Pregnancy is intrinsically imperfect, with high rates of complications for mothers and babies. A minority of pregnancies is entirely uncomplicated. Medical disorders are frequent contributors to morbidity for mothers and babies, and have become the major source of maternal mortality. For these reasons, Medicine plays a central role in the care of pregnant women. Provision of resources to maternity services must recognise the changing demographics and clinical characteristics of pregnant women in Australia, and their increased medical risk status in recent years.