Patrick Christopher Steptoe was born on 9 June 1913, the son of Harry Arthur Steptoe and Grace Maud (née Minns). He was educated at Witney Grammar School, as a medical student at King's College London, and St George's Hospital Medical School (qualified as Member of the Royal Colleges of Surgeons, Licentiate of the Royal College of Physicians in 1939). In 1943 he married Sheena Macleod Kennedy, and they had two children (one son and one daughter).

During the Second World War Steptoe served in the Royal Naval Volunteer Reserve (1939-46) and was a Prisoner of War in Italy (1941–43). Steptoe then went on to be Chief Assistant Obstetrician and Gynaecologist at St George’s Hospital (1947-49); Senior Registrar at Whittington Hospitals in north London (1949); and Senior Obstetrician and Gynaecologist, Oldham Hospitals (1951–78).

Steptoe became a pioneer of laparoscopy (key-hole surgery used to insert a camera through the naval to inspect the uterus) for diagnosis and use in surgery. It was this work which caught the attention of Robert Edwards, and they began their collaboration in 1968.

Alongside Robert Edwards and Jean Purdy, Steptoe carried out clinical research (from 1968) which led to the first success of in vitro fertilisation to treat infertility in 1978 (the birth of the first IVF baby, Louise Brown). The three established Bourn Hall Clinic in Cambridgeshire in 1980, where Steptoe was Medical Director until his death in 1988.

Steptoe was elected Fellow of the Royal College of Obstetricians and Gynaecologists in 1961; made an honorary Doctor of Science of Hull University in 1983; was the first gynaecologist to be elected as a Fellow of the Royal Society in 1987; and was given a CBE in 1988. Steptoe was a founder and first chairman of the British Fertility Society (1973-86) and then President of the Society; he was also President of the International Federation of Fertility Societies (1977-80).

Publications include: 'Laparoscopy in Gynaecology', 1967; 'Progress in Fertility', 1976; contributor to 'Recent Advances in Obstetrics and Gynaecology', 1977; 'A Matter of Life' (with Robert Edwards), 1980; and 'Implantation of the Human Embryo' (with Robert Edwards and Jean Purdy), 1985.