A study published February 18, 2026, in Neurology® found that women whose mothers were exposed to higher levels of lead during pregnancy performed worse on memory and thinking tests later in life.
This study doesn’t show that prenatal lead exposure causes cognitive decline, only that there is an association between exposure to higher lead levels before birth and lower scores on cognitive tests in adulthood.
Researchers turned to an unusual source to test lead exposure: baby teeth. Because teeth absorb lead as they form, baby teeth can show a record of lead exposure during pregnancy and early childhood.
From 1958 to 1972, parents in the St. Louis, MO, area donated their children’s baby teeth for a study that originally focused on radiation exposure. Decades later, researchers located many of those children, who are now in their early 60s, and asked them to complete cognitive tests.
The researchers compared lead levels in teeth to their scores on the memory and thinking skills tests. They found that female participants who had higher levels of lead exposure during the second trimester had lower scores on memory and thinking tests later in life, similar to the cognitive ability of someone three years older.
“Lead exposure in the United States peaked during the 1960s, ’70s, and ’80s, and many people born during that time are now reaching ages when changes in brain health become more noticeable,” said study author Ruby C. Hickman, PhD.
“While lead exposure has declined over recent decades, the Flint water crisis and recent lead contamination in cinnamon applesauce marketed to young children are examples of ongoing exposure problems in the United States, and lead exposure remains an issue globally as well,” Dr. Hickman added.
The study results show the importance of prevention and taking steps to protect the brain earlier to help support cognitive function later in life. Notably, most participants were white and grew up in households with higher education and income levels, which may limit how widely the results can be applied.
Key Takeaways
- Exposure to lead before birth may have lasting effects on brain health decades later.
- In this study, women whose mothers had higher lead exposure during the second trimester of their pregnancy scored lower on memory and thinking tests in their 60s.
- This study does not prove that exposure to lead before birth causes cognitive decline.
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