REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Anti-CD63 Antibody	BD PharMingen	Cat# 556019; RRID:AB_396297
Anti-AGO2 Antibody	Abcam	Cat# ab57113; RRID:AB_2230916
Anti-PLAP Antibody	Abcam	Cat# ab118856; RRID:AB_10900125
Biological Samples
Maternal Serum	UCSD Placental Dysfunction Clinic
Maternal Serum	Sera Prognostics Repository
Critical Commercial Assays
miRNeasy micro kit	QIAGEN	217084
mirVana miRNA Isolation Kit, without phenol	ThermoFisher Scientific	AM1561
RNA Clean & Concentrator-5	Zymo Research	R1013
DNA Clean & Concentrator-5	Zymo Research	D4013
Quant-iT RiboGreen RNA Assay Kit	ThermoFisher Scientific	R11490
Quant-iT PicoGreen dsDNA Assay Kit	ThermoFisher Scientific	P11496
Agilent RNA 6000 Pico Kit	Agilent Technologies	5067-1513
Agilent RNA 6000 Nano Kit	Agilent Technologies	5067-1511
Bioanalyzer High Sensitivity DNA Analysis	Agilent Technologies	5067-4626
NEBNext Small RNA Library Prep Set for Illumina (Multiplex Compatible)	New England Biolabs	E7330L
Deposited Data
Small RNA-seq data, miRNA	This paper	See https://www.ncbi.nlm.nih.gov/gap/, phs002016.v1.p1
Software and Algorithms
exceRpt small RNA-seq pipeline for exRNA profiling	Genboree Bioinformatics	http://www.genboree.org/site/