Bengt Källén, MD, PhD, is professor emeritus of the Tornblad Institute at Lund University in Lund, Sweden. Dr. Källén has been professor in embryology since 1965, was head of the Tornblad Institute from 1965-2017, and served as a consultant at the National Board of Health and Welfare in Stockholm from 1964-2015. He has published about 400 scientific articles, many of which concern drug use during pregnancy, and a number of books.