ZIKV RNA is detectible but its presence does not correlate with fetal outcomes.

<p>(<b>A-D</b>) Pregnant dams at E9.5 were infected with 3.4, 1, or 0.34 × 10⁵ PFU of ZIKV by intravenous route, and sacrificed 8 dpi at E17.5. ZIKV RNA levels were measured by quantitative real-time PCR. (<b>A</b>) ZIKV RNA levels in the spleens of dams infected with 3 doses of ZIKV. (<b>B</b>) ZIKV RNA levels in the liver, kidney, brain or serum in dams infected with 3.4 × 10⁵ PFU. (<b>C</b>) ZIKV RNA levels of all placental samples carried by dams infected with 3 doses (left panel), or placental residues or remaining intact embryos and their corresponding placentas carried by dams infected with 3.4 × 10⁵ PFU (right panel). (<b>D</b>) Summary of embryonic outcome in relation to viral RNA presence. The table depicts the numbers and percentages of embryos that were affected (Aff) or normal (N) in the absence (-) or presence (+) of detectable ZIKV RNA by real-time PCR in placentas, corresponding embryos, or both. Affected embryos include those which suffered demise/resorption, or exhibited any sign of growth restriction, malformation, or anatomical developmental defect by gross morphological examination. Chi-square test revealed no statistically significant association between viral RNA presence and embryonic outcome (p = 0.97). (<b>E</b>) Pregnant dams were infected with 3.4 × 10⁵ PFU of ZIKV at E9.5 or E12.5, and sacrificed 5 dpi at E14.5 or E17.5, respectively. ZIKV RNA levels in the maternal spleen, placenta or embryonic head were measured by quantitative real-time PCR. (<b>A-C</b> and <b>E</b>) Data shown are median with interquartile range. Dotted line depicts the limit of detection. (ns, not significant by Mann-Whitney test). Number of samples in each group is listed in the parentheses. Data for all panels are pooled from 2–5 independent experiments.