Effects of selenium levels on placental oxidative stress and inflammation during pregnancy: a prospective cohort study

Abstract

Background

Studies on the impact of Se levels in different pregnancy periods on placental function are limited.

Aim

This cohort study sought to investigate the levels of the trace element Se and to assess their effects on placental oxidative stress (OS) and mRNA expression of inflammatory genes during pregnancy.

Methods

The study population consisted of 2519 pregnant women from the Ma’anshan birth cohort. Se levels were measured in the first and second trimesters of pregnancy and in cord blood using inductively coupled plasma-mass spectrometry (ICP-MS). Placental stress and mRNA expression of inflammatory genes were assessed using RT-PCR.

Results

A statistically significant negative association was noted between Se levels in the second trimester of pregnancy and mRNA expression of placental HO-1(β = −0.009, p < .01), HIF1α (β = −0.005, p = .010), GRP78 (β = −0.011, p < .001), CRP (β = −.007, p = .033) and CD68 (β = −0.006, p = .019). A negative association was noted between Se levels in cord blood and mRNA expression of placental HO-1 (β = −0.007, p = .004), HIF1α (β = −0.006, p = .005) and GRP78 (β = −0.009, p = .004). We found that prenatal Se status was associated with placental stress and mRNA expression of inflammatory genes.

Conclusion

Se deficiency during pregnancy, especially in the second trimester, leads to the production of OS and an increase in inflammatory mediators, affecting the growth and development of the fetus. Monitoring of pregnant women’s nutritional status is necessary to prevent nutritional imbalances and deficiencies in important micronutrients in the fetal.

Keywords:

• Selenium
• pregnant
• placenta
• oxidative stress
• inflammation
• mRNAs

Acknowledgments

We are most grateful to the participants of the MABC cohort study and the study team, research nurses, interviewers, research assistants, and other staff who have taken part in gathering the data of this study.

Ethics approval and consent to participate

The study was approved by Ethical Committee of Anhui Medical University (Number: 20131195). Written informed consent was obtained from all participants. All methods were performed in accordance with the relevant guidelines and regulations, including Declaration of Helsinki.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information. Data are available from the corresponding author.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant No. 82073566/82073578/82173532], the program for excellent young talents in college and university of Anhui province [gxyq2019014], and the Anhui Medical University Clinical Pharmacology and Pharmacology Co-construction Project [2020].