Adverse prenatal and early postnatal infant outcomes
In summary, pregnancy losses and/or birth defects potentially related to
ZIKV in newborns occurred in 43/511(8.4%) symptomatic mothers while
microcephaly or other CNS malformations were diagnosed in 25.0%(1/4) of
the stillbirths and 3.9%(19/489)[CI95%:2.5-5.9] of the live-born
infants. If only the typical CZS phenotype in infants without
co-morbidities was considered, then 12/489(2.9%;CI95%:1.7-4.7) infants
would be affected by the intrauterine ZIKV-infection or
13/513(2.5%;CI95%:1.5-4.3) fetuses.
Tables S1 and S2 show the overall characteristics and pregnancy outcomes
in 511 women. There were 24(4.7%) pregnancy losses. Postmortem
examination of one of the four stillbirths (34 weeks) showed severe CNS
malformations. There was one stillbirth of unknown cause. The remaining
three fetal losses had no malformations and were likely secondary to
premature membrane rupture or placental abruption. Of the remaining 487
women, there were 489 live births.
As shown in Figure 1, of the live-born infants, 33(6.7%;CI95%:4.8-9.3)
had one or more major abnormalities, and 19(3.9%;CI95%:2.5-5.9) had
findings potentially related to ZIKV infection (Table 1). Except for
three infants (including two that died shortly after birth due to severe
CZS anomalies), those with potential ZIKV infection underwent additional
postnatal neuroimaging. Malformations of cortical development, brain
volume loss, ventriculomegaly, and calcifications were found. All five
infants with severe and 16.7%(1/6) of those with moderate microcephaly
had eye abnormalities. Two infants without microcephaly had neurological
dysfunctions and were diagnosed with brain abnormalities. Of the 17
infants screened for hearing loss, one failed, but we could not confirm
this result. Of the 19 infants with findings potentially related to ZIKV
infection, 4(21%) were categorized as mild/moderate and 15(79%) as
severe1.