She worked closely with Robert Gwyn Macfarlane at the Radcliffe Infirmary and Churchill Hospital in Oxford, where she studied coagulation disorders, particularly haemophilia.
[2] In 1944, after holding junior posts in London hospitals, Biggs moved to Oxford, where she joined the Radcliffe Infirmary's pathology department as a graduate assistant.
She initially studied crush syndrome and the variability in haematological tests, under the mentorship of Robert Gwyn Macfarlane.
[2] Biggs and Macfarlane published the textbook Human Blood Coagulation and its Disorders in 1953 and wrote the first UK guidelines for treating haemophilia in 1955.
[4] The Oxford Haemophilia Centre was opened in 1968 at the Churchill Hospital, and it was directed by Biggs from its foundation until her retirement in 1977.