Additional cases of a mysterious and devastating birth defect have been reported in three Central Washington counties in the past year, but state health officials said this week the problem may not be as severe as initially feared.
Forty-four cases of anencephaly have been detected in Benton, Franklin and Yakima counties since 2010, including four reported since August 2015. It’s a rare and fatal defect in which babies are missing part of their brain and skull.
Studies in recent years warned that the rate of the defect in those Washington counties was four or five times higher — or more — than the national estimate of 2.1 cases per 10,000 live births reported by the Centers for Disease Control and Prevention.
Cases in the area climbed to nine per year in 2012 and 2013, reaching a rate of 11.1 per 10,000 births. In 2015, five cases were reported, a rate of 6.0 per 10,000 births. Two cases have been reported with due dates in 2016 and one due in 2017.
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But Dr. Cathy Wasserman, a state epidemiologist, said Washington officials could simply be looking harder for the problem.
“Our reported rates are higher than what’s been reported (by others), but depending on the definition, they’re lower than the fourfold increase,” Wasserman said during a meeting of the state’s anencephaly task force.
Starting in September, chips and tortillas made with corn masa fortified with the B vitamin will be available on store shelves in the United States, including Washington state.
Other states reporting to the National Birth Defects Prevention Network, which provides the data behind the federal estimate, may be counting cases differently. About half of the cases in Washington were detected in fetuses of less than 20 weeks gestation, versus about a quarter at that early stage in the federal estimate.
“We think they suggest that we are ascertaining cases earlier than in other locations and possibly capturing cases that may be missed in other active registries,” she said.
That doesn’t mean that the Washington situation isn’t concerning, but it does add to the difficulty of determining what may causing it, said Peter Langlois, a senior epidemiologist with the Texas Birth Defects registry, who is advising local officials.
“Maybe the rates aren’t as high as we had initially worried, but it’s still worth looking into,” he said.
State officials have been criticized by outside experts, who said they should have worked harder to uncover possible environmental or genetic links to the defects.
As of October, officials had reached out to conduct interviews with 34 of 64 mothers of infants with any type of neural-tube defect, which occur in early pregnancy when the tube that forms the brain and skull doesn’t form properly.
They approached 22 of 41 women with infants with anencephaly, but have interviewed just 12.
In Texas, in 22 years, we’ve had over 100 different birth-defect cluster investigations. In the vast majority, we never find out what caused them.
Epidemiologist Peter Langlois
From the interviews and the investigation, there’s no clear clue about what may be causing the defects, Wasserman said. A new analysis, reported Tuesday, showed no link between the defects and whether families lived close to agricultural-production areas. The women interviewed all took prenatal vitamins that include folic acid, the best known way to prevent neural-tube defects.
Still, state workers will continue to reach out to girls and women of childbearing age in the region to let them know that the vitamins could help prevent birth defects.
And, starting in September, chips and tortillas made with corn masa fortified with the B vitamin will be available on store shelves in the United States, including Washington state, officials with the March of Dimes said. Gruma, the largest producer in the U.S. of corn-masa products, agreed to add the supplement after an FDA ruling in April.
The agency allowed manufacturers to add folic acid to corn-masa products to prevent birth defects. Smaller producers may already have taken action, a FDA spokeswoman said. All products that have been fortified must list folic acid on the ingredient label.
Health officials will continue to monitor the defects in the three Washington counties for at least another year, Wasserman said.
But they may wind up no closer to an answer, Langlois noted.
“In Texas, in 22 years, we’ve had over 100 different birth-defect cluster investigations,” he said. “In the vast majority, we never find out what caused them.”