A new study on Zika, a mosquito-borne virus which may increase the risk of microcephaly and other developmental disorders in fetuses of pregnant women afflicted with the virus, found that “despite mild clinical symptoms, Zika virus infection during pregnancy appears to be associated with grave outcomes, including fetal death, placental insufficiency, fetal growth restriction and central nervous system injury.”
The study, published on March 4 in The New England Journal of Medicine, tracked 88 pregnant women in Rio de Janeiro from September 2015 through February 2016, 72 of whom tested positive for Zika virus. Doctors performed ultrasounds on 42 of the women in the Zika positive group and all of the women in the Zika-negative group. Of the 16 Zika-negative women, none had abnormalities. Of the 42 Zika-positive women, 12 of them (29 percent) had fetuses with abnormalities.
The study also found that fetuses had developmental problems even if mothers caught the disease late in their pregnancies. The World Health Organization has officially advised pregnant women to avoid areas where Zika is spreading, as well as warning that unprotected sex with partners who have been in Zika-afflicted areas can also transmit the virus.
In Norway, two pregnant women tested positive for Zika after travelling in Latin America. The Norwegian Institute of Public Health recently tested dozens of people for the virus, mostly pregnant women.