Birth Defects Study in WA Inconclusive
No common causes are found in a recent birth defects study in South Central Washington.
The state-led study into several cases of a rare birth defect in Yakima, Benton, and Franklin counties has revealed no common exposures, conditions, or causes. But prevention advice for brain development disorder includes prenatal vitamins with folic acid.
State and local public health investigators found no significant differences between women who had healthy pregnancies and those affected by anencephaly, a rare neural tube defect.
Anencephaly is a fatal birth defect that results from incomplete formation of the brain during the first month of pregnancy. An unusually high number of anencephaly cases in Washington prompted the study, which was led by the state Department of Health in co-operation with local health officials and the Centers for Disease Control and Prevention.
Typically, one or two anencephaly cases would be expected in about 10,000 annual births. The investigation found about eight cases per 10,000 births in the three-county area of Yakima, Benton, and Franklin.
Anencephaly and a related spinal cord disorder known as spina bifida are often 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.
The study examined medical records from January 2010 through January 2013 and looked at possible risk factors including family history, pre-pregnancy weight, health risk behaviors such as supplemental folic acid and medication use, and whether the woman’s residence received drinking water from a public or private source.
No significant differences were found when comparing cases of anencephaly with healthy births in the three county area.
Although the number of affected pregnancies was large for this area, larger numbers are often needed to identify causes. Medical record reviews might not have captured all information, preventing a cause from being identified.
The higher than expected number of anencephaly births in the region could be coincidental. Still, state health officials will keep monitoring births in the region through 2013 to see if the elevated number of affected pregnancies continues and if more can be learned about causes.
State and local health officials say women of childbearing age should follow the U.S. Preventive Services Task Force recommendation of taking 400-1000 micrograms of folic acid daily, either from foods fortified with folic acid or a supplement.
They also advise seeing a health care professional when planning a pregnancy or as soon as pregnancy is recognized, and making sure to provide a list of all medications and nutritional supplements that are being used.
Women who are pregnant or planning pregnancy should be sure that drinking water from private wells is tested at least annually for nitrate and bacteria. If levels exceed standards, an alternate source of drinking water should be used.