Associate Professor Andrew McLennan is a specialist obstetrician and gynaecologist whose particular interest is in prenatal diagnosis and ultrasound. He is a consultant to the Maternal Fetal Medicine Unit at Royal North Shore Hospital, a Clinical Associate Professor at the University of Sydney and a Sonologist at Sydney Ultrasound for Women. In a national first, Andrew introduced Nuchal Translucency (NT) screening for Down syndrome to Australia, helping to revolutionize the way prenatal screening for chromosome abnormality is conducted. He is the founding Chairman of the National Early Pregnancy Assessment Program and the past President of the Australian Association of O&G Ultrasonologists. Andrew has been involved in educating doctors and sonographers in Australia and South-East Asia in the conduct of early pregnancy screening for fetal chromosome abnormalities and adverse pregnancy outcomes. He is actively involved in research into early diagnosis of fetal abnormalities and quality assurance in ultrasound.