BY CLARE HOWARD

Glyphosate, the most heavily used weed killer in the United States, was found in 91 percent of pregnant women tested in a recent study conducted by Dr. Paul Winchester, medical director of the neonatal intensive care unit at Franciscan St. Francis Hospital in Indianapolis.

Glyphosate is the main ingredient in Roundup produced by Monsanto and was determined to be a probable human carcinogen by the World Health Organization in 2015.

Pre-term, low-weight births are a key factor in birth defects, and Winchester’s study found higher levels of glyphosate correlated with shorter pregnancies.

Winchester said women in the Midwest are nearly all exposed to glyphosate while pregnant and that means their fetuses are exposed.

More than 300 million pounds of glyphosate are used in the United States each year. That’s up from about 11 million pounds in 1987. The spike in use is due to the introduction of genetically engineered crops modified to withstand pesticides. Glyphosate is also sprayed on wheat and grains just prior to harvest to facilitate drying.

The pesticide is heavily used in the Midwest on corn, soybeans and wheat. It is also used in many residential lawn care formulations.

It is not widely found in water, but is found in most food. Despite that, the EPA has ceased testing food for glyphosate residue.

In addition to being a probable human carcinogen, glyphosate is an endocrine disrupting chemical.

Prior to Winchester’s research, glyphosate studies had used rodent models that found exposure had adverse effects for generations of offspring. This epigenetic mechanism means exposure of a female can adversely affect offspring for generations. Winchester’s research used urine samples obtained from 69 pregnant women at a private obstetrical practice. He expects to expand the research sampling later this year.

Winchester said it is critical for policy makers to address this large scale fetal exposure.