While at Queen Charlotte's, in co-operation with Professor J. H. Burn, he published research papers on uterine action in labour and in response to various drugs. During the First World War from 1914 to 1917 Bourne enlisted in the British Army and served as a surgical specialist with the 17th General Hospital in Egypt and the 2nd General Hospital in France. After the war, he built a successful consulting practice in obstetrics and gynaecology. In 1929, he was elected a foundation member of the Royal College of Obstetricians and Gynaecologists and, founding its museum in 1938, served as curator of its museum which he built up considerably during the following years. In 1934 he was appointed as Consulting Obstetrical surgeon at St Mary's Hospital.