Zika Birth Defect Rates Correlate to Time of Infection in Pregnant Women

Defects occurred more frequently when Zika virus infection occurred in the first trimester
Defects occurred more frequently when Zika virus infection occurred in the first trimester

HealthDay News — Seven percent of pregnant women with symptomatic Zika virus (ZIKV) infection have birth defects possibly associated with ZIKV infection, according to a study published in the March 15 issue of the New England Journal of Medicine.

Bruno Hoen, MD, PhD, from INSERM Centre d'Investigation Clinique in France, and colleagues enrolled pregnant women with polymerase chain-reaction confirmed symptomatic ZIKV infection in a prospective cohort study conducted in the French territories in the Americas. Data from 555 fetuses and infants in 546 pregnancies were included in the analysis. 

Related Articles

The researchers found that 5.0% of the fetuses and infants were not carried to term or were stillborn and 527 were born alive. In 39 fetuses and infants (7.0%), neurologic and ocular defects possibly associated with ZIKV infection were seen; 10 of these were not carried to term (termination for medical reasons), 1 was stillborn, and 28 were live-born. Thirty-two fetuses and infants (5.8%) had microcephaly, of whom 9 had severe microcephaly. Neurologic and ocular defects were more common when ZIKV infection occurred in the first versus during the second or third trimester (12.7 versus 3.6 and 5.3%, respectively).

"Among pregnant women with symptomatic, PCR-confirmed ZIKV infection, birth defects possibly associated with ZIKV infection were present in 7% of fetuses and infants," the authors write. "Defects occurred more frequently in fetuses and infants whose mothers had been infected early in pregnancy."

Abstract/Full Text
Editorial