Mounting evidence says DEET safe for pregnant women if applied correctly

Experts say DEET, used in insect repellents to deter biting mosquitoes, is safe for pregnant women and their unborn children, if used correctly, according to an April 4 New York Times article. Even though research is scant, "it makes sense to use DEET to protect yourself from something we know is truly unsafe, like Zika," Laura E. Riley, MD, a specialist who works with high-risk pregnancies and infectious disease at Massachusetts General Hospital, said in the article. According to the CDC, the Zika virus, which is transmitted by mosquito bites and spreading, has been linked to a serious birth defect of the brain in babies of mothers who contract the virus while pregnant. The World Health Organization said the Zika virus, found in Africa, the Americas, Asia and the Pacific, is a public health emergency of international concern. Insect repellents that contain DEET offer the best protection against mosquito bites, according to the CDC. DEET refers to the chemical, diethyl-m-toluamide, the active ingredient in insect repellent. Few published studies address the effects of DEET in pregnant women and their children -- and none of the studies involved pregnant women in the first trimester, the period when most birth defects occur, according to the New York Times article. Among the latest studies is one done in 2010 by CDC researchers who analyzed the presence of certain pesticides in the blood of 150 pregnant women and their umbilical cords in New Jersey. Although DEET was detected, senior author Mark Robson, PhD, MPH, said the birth weight was normal for all infants born to the pregnant women in the study, according to the New York Times article. Robson is a professor at Rutgers University in New Jersey. An earlier study, published in the American Journal of Tropical Medicine and Tropical Hygiene, showed the daily application of DEET on women in their second and third trimesters of pregnancy resulted in "no adverse effects on survival, growth or development at birth, or at one year," according to the study's abstract. The study's lead author, Rose McGready told the New York Times "an important missing component" of the study is that it did not include the first trimester. Among the areas hardest hit by the Zika virus is Puerto Rico. The CDC expects the virus will have infected one-fourth of the people there within a year. The University of Michigan School of Public Health is tracking the amount of pesticides including DEET in 1,000 pregnant women in Puerto Rico to determine the chemical's safety, according to the New York Times article. The USEPA issued a statement in 2014 saying when used properly, the DEET containted in insect repellents does not pose a risk to human health. No vaccine or medications are available to prevent Zika virus infection, according to the CDC. It recommends pregnant women consider postponing travel to areas where the virus is present, and if she goes, to follow steps to avoid mosquito bites, including applying repellent with DEET as directed. To comment, email [email protected].