Washington state authorities are baffled after an investigation into the spike in a rare birth defect in several neighboring counties has failed to uncover a common cause.
The counties of Yakima, Benton and Franklin all reported an unusually high rate of anencephalic pregnancies between January 2010 and January 2013.
The Department of Health in conjunction with local health authorities and the Center for Disease Control and Prevention examined records to determine risk factors in the cases of anencaphaly but has not found a common cause.
Rare: Anencephaly only affects one or two births per 10,000 in the U.S.
Anencephaly occurs between the third and fourth weeks of pregnancy. During that time, the neural tube is supposed to close and fold over to form the brain and spinal cord of the fetus.
This process fails to occur in anencephalic pregnancies, resulting in the absence of a large portion of the brain, skull and scalp.
Babies born with anencephaly are usually blind, deaf, unconcious and unable to feel pain. They are usually stillborn but in rare cases they may survive longer.
The rate of anencephaly is one or two per 10,000 births. The rate in the Washington state counties is eight per 10,000 births.
The condition: A baby born with anencephaly lacks the telencephalon, encompassing the part of the brain responsible for cognition
Baffled: Authorities are unsure why the Washington counties of Yakima, Benton and Franklin are reporting higher than average rates of anencephaly
It's a significant jump for such a rare condition and prompted the Department of Health study.
According to the Department, anencephaly and a related spinal cord disorder, spina bifida, can be caused by a lack of the B-vitamin folic acid in the mother’s diet.
Other factors include certain medications, diabetes, pre-pregnancy obesity, or previously having a child with a neural tube defect.
Defect: Anencephaly occurs in the early weeks of pregnancy
In Washington, health investigators looked at family history, pre-pregnancy weight, health risk behaviors such as supplemental folic acid and medication use, and whether the mother’s residence received drinking water from a public or private source.
They found no common exposures, conditions or causes among the cases of anencephaly, and no significant differences between healthy pregnancies and anencephalic births.
Health Department officials have said the higher rate of anencephaly could be pure coincidence.
The Department will continue to monitor births in the region throughout 2013 to see if the rate of anencephaly remains raised, and whether any further causes can be identified.
Dr. Joanne Stone, director of Maternal Fetal Medicine at Mount Sinai Medical Center in New York, told ABC that anencephaly can be caused by a combination of genetic and environmental factors.
'The interesting thing with this study is that they looked at different factors, and women's histories, and obesity, and at medical history and couldn't find anything that stood out,' she said.
'Could it be a fluke? We don't know. It could take time to uncover some sort of [unusual] exposure.'
According to the U.S. Preventive Services Task Force, women of child-bearing age should take 400-1000 micrograms of folic acid daily, either from foods fortified with folic acid or a supplement
Read more: http://www.dailymail.co.uk/news/article-2368654/High-rate-birth-defects-Washington-state-officials-stumped.html#ixzz2ZPjNiFBZ
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