Toxic metals and essential trace elements in placenta and their relation to placental function

Area of Science:

• Environmental toxicology
• Reproductive biology
• Perinatal health

Background:

• Placental function is critical for fetal development.
• It can be compromised by malnutrition and environmental exposures.
• Understanding trace element impacts is vital for healthy pregnancies.

Purpose of the Study:

• To investigate the effects of toxic and essential trace elements on placental function.
• To assess associations between placental element concentrations and placental efficiency, relative telomere length, and mitochondrial DNA copy number.

Main Methods:

• ICP-MS analysis of toxic (Cd, Pb, Hg, Co) and essential (Cu, Mn, Zn, Se) elements in placentas from 406 pregnant women.
• Measurement of placental weight, birth weight, placental efficiency, relative telomere length (TL), and mitochondrial DNA copy number (mtDNAcn).
• Statistical analysis using regression models and Bayesian kernel machine regression (BKMR), adjusted for covariates.

Main Results:

• Selenium was inversely associated with placental weight; lead showed a similar inverse association at low selenium levels.
• Manganese was positively associated with placental weight but inversely with placental efficiency.
• Cobalt was inversely associated with mtDNAcn, while all essential elements positively correlated with mtDNAcn, both individually and jointly.

Conclusions:

• Lead negatively impacts placental weight, and cobalt reduces placental mitochondrial DNA copy number.
• Essential elements, as a group, enhance placental mitochondrial DNA copy number.
• Manganese may increase placental weight, but not birth weight; selenium's inverse association with placental weight might indicate increased fetal transport.