Source:
http://www.uua.org/sites/live-new.uua.org/files/documents/ncadv/dv_pregnancy.pdf
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3349286/
https://aapcc.s3.amazonaws.com/pdfs/annual_reports/2011_NPDS_Annual_Report_-_Final.pdf
http://www.ncbi.nlm.nih.gov/pubmed/12907100
