IMPORTANCE: Recent studies have reported an increase in the number of fetuses 
and neonates with microcephaly whose mothers were infected with the Zika virus 
(ZIKV) during pregnancy. To our knowledge, most reports to date have focused on 
select aspects of the maternal or fetal infection and fetal effects.
OBJECTIVE: To describe the prenatal evolution and perinatal outcomes of 11 
neonates who had developmental abnormalities and neurological damage associated 
with ZIKV infection in Brazil.
DESIGN, SETTING, AND PARTICIPANTS: We observed 11 infants with congenital ZIKV 
infection from gestation to 6 months in the state of Paraíba, Brazil. Ten of 11 
women included in this study presented with symptoms of ZIKV infection during 
the first half of pregnancy, and all 11 had laboratory evidence of the infection 
in several tissues by serology or polymerase chain reaction. Brain damage was 
confirmed through intrauterine ultrasonography and was complemented by magnetic 
resonance imaging. Histopathological analysis was performed on the placenta and 
brain tissue from infants who died. The ZIKV genome was investigated in several 
tissues and sequenced for further phylogenetic analysis.
MAIN OUTCOMES AND MEASURES: Description of the major lesions caused by ZIKV 
congenital infection.
RESULTS: Of the 11 infants, 7 (63.6%) were female, and the median (SD) maternal 
age at delivery was 25 (6) years. Three of 11 neonates died, giving a perinatal 
mortality rate of 27.3%. The median (SD) cephalic perimeter at birth was 31 (3) 
cm, a value lower than the limit to consider a microcephaly case. In all 
patients, neurological impairments were identified, including microcephaly, a 
reduction in cerebral volume, ventriculomegaly, cerebellar hypoplasia, 
lissencephaly with hydrocephalus, and fetal akinesia deformation sequence (ie, 
arthrogryposis). Results of limited testing for other causes of microcephaly, 
such as genetic disorders and viral and bacterial infections, were negative, and 
the ZIKV genome was found in both maternal and neonatal tissues (eg, amniotic 
fluid, cord blood, placenta, and brain). Phylogenetic analyses showed an 
intrahost virus variation with some polymorphisms in envelope genes associated 
with different tissues.
CONCLUSIONS AND RELEVANCE: Combined findings from clinical, laboratory, imaging, 
and pathological examinations provided a more complete picture of the severe 
damage and developmental abnormalities caused by ZIKV infection than has been 
previously reported. The term congenital Zika syndrome is preferable to refer to 
these cases, as microcephaly is just one of the clinical signs of this 
congenital malformation disorder.