Comparison of three prenatal risk scores in a series of low-risk pregnancies

Three prepartum obstetrical risk-scoring methods (Goodwin, Halliday, Hobel) were retrospectively applied to a consecutive series of 795 singleton pregnancies. The study population was low risk overall, with a perinatal mortality rate of 11 per 1000 and a primary cesarean section rate of 9.7%. The predictive ability of the scores was tested for individual outcomes as well as for a "combined measure" designed to group outcomes of clinical interest. Outcome variables examined included labor arrests, need for augmentation of labor, fetal heartrate abnormalities during labor, selection of or transfer to a more intensive level of care, indicated forceps delivery, cesarean section, resuscitation, Apgar scores, permanent injury, and perinatal deaths. Along with expected differences in sensitivity and specificity, there were differences among the three scores in performance as measured by positive and negative predictive value. Goodwin's system performed somewhat better overall. All three systems performed better in multiparous than in primiparous patients, but primiparas experienced more adverse outcomes.