EVALUATION OF A FETAL RISK-SCORING SYSTEM

A population of 2029 pregnant women (929 primiparas; 1100 multiparas) has been used to examine aspects of the calculation of obstetric risk scores from the presence of individual risk factors. The findings have been related to fetal outcome in these pregnancies and the following conclusions were reached: (1) the use of Bayes theorem for the calculation of a risk score is superior to the simple addition of weighted risk factors; (2) the diagnostic efficiency of a risk score is somewhat reduced when the data base used for calculation of the score is derived from a population different from that of the current pregnancy; (3) there is almost total overlap of risk scores in women with satisfactory and unsatisfactory fetal outcome. It is concluded that risk scores can be used to identify a small group of women at particularly high risk; in the remainder of the population scores are unhelpful except perhaps to indicate the women who do not require an intensive program of antenatal care.