An Indiana scientist makes a rather provocative argument that exposure to pesticides in the womb can explain why Indiana babies conceived in July-August (Born March and April?) have lower achievement scores than the other kids.
Dr. Winchester and colleagues linked the scores of the students in grades 3 through 10 who took the Indiana Statewide Testing for Educational Progress (ISTEP) examination with the month in which each student had been conceived. The researchers found that ISTEP scores for math and language were distinctly seasonal with the lowest scores received by children who had been conceived in June through August.
“The fetal brain begins developing soon after conception. The pesticides we use to control pests in fields and our homes and the nitrates we use to fertilize crops and even our lawns are at their highest level in the summer,” said Dr. Winchester, who also directs Newborn Intensive Care Services at St. Francis Hospital in Indianapolis.
“Exposure to pesticides and nitrates can alter the hormonal milieu of the pregnant mother and the developing fetal brain,” said Dr. Winchester. “While our findings do not represent absolute proof that pesticides and nitrates contribute to lower ISTEP scores, they strongly support such a hypothesis.”
Well, that is a bold leap of faith, and use of a correlation=causation argument that I don’t appreciate in most cases. Has this kind of work been done in other countries, or in urban environments without pesticide use?
I am sure that many chemicals have subtle, but significant effects on developing fetuses. And the chemicals the authors mention have links with hypothyroidism..
Nitrates and pesticides are known to cause maternal hypothyroidism and lower maternal thyroid in pregnancy is associated with lower cognitive scores in offspring.
There is a link, but without further data, I think the conclusions are a stretch. But, something to keep in mind I guess if you live in Indiana and want to plan a baby!
Disclaimer: I was conceived in June, and was in the upper echelons of achievement through school. So, by the power of personal experience, I am predisposed to scepticism. OTH, I grew up in a big city with consistently high pollution levels throughout the year and not much pesticide exposure.