High rate of neurological birth defects in three rural Washington counties defies explanation

Health officials and researchers can't figure out why babies born to women in three counties in rural southern Washington are experiencing a high rate of anencephaly, "a heart-breaking condition in which they’re born missing parts of the brain or skull," Jonel Aleccia reports for NBC News. During a three-year period leading up to January 2013, the state health department and the federal Centers for Disease Control and Prevention counted nearly two dozen cases of birth defects in Yakima, Benton, and Franklin counties in southern Washington, a rate four times the national average. (NBC photo by James Cheng: A four-month old in Washington with spina bifida) 

Since January 2013, one local genetic counselor has counted an additional eight to nine cases of "anencephaly and spina bifida, another birth defect in which the neural tube, which forms the brain and spine, fails to close properly," Aleccia writes. A CDC report released last year examined 27 women in the three counties whose pregnancies had the defect and 108 experiment "control" patients at the same prenatal clinics; they found that 23 cases included anencephaly, a rate of 8.4 per every 10,000 births, well above the national average of 2.1 per every 10,000 births.

The researchers "examined where the women worked, what diseases they had, whether they smoked or drank alcohol, what kind of medications they took and other factors," Aleccia writes. "They looked at where they lived and whether they got their water from a public source or a private well. They looked at race and whether the problem was more pronounced in the area's migrant farm workers or in other residents. In the end, there was nothing — 'no common exposures, conditions or causes,' state officials said — to explain the spike." (Read more)

Twelve cases of anencephaly were reported in the tri-county area in 2012, up from two in 2010 and seven in 2011, Molly Rosbach reports for the Yakima Herald-Republic. A state health department news release stated: “State and local public health investigators found no significant differences between women who had healthy pregnancies and those affected by anencephaly."

Officials said a key to preventing anencephaly is to take folic acid daily, and to avoid nitrates in water. "Women with higher-than-recommended intake of nitrates in their drinking water were more likely to experience several different birth defects, including anencephaly," according to a Texas A&M study, Rosbach writes. Nitrates, which are used in fertilizer, are more prevalent in agricultural regions. (Read more)