FETAL ASSESSMENT BASED ON FETAL BIOPHYSICAL PROFILE SCORING VIII - THE INCIDENCE OF CEREBRAL-PALSY IN TESTED AND UNTESTED PERINATES

OBJECTIVE: The intent of this comparative clinical study was fourfold: (1) to determine the incidence of cerebral palsy in a large obstetric population, (2) to compare the incidence of cerebral palsy in patient s at high risk referred for and managed according to the fetal biophys ical profile score result with the incidence among unreferred and unte sted patients, (3) to determine the relationship, ii any, between the last fetal biophysical profile score and the incidence of cerebral pal sy, and (4) to categorize cases of cerebral palsy according to the cli nical parameters and the probable time and nature of the damaging insu lt. STUDY DESIGN: In this retrospective 5-year comparative study (1987 to 1991) the incidence of cerebral palsy was determined by analysis o f International Classification of Diseases, Ninth Revision, -coded rel ated medical services. The clinical records were then sought and revie wed in index cases and obstetric, neonatal, and postnatal clinical dat a were abstracted. Cross-correlation with partial registries was done to confirm completeness of capture of index cases. The population of r eferred high-risk patients who received serial fetal biophysical profi le scoring and were managed according to test results was determined b y review of a prospective computer-stored database and by review of pa tient log books. The population of untested patients was calculated as the residual of total cases minus tested cases. The rate of cerebral palsy for all patients and for the tested and untested population was calculated acid compared. The tested and untested perinates were compa red for birth age, weight, and assigned timing or etiology of cerebral palsy. In the tested population the distribution of test results by l ast recorded biophysical profile score was determined and the relation ship between the last test result and cerebral palsy and predictive ac curacy parameters of the fetal biophysical profile score were calculat ed. RESULTS: The incidence of cerebral palsy among the 84,947 live bir ths was 3.68 per 1000 live births (313 cases). The rate of cerebral pa lsy in the 26,290 referred high-risk tested patients was 1.33 per 1000 (35 cases) compared with a rate of 4.74 per 1000 live births in the 5 8,657 untested mixed low-risk/high-risk patients (278 cases). These di fferences were highly significant. A significant declining trend in th e annual incidence of cerebral palsy was observed in the total populat ion and the untested population, whereas the rate in the tested popula tion remained relatively constant over the 5-year study interval. The differences in the cerebral palsy rate between the tested and untested population were not related to differences in gestational age, birth weight, or assigned timing or etiology category. In the tested populat ion the relationship between the incidence of cerebral palsy and the l ast test fetal biophysical profile score was inverse, exponential, and highly significant. CONCLUSIONS: Antepartum assessment by fetal bioph ysical profile scoring is associated with a significant reduction in t he incidence of cerebral palsy compared with untested patients. The re lationship between the last test score and the incidence of cerebral p alsy is inverse and exponential, suggesting that antenatal asphyxia is an important and potentially avoidable cause of cerebral palsy.