13 Apr 1953 Short Service Commission Lieutenant RAMC.
13 Apr 1954 Short Service Commission Captain RAMC.
Malta 1954 Served in Malta. Whitfield said that: "in 1954 I got to Malta and within a few days was doing an exchange transfusion with glass cannulas and bits of metal linked together with rubber tubing, and with just a two-way syringe".1
Malta 1955 Served in Malta.
1955 Junior Specialist in Obstetrics and Gynaecology.
Malta 1 Sept 1956 Birth of a daughter, Catherine May, to Charles Richard and Marion Douglas. The baby was baptised at St Oswald's Church Mtarfa on 4 Nov 1956. The family resided at No 2 St Agatha's Esplanade Mdina.
7 June 1956 Permanent Regular Army Commission Lieutenant RAMC.
Malta 1957 Served in Malta.
1957–1959 On duty at The Louise Margaret Hospital Aldershot.
16 Mar 1959 Major RAMC.
1959 Senior Specialist in Obstetrics and Gynaecology.
1959–1960 Served at the Military Hospital Colchester.
1960–1963 Served at the British Military Hospital Singapore.
16 Mar 1964 Lieutenant Colonel RAMC.
13 Apr 1964 Left the army. Returned to Belfast to take up a post of Senior Lecturer in Obstetrics and Gynaecology at Queen's University.
1968 Consultant in Obstetrics and Gynaecology to the Belfast hospitals.
1974 Appointed Professor of Obstetrics and Gynaecology at the University of Manchester. Held the post until he moved to Glasgow in 1976, where he became Emeritus Regius Professor of Midwifery, The Queen Mother's Maternity Hospital, University of Glasgow until 1992.
Prof Whitfield was a pioneer in fetal medicine. He undertook research in Rhesus incompatibility of the newborn. During the 1970s, he was instrumental in introducing blood transfusions in the womb for babies who developed rhesus disease or haemolytic disease of the newborn.