thrombosis(2) Evidence(2) vascular thrombosis(2) COVID-19(2) Pregnancy(2) finding(2) fetal(2) Placenta(2) Vascular(2) villitis(2) pathology(2) mother(2) positive(2) 2019-nCoV(2) clinical information(2) tested(2) ACE2(1) children(1) SARS-CoV-2(1) immunohistochemistry.(1)