be performed meta-analysis. Heterogeneity will be tested using Cochran's Q test and quantified by the inconsistency test (I²). In the presence of high heterogeneity, meta-analysis will be performed using the random effects model with Stata metaprop. Summary prevalence will be generated for each outcome, presented in Forest plot figures.

ETHICS AND DISSEMINATION

This systematic review will be solely based on published and retrievable literature, no ethics approval will be obtained. Our dissemination strategy will involve the presentation in scientific meetings, as well as the publication of article(s), posters and presentations in congresses.

PROSPERO REGISTRATION NUMBER

CRD42020165352.

Transcriptomic analysis reveals the effects of maternal selenium deficiency on placental transport, hormone synthesis, and immune response in mice

Selenium deficiency has been considered to increase the risk of gestational complications. Our previous work showed that maternal selenium deficiency suppressed proliferation, induced autophagy dysfunction and apoptosis in the placenta of mice. However, other effects of maternal selenium deficiency on the placenta and the underlying mechanisms remain unclear. In the present study, dietary selenium deficiency in dams significantly suppressed glutathione peroxidase (GSH-Px) activity, total antioxidant capacity (T-AOC), and increased malondialdehyde (MDA) content in the placentae, confirming the oxidative stress in the placenta. By transcriptome sequencing analysis, the DEGs were involved in many biological processes, including ion transport, lipid metabolic process, immune response, transmembrane transport, and others. According to the KEGG analysis, the DEGs were primarily enriched in metabolic pathways, PI3K-Akt signaling pathway, and others. Among these, the steroid hormone biosynthesis pathway enriched the most DEGs. Hsd3b1, an ER enzyme involved in progesterone synthesis, was validated downregulated. Consistently, the progesterone content in the serum of the selenium-deficient group was decreased. Ion transporters and transmembrane transporters, such as Heph, Trf, Slc39a8, Slc23a1, Atp7b, and Kcnc1, were reduced in the selenium-deficient placentae. Immune response-related genes, including Ccl3, Ccl8, Cxcl10, and Cxcl14, were increased in the selenium-deficient placentae, along with an increase in macrophage number. These results suggested that maternal selenium deficiency may impair progesterone biosynthesis, reduce nutrient transporters expression, and promote immune response by increasing the oxidative stress of the placentae. This present study provides a novel insight into the possible cause of placenta disorder during pregnancy.

Zinc homeostasis in immunity and its association with preterm births

Preterm birth is among the most common adverse pregnancy outcomes and is the leading cause of neonatal mortality and morbidity. While trace elements are essential for humans, their specific roles in the prenatal period remain unexplored. Zinc, a ubiquitous element plays a pivotal role in protein synthesis, cell division, nucleic acid metabolism, apoptosis, ageing, reproduction, immunological as well as antioxidant defense mechanism. Although zinc quantities are very small in body tissue, it is involved in every conceivable biochemical pathway which is critical for the performance of various functions necessary to sustain life. Owing to the multifactorial role of zinc, it is not possible to attribute a certain zinc dependent mechanism in pre-term births. Although the effect of zinc deficiency on immunity, its impact on maternal function and health as well as its role in the developing foetus is well documented, much less attention has been given to the understanding of micronutrient zinc homeostasis in immunity and its association with preterm births. Despite extensive research, the pathway by which zinc regulates pregnancy outcomes as well as the function of immune cells in controlling the delivery status (term/ preterm) is still obscure. The present review aims to focus on the understanding of relationship of micronutrient zinc homeostasis in immunity and its association with preterm births.

Maternal selenium deficiency suppresses proliferation, induces autophagy dysfunction and apoptosis in the placenta of mice

Selenium deficiency is thought to be associated with the occurrence of gestational complications. However, the underlying mechanism of selenium deficiency impairs placental function remains unclear. In this study, female mice were separately supplemented with a Se-deficient (0.02 mg/kg Se) or control diet (0.2 mg/kg Se) for 12 weeks before mating and throughout gestation. Maternal liver and placentas were collected at embryonic day 15.5 and analyzed for Se content. Oxidative stress status, proliferation capability, autophagy, and apoptosis of the placenta were determined. We found that maternal selenium deficiency decreased placental Se concentration and some antioxidant selenoproteins expressions. The concentrations of catalase and glutathione in selenium-deficient placentas were reduced, along with an increase in hydrogen peroxide (H2O2) content. Selenium deficiency inhibited the expression of proliferating cell nuclear antigen. Autophagosomes, autophagolysosomes, and upregulation of autophagy-related protein microtubule-associated protein 1 light chain 3 alpha II (LC3B), Beclin1, PTEN-induced putative kinase 1 (PINK1), and Parkin were found in the selenium-deficient trophoblasts. Autophagic substrate p62/sequestosome 1 was surprisingly increased, indicating autophagy flux dysfunction. Selenium deficiency increased expressions of B cell leukemia/lymphoma 2 associated X protein (Bax), cleaved caspase-9/-3, and decreased the B cell leukemia/lymphoma 2 (Bcl2) level. Moreover, typical apoptotic ultrastructure and apoptosis-positive cells were observed in the selenium-deficient placenta. Our results suggested that maternal selenium deficiency impaired placental proliferation, induced autophagy dysfunction and apoptosis via increasing oxidative stress, and the Akt/mechanistic target of rapamycin (mTOR) pathway involved in this process. This study revealed a novel mechanism by which maternal selenium deficiency caused impairment of the placenta.

Novel metabolic marker Afamin: A predictive factor for Large-for-Gestational-Age (LGA) fetus estimation in pregnancies with gestational diabetes mellitus?

OBJECTIVE

Gestational diabetes mellitus (GDM) affects both maternal and fetal/infant outcomes during and after pregnancy. The reason for the high incidence of large-for-gestational-age (LGA) infants in GDM patients despite close monitorization of glucose levels with early detection of the disease remains unclear to date. Our study aims to investigate the levels of the third-trimester novel marker afamin in GDM versus non-GDM pregnancies in terms of glycemic control status and their utility in the prediction of LGA fetuses.

MATERIAL AND METHODS

This prospective case-control study analysis involved 49 pregnant women with GDM diagnosed using the 75-g oral glucose tolerance test (75-g OGTT) and 40 randomly selected women with a similar body mass index (BMI) and gestational age (GA). Blood samples were collected in the third trimester of pregnancy. The afamin level was determined using a human afamin ELISA kit according to the manufacturer's procedure.

RESULTS

There was no significant difference found in BMI or GA of patients. Third-trimester afamin levels were 93.91 mg/L and 83.87 mg/L in the GDM and non-GDM groups, respectively (p=0.625). Afamin values of patients were not correlated with age, BMI, GA, HgA1c, 75-g OGTT fasting and 75-g OGTT 1-hour, or 75-g OGTT 2-hour values (p>0.05). GDM patients with LGA fetuses had significantly higher afamin values than patients with appropriate-for-gestational-age (AGA) fetuses (120.8 mg/L versus 91.26 mg/L, respectively). Between GDM patients with either LGA or AGA fetuses, there was no statistically significant difference found for age, BMI, GAs, insulin dose, 75-g OGTT results, or HgA1c values.

CONCLUSION

Our findings conclude that novel marker afamin levels could predict the risk of LGA infants independently of glycemic control status and provide insight into the pathogenesis of LGA fetuses, thus helping to reduce the risk of associated complications.