The predictive value of a normal ultrasound scan in the preterm baby--a meta-analysis

Interpretation of the prognostic value of cranial ultrasound abnormalities in preterm infants has been hampered by the lack of a uniform approach to research, especially in the definition and classification of the abnormal appearances. Defining normality should be less controversial, but from a selected reading of the literature it is possible to gain quite varied impressions as to the prognostic value of normal ultrasound appearances. In order to determine the predictive value for normal development of consistently normal cranial ultrasound scans in the preterm baby, we have performed a meta-analysis on all the published reports in the English language which provide follow-up data on such cases. The overall prevalence of major disability among 1,604, mainly very low birthweight, babies was 15%. The predictive value of a normal scan for freedom from major disability was 93% and the predictive value for an entirely normal outcome was 88%. The value of this information in the counselling of parents is discussed.