Small foetuses are defined as those with an ultrasound estimated weight below 10th centile. True foetal growth restriction
is associated with signs of abnormal foetoplacental function and poor perinatal outcomes. Constitutionally smallfor-
gestational-age foetuses have nearly normal perinatal outcomes. The differentiation could be made by the umbilical
artery, middle cerebral artery and uterine Doppler measurement and the calculation of cerebroplacental ratio. Low
birth weight, a marker of poor foetal growth, and nutrition is linked to coronary arterial disease, hypertension, obesity
and insulin resistance. Clues originally arose from large 20th century, European birth registries. Professor David Baker
first popularised the concept of foetal origins of adult diseases. Today various animal models and large, diverse human
cohorts confirmed these original observations.