Researchers from Rutgers University have found that prenatal exposure to metals, including lead, arsenic, cobalt, and nickel, may disrupt the endocrine system. This may then lead to an increased risk for various diseases later in life.
While exposure to metals has already been linked to some problems at birth, including preterm birth (being born before 37 weeks of gestation), low birth weight, and preeclampsia in mothers, little has been known on how this happens.
Pre-existing data states that metal exposure is higher for pregnant women living in Puerto Rico than those in the continental United States. This is only exacerbated by extreme weather events, including hurricanes, droughts, and flooding, which may also elevate metal exposure. Consequently, women in Puerto Rico tend to have higher rates of preterm births than women in the continental US.
As such, for this study, researchers analyzed blood and urine samples alongside demographic and pregnancy-related data from 815 women enrolled in the Puerto Rico Test site for Exploring Contamination Threats (PROTECT) study. All in all, they analyzed 16 metalloids and nine maternal hormones from the data, which was taken at various intervals over a ten-year period.
In the end, they found that metals likely disrupt the endocrine system by altering prenatal hormone concentrations during pregnancy. In particular, they found that high arsenic blood concentrations correlated with an increase in corticotropin-releasing hormone (a key stress hormone) and a decrease in testosterone. Meanwhile, cobalt, manganese, and lead blood concentrations were linked to small increases in sex-hormone-binding globulin and progesterone.
These findings build on other research demonstrating that alterations in sex-steroid hormones during pregnancy are linked to inadequate fetal growth, and thus low birthweight. This is a concern as birth size is strongly linked to a children’s growth and risk of chronic disease, including obesity and cancer later on in life.
The study authors now say that future research should delve further into how essential metals relate to maternal and fetal health and how they affect endocrine function.