Around 6 percent of fetuses or infants born to U.S. women with laboratory evidence of possible recent Zika infection showed evidence of Zika-related birth defects, according to a study published in JAMA.
Researchers examined the U.S. Zika Pregnancy Registry, a collaboration between the CDC and state and local health departments. They studied 442 completed pregnancies with maternal, fetal or infant laboratory evidence of possible recent Zika virus infection and outcomes reported in the United States from January 15 to September 22, 2016.
Here are six insights:
1. Of the 442 completed pregnancies, 26 showed evidence of birth defects potentially related to Zika virus.
2. Birth defects were reported for 16 of 271 pregnant women showing no symptoms of Zika infection, and 10 of 167 pregnant women showing symptoms.
3. Of the 26 affected fetuses or infants:
• Four had microcephaly and did not report neuroimaging
• 14 had microcephaly and brain abnormalities
• Four had brain abnormalities without microcephaly
4. Reported brain abnormalities included intracranial calcifications, corpus callosum abnormalities, abnormal cortical formation, cerebral atrophy, ventriculomegaly, hydrocephaly and cerebellar abnormalities.
5. Infants with microcephaly represent 4 percent of completed pregnancies.
6. Among women who showed symptoms of Zika infection in the first trimester, 11 percent of fetuses or infants had evidence of Zika-associated birth defects.