Fetal exposure to toxic metals in intrauterine blood transfusions (IUTs) could be a significant public health concern, in particular for fetuses with hemolytic disease of the fetus and newborn (HDFN), according to a recently published commentary in the Journal for the European Society for Pediatric Research.
“Even at low doses with prolonged exposures, toxic metals can bio-accumulate leading to poor neurodevelopmental outcomes, with teratogenic and carcinogenic potential, and multiple organ damage including liver, kidney, blood, and brain,” the authors wrote.
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The heavy metals most commonly associated with neurotoxicity in fetuses and newborns are lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg). The authors aimed to determine the concentration of these substances in transfusion bags, umbilical cord samples, and maternal blood samples of 30 pregnancies that received IUTs for HDFN. The study included a south Arabian population.
The authors sampled over 120 transfusion bags and every bag had detectable levels of one or more toxic metals. Furthermore, there was a direct correlation between the concentrations of Hg, Cd, and As in transfusion bags and the concentration of these substances in the umbilical cord. The authors found a similar correlation only for Cd regarding maternal blood samples.
The cord samples from 17 fetuses had a hazard index over 1, which indicates a substantial health risk due to high toxic metal concentration. Pb was the toxic metal most commonly associated with a high health risk, followed by Hg and Cd.
Heavy metal toxicity as a global issue
The authors remarked that heavy metal toxicity is not an isolated problem in the South Arab population. A report by the American Association of Poison Control Centers (AAPCC) revealed over 8000 exposures to heavy metals in the year 2021, and approximately 3000 were in children under the age of 6.
Another study by the United States National Health and Nutrition Examination Survey (NHANES) reported that over 40% of women in their reproductive age were exposed to heavy metals. A study in the United States, including 75 preterm newborns, showed that over 90% of transfusion bags had detectable Pb levels.
“Based on this evidence, along with the described detrimental impact of environmental toxins, there is a critical need to monitor perinatal exposures and long-term outcomes on a large scale, with a focus on neurodevelopmental outcomes,” the authors concluded.
