Dornan attended Bangor Grammar School and from there went on to study medicine at Queen's University Belfast where he was mentored by Harith Lamki, Buster Holland and Ken Houston.
On returning to Northern Ireland, he rotated around the north to complete his training and obtain an Honours MD from Queen's in 1981 for his research into Fetal Breathing.
In 1986, he was appointed a consultant Senior Lecturer and subsequently Reader, before he followed Professor Graham Harley at the Royal Maternity Hospital.
[5] In 2004, Dornan was elected Senior Vice President of the Royal College of Obstetricians and Gynaecologists in London,[6] having been on its Council as a Fellow for the previous five years.
Amongst them was the establishment of an emergency obstetrician that provides lifesaving skills for medics, midwives and nurses in under-resourced countries, while working closely with the Liverpool School of Tropical Medicine.