Health officials investigating a spike in cases of a fatal birth defect in central Washington state have found no common cause linking the cases, according to a new report from the Centers for Disease Control and Prevention (CDC).
The investigation began last year when a local hospital alerted the state health department to an unusually high number of babies born with a rare birth defect called anencephaly, in which parts of the baby’s brain and skull are missing.
The investigators identified 23 women in a three-county area whose babies had anencephaly between January 2010 and January 2013. The anencephaly rate was more than 8 per 10,000 births, which is four times higher than the national average of one or two cases in every 10,000 births, according to the report. [7 Ways Pregnant Women Affect Babies]
The researchers compared the group of 23 women, along with four other women whose babies had birth defects similar to anencephaly, with a control group of 108 women living in the same counties whose babies were born without birth defects and who were treated at the same clinics.
Examining medical records, the researchers looked at possible risk factors for anencephaly, including family history, women’s weight before pregnancy, their occupations, their smoking and alcohol use, health conditions during pregnancy, medication use (including over-the-counter remedies, vitamins and folic acid supplementation) and whether the woman’s residence received drinking water from a public or private source.
However, no common exposures, conditions or causes were found. The researchers didn’t find any significant differences between women who had healthy pregnancies and those affected by anencephaly, according to the report.
Babies born with anencephaly are missing parts of the brain, and are usually blind, deaf and unconscious. If the babies are not stillborn, they usually die within hours of birth. Anencephaly occurs during the third and fourth weeks of pregnancy.
The U.S. Preventive Services Task Forcerecommends women ensure their diet includes folic acid (B9 vitamin), an essential nutrient that people need to consume through foods or supplements. Babies born to women who have enough folic acid in their bodies before and during pregnancy have a reduced risk of major birth defects of the brain and spine, studies have shown.
Women of childbearing age should consume 400 to 1,000 micrograms of folic acid every day, the task force recommends. Foods rich in the vitamin include spinach, asparagus, turnip greens, lettuce beans, peas and lentils and egg yolks.
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