Conception Timing Linked to IQ

From: Robina Suwol
Date: 16 May 2007
Time: 10:05:03
Remote Name:


Conception timing linked to IQ

Published: Friday, May 11, 2007

 NEW YORK -- The time of year a woman conceives may influence the future academic performance of her child, according to a new study.

 Researchers compared test scores of 1,667,391 students in grades 3 through 10 with the month in which the children had been conceived.

 They found that children conceived May through August scored significantly lower on math and language tests than youngsters conceived during other months of the year.

 ****The correlation between test scores and conception season held regardless of race, gender and grade level.

 Why might this be? Dr. Paul Winchester of Indiana University School of Medicine who led the study, said the evidence points to environmental pesticides, used most often in the summer months, as a possible player. 

The lower test scores correlated with higher levels of pesticides and nitrates in the surface water (nearby streams and other bodies of water) during that same time period, he said. 

"Exposure to pesticides and nitrates can alter the hormonal milieu of the pregnant mother and the developing fetal brain," Winchester, who reported the findings at the Pediatric Academic Societies' annual meeting, said in a statement. 

Past research has linked exposure to pesticides and nitrates to low thyroid hormone levels ("hypothyroidism") in pregnant women and hypothyroidism in pregnancy has been tied to lower intelligence test scores in offspring. While the current findings do not prove that pesticides and nitrates contribute to lower test scores, Winchester said they strongly support such a hypothesis. 

"A priority there should be no reasons particularly why the month of conception should change your (test) scores," he added in an interview, "and yet from our chain of evidence our hypothesis was that if pesticides do alter the friendly environment of the developing fetus then that might be reflected in lower scores. And unfortunately that's what we found."

Last changed: May 16, 2007