Brazil study strengthens link between Zika virus, birth defects

In a study of pregnant women in Brazil, nearly 30 percent of those infected with Zika virus had babies with fetal abnormalities, researchers report March 4 in the New England Journal of Medicine.

Zika virus is the leading suspect for what’s causing a spike in certain birth defects reported in Brazil. Scientists have previously found traces of Zika in the brains of fetuses with microcephaly (a birth defect that leaves babies with smaller-than-normal heads). And one study has reported that the virus can infect and kill a cell type crucial to developing brains (SN Online: 3/4/16).

The new study enrolled 88 pregnant women from Rio de Janeiro who had developed a rash (a sign of Zika infection). They tracked the women throughout their pregnancies; so far, eight have given birth. Of the 42 women who both tested positive for Zika and received fetal ultrasounds, 12 of the women’s babies had abnormalities (including small heads, damaged brain tissue, and low levels of amniotic fluid).

Despite mild clinical symptoms, Zika infection during pregnancy appears to be linked with grave outcomes, the authors write.