SMOCC : Design of a representative cohort-study of live-born infants in the Netherlands

The Social Medical Survey of Children attending Child Health Clinics (SMOCC) was initiated to obtain reference data on morbidity in children in their first two years of life. During 1988 and 1989, the staff of 21 Child Health Clinics recorded data on the pre- and perinatal period, and on the first two years of life, of infants born in the geographically defined catchment areas of these clinics. The cohort is representative of the newborn population of the Netherlands with respect to mother's age at delivery, parity and, to a somewhat lesser extent the level of maternal education and degree of urbanization of residential area. The incidence of preterm birth and of very preterm birth in the sample was 6.8% and 0.66%, respectively. Incidence of low birthweight and of very low birthweight was 6.0% and 0.71%, respectively. Birthweights of singleton infants were in accordance with the national standard (the Amsterdam intrauterine growth charts)