Outcomes of women with laboratory evidence of Zika infection in pregnancy

Abstract Background Zika virus (ZIKV) infection in pregnancy is a global health concern. With onset of local transmission, obstetricians in Miami-Dade County, FL, United States, are now in the unique position of providing care to both pregnant women with locally-transmitted and travel-associated ZIKV infections. This study provides data regarding the testing and pregnancy outcomes of women with laboratory evidence of ZIKV infection in pregnancy. Methods A retrospective chart review was conducted using laboratory records of ZIKV testing (PCR and IgM) completed from January through December 2016 at multiple tertiary care centers located in Miami-Dade County. Testing was based on CDC guidelines at time of testing, leading to heterogeneity in tests performed. Data was extracted from charts of women with positive ZIKV PCR in serum and/or urine or positive ZIKV IgM with confirmatory, pending, or insufficient PRNT results. Routine obstetrics parameters and the presence of fetal or neonatal abnormalities were recorded. Results Of the 2327 pregnant women screened for ZIKV, 88 (3.8%) screened positive with PCR and/or IgM in serum or urine. Of those women with positive ZIKV testing, 53 (60%) had no documented ZIKV symptoms and 40 (45%) had no known travel history outside of Miami-Dade County during their pregnancy. Sixty-six women had antenatal ultrasounds, 14 (21%) of which ever had a head circumference or biparetial diameter measurement less than the third percentile, but none showed evidence of intracranial calcifications. Fifty-four women with positive testing have delivered: 46 at term and 8 preterm. Fifty-four infants have been born to women with positive ZIKV testing; 2 infants (1.98%) had documented congenital abnormalities. One infant was born with clinically-defined microcephaly (1.9%) and intracranial calcifications and the other had only intracranial calcifications. Ninety-four positive IgM tests were sent to the CDC for confirmatory plaque reduction neutralization testing (PRNT). 49 PRNT tests returned positive (ZIKV titer ≥10), while 28 returned negative (ZIKV titer < 10), representing a false-positive rate of 30.4%. Conclusion As this epidemic persists, data from this unique cohort of pregnant women with both local and travel-associated ZIKV exposure contributes to the growing knowledge base regarding implications of ZIKV in pregnancy. Disclosures All authors: No reported disclosures