Herbicide Linked to an Increased Risk of a Congenital Abnormality

Choanal atresia is the congenital obstruction of the nasal passage due to presence of a membrane or boney tissue, this disorder blocks the nasal passage. This has serious affects on the baby's ability to breathe. Choanal atresia is the most common nasal abnormality and occurs in about 1 of every 7000-10,000 births.

 The researchers at the Baylor College of Medicine and other Texas institutions have found a common herbicide used in the United States that triggers this congenital abnormality.  

The study that is led by Dr. Philip Lopo, assistant professor of pediatrics -- hematology/oncology at BCM and Texas Children's Cancer Center, will be published in the Journal of Pediatrics.

According to Lupo, a few risk factors have for the choanal atresia has been identified. The chemicals that disrupt the maternal endocrine system may be associated with risk.

In order to carry out the study the researchers focused on atrazine, one of the most commonly used herbicide in the United States that is especially for corn crops. This is considered to be an endocrine disrupter. They worked on the data that was collected from the Texas birth Defects Registry.

Choanal atresia symptoms includes: child breathing through mouth, Inability to nurse and breathe at same time, Inability to pass a catheter through each side of the nose into the throat, Persistent one-sided nasal blockage or discharge. 

"Endocrine disrupters aren't fully understood, but it is believed they interfere with or mimic certain hormones, thereby blocking their proper function and potentially leading to adverse outcomes," Lupo said.

The researchers noticed that mothers who lived in Texas counties with the highest levels of estimated atrazine application were 80 percent more likely to have children with choanal atresia or stenosis compared to women who lived in the counties with the lowest levels. Choanal stenosis is a less severe form of the condition.

"Our results warrant more detailed exploration before any public health or policy-related recommendations are made," Lupo said, "but this study is a good first step in trying to understand the origin of this birth defect, including a possible role of atrazine."

The study was funded in part by the Centers for Disease Control and Prevention-funded Texas Center for Birth Defects Research and Prevention through a cooperative agreement with Texas Department of State Health Services as well as the Title V Office of Texas DSHS.