 Shapiro and Zwarenstein's letter published in the "British Medical Journal" on 16 November 1946 clarified that Hogben was retrospectively wrongly claiming credit for discovering the pregnancy test.Nobel laureate John B. Gurdon of the Wellcome CRC Institute and Nick Hopwood of the Department of History and Philosophy of Science, University of Cambridge, elaborated on this in detail in their comprehensive article published in "The International Journal of Developmental Biology", pointing out that although Hogben had demonstrated in principle that Xenopus might be used for testing the presence of gonadotrophins in a pregnant woman's urine, his reporting had not mentioned pregnancy testing at all; he seemed to have had other research directions.While Chair for Social Biology at the London School of Economics, Hogben unleashed a relentless attack on the British eugenics movement, which was at its apex in the 1920s and 1930s.