He graduated from the University of Queensland with a medical degree in 1991. Following speciality training in obstetrics and gynaecology, Dr Gardener went on to sub-specialise in maternal fetal medicine, working at King George V Hospital in Sydney and University College Hospital in London. Dr Gardener returned to Mater in 2003 as a consultant in Maternal Fetal Medicine, becoming Director of the Mater Centre for Maternal Fetal Medicine in 2009.
Dr Gardener has a long held interest in fetal therapy including in-utero surgery and is currently the only specialist in Australia and New Zealand performing fetal surgery for diaphragmatic hernia and spina bifida. He regularly performs surgery for twin-to-twin transfusion syndrome, in-utero blood transfusions and other complex in-utero procedures.
With a particular interest in the prevention of stillbirth, Dr Gardener is involved in research and is a current board member for the International Stillbirth Alliance and leads a Fetal Therapy Special Interest Group through the Perinatal Society of Australia and New Zealand (PSANZ).
Dr Gardener is actively involved in teaching obstetric ultrasound and passing on his skills to new doctors.