The objective of this study was to measure the physical growth of fetuses and infants in an inner city health district in the north of England and to compare their growth profiles according to mother's country of birth (British Isles or Indian subcontinent). The study was part of the Central Manchester Child Growth Project, a prospective longitudinal study of fetal and postnatal growth and development in a sample from the geographically-defined Central Manchester Health District. Data were collected from the beginning of the second trimester of pregnancy to the age of 2 years. One-hundred seventy-four singleton infants born at term ( > or = 37 weeks) had serial antenatal cephalometry every 3 weeks from the beginning of the second trimester and had serial head, length and weight measurements at birth and at the ages of 6, 13, 26, 52 and 104 weeks. Infants of Indian-born mothers tended to be lighter at birth than those of locally-born mothers, but the difference was not due to lower accumulation of soft tissue. Body length from 6 to 52 weeks in both groups of infants was similar. The major finding was the reduced head size in infants of Indian-born mothers, the difference being significant among boys, evident from mid-pregnancy and persisting postnatally to age 2 years. Reduced fetal growth is associated with the development of cardiovascular disease in adulthood, mortality from ischaemic heart disease being specifically linked with head size at birth. The reduced head size of boys of Indian-born mothers is of interest because male immigrants from the Indian subcontinent who live in England have an increased incidence of non-insulin dependent diabetes and a substantial excess mortality (standardised mortality ratio 313 at ages 20-29) from ischaemic heart disease.