Selenium and Pregnancy

Maternal selenium status declines sharply during pregnancy. In selenium-poor regions of the world, the mother’s normal everyday intake of selenium is not adequate to meet the additional needs of the fetus. In such circumstances, maternal selenium status can reach critically low levels. Meanwhile, selenium supplementation has shown positive effects on the immune system, especially in pregnancy [Schomburg 2021].

Pregnant woman needs extra selenium
Biomarkers of selenium status decline in pregnancy and can reach critically low concentrations. Sufficiently high selenium status is important for an adequate immune response during pregnancy. Furthermore, selenium deficiency in pregnancy is associated with an increased risk of autoimmune disease, e.g., postpartum thyroid disorder.

In a letter to the Deutsches Ärzteblatt International, Mücke et al urge that doctors pay extra attention to the selenium status of patients in stressful situations, e.g., pregnancy, chronic or acute illness, or convalescence. They note that there is a clear risk of selenium deficiency during pregnancy. Also after giving birth, new mothers living in selenium-poor regions will likely need selenium supplementation. They will likely need extra selenium to cope with the challenging post-partum conditions [Mücke 2021; Schomburg 2021]. read more

Maternal Selenium Status and Offspring Risk of Autism and ADHD

A healthy pregnancy. Selenium is an essential trace element needed to support a healthy pregnancy. However, to date, studies of the mother’s selenium status and the child’s growth and development are scarce. Data from the Odense Child Cohort study in Denmark give researchers an opportunity to investigate the possible effects of the mother’s low selenium intake and low selenium status on the child’s neuro-development [Demircan 2023; Demircan 2024].

Dannebrog - Denmark's flag
Denmark is a country with selenium-poor soil and selenium-poor crops and fruits. The estimated mean daily intake of selenium in Denmark is 48 mcg/day with a 5th percentile intake of 27 mcg/day [Larsen 2004].
The pregnant women enrolled in the Odense Child Cohort study had borderline selenium deficiency status. Their serum selenium levels ranged from 57 to 75 mcg/L [Demircan 2024]. For the sake of comparison, note that Alexander & Olsen propose 110 mcg/L as an optimal selenium saturation level [Alexander & Olsen 2023]. read more

Low Selenium Status and At-Risk Pregnancies

Pregnant woman
Low serum selenium status (defined as below 80 micrograms per liter) during pregnancy is associated with increased risk of miscarriage, pre-eclampsia, pre-term births, and other adverse outcomes.

A recent review article presents the evidence that low selenium status in pregnant women may be implicated in the following complications [Duntas 2020]:

  • miscarriage
  • preeclampsia
  • pre-term birth
  • retarded fetus intrauterine growth
  • post-partum hypothyroidism and auto-immune thyroiditis

To ensure an optimal pregnancy outcome, Dr. Leonidas Duntas recommends that physicians take an individualized approach and prescribe dietary and supplemental selenium intakes that are tailored to the pregnant woman’s needs.

Why is Adequate Selenium Important for Pregnant Women?

Selenium is an essential trace element. Its intake and status in the blood plasma can vary considerably according to a number of factors [Duntas 2020]:

  • differences in diet and nutrition
  • differences in soil and plant selenium content
  • ethnic differences
  • genetic differences

Without a blood selenium test, it is not possible to know whether women planning a pregnancy have sufficient circulating selenium. The Mayo Clinic reports that the normal selenium concentration in adult human blood serum in the United States is 70 to 150 micrograms per liter with a population mean value of 98 micrograms per liter. read more