(OLYMPIA, Wash.) -- A high rate of birth defects has confounded Washington health officials, who have been unable to identify a cause.
A report released Tuesday by the Washington State Department of Health said that, since 2010, the neighboring counties of Yakima, Benton and Franklin have had an unusually high number pregnancies affected by the birth defect anencephaly, which results in a newborns' brains being severely underdeveloped.
In the U.S., there are approximately one or two expected cases of anencephaly for every 10,000 annual births. However, in the three named Washington counties -- with a total population of approximately 515,000 -- the health department found that there was an abnormally high number of cases reported from January 2010 to January 2013, with approximately eight cases of anencephaly for every 10,000 births.
Anencephaly is a birth defect, almost always fatal, where the neural tubes in the fetus do not close properly. As a result, the forward part of the fetus' brain is not developed and the other part of the brain is exposed to amniotic fluid, causing further damage. Most fetuses that develop the defect are stillborn. Those who survive usually die shortly after being born.
Anencephaly can be caused by a pregnant woman lacking enough of the B-vitamin folic acid in her diet. However, local Centers for Disease Control and Prevention and state health department officials found that there was not a significant difference in the amount of supplemental folic acid taken by women whose pregnancies were affected by the birth defect and those who had healthy pregnancies.
In addition to looking at supplemental folic health, the department also looked for variations in other risk factors, including family history, pre-pregnancy weight and whether or not the mothers drank water from a private or public source. Officials found no significant differences among the risk factors when comparing anencephaly and healthy births in the region.
Donn Moyer, a spokesman for the Washington State Department of Health, said anencephaly is still an extremely rare disease and finding a common cause for a handful of cases a year can be difficult to determine.
"There's one region in the state [that's had a spike]," said Moyer. "It could be complete coincidence, but we didn't want to shrug our shoulders and [say it's a coincidence.]"
Moyer said the department would continue to analyze information until at least the end of the year and then reassess the situation after examining 2013 rates of anencephaly in that region.
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