Genetic risk is a primary contributing factor to the predisposition of a newborn child to elevated blood pressure later in life. An index of this factor is needed to assess in the neonate the success or failure of preventive interventions instituted for the pregnant women. This index could be based on characteristics of blood pressure and heart rate variability measured during the first 2 days after birth. In the search for such an index, the systolic and diastolic blood pressures and heart rates of 127 newborn babies were automatically monitored at about 30-min intervals for 48 h with a Nippon Colin device, starting early after birth. Circadian parameters (obtained by the linear least-squares fit of a 24-h cosine curve to each individual series) and descriptive statistics for the three circulatory variables were used in a multiple regression analysis to compute a linear prediction function for the cardiovascular risk score. This score was obtained for each neonate on the basis of the presence or absence of overt cardiovascular disease, elevated blood pressure, or obesity across two generations, those of the newborn's parents and grandparents. Results from regression indicate that the best model includes the circadian amplitudes of systolic and diastolic blood pressure and the circadian ranges of systolic blood pressure and heart rate. The contributions from patroclinous versus matroclinous family history were then compared. Results show that linear prediction models include the same variables for both paternal and maternal cardiovascular risk score. These results provide a neonatal index of cardiovascular risk, to be used later for the evaluation of the effects on the newborn of intervention for the pregnant women.