Washington state officials and health experts are concerned about a recent spike in reports of babies born with a rare defect, prompting an upcoming advisory committee to investigate why rates of the birth defects, which are fatal, are more than three times the national average.

The defects, investigated by NBC News in February, are a condition called anencephaly, where babies are born with parts of the brain or skull missing. Seven cases of the defect were reported in a remote area of eastern Washington in 2013. That number makes cases in the state over three times the national average for the fourth year straight, health officials told NBC News Tuesday.

The national rate for anencephaly is 2.1 cases for every 10,000 births. But in Washington there were 8.7 cases for the same number of births, according to NBC News. The regions where the cases occurred include Yakima, Benton and Franklin counties.

The Centers for Disease Control and Prevention along with state officials have decided to conduct "listening sessions" to hear concerns from locals about the health issue.

Andrea Jackman, whose daughter was born with spina bifida, a type of neural tube defect like anencephaly, told NBC News that it's not enough.

"It's good that they want to know everybody's thoughts, but what are they doing about it?" said Jackman, who lived in Yakima county when pregnant with her now 7-month old daughter. "Why are they going to put the time and money into chatting with people who don't know? Do the research."

There is no consensus as to the cause of the defects in eastern Washington. One theory is the low rates of folic acid supplement intake, which is associated with anencephaly and has been reported in the region.

Another theory says that anencephaly is brought on by exposure to pesticides, according to NBC News.

Leakage from the nearby Hanford nuclear plant is also said to be the cause of the defects, however there has not been enough research on the plant's connection to anencephaly, doctors told NBC News.