An evaluation of prenatal ultrasound screening for CTEV: accuracy data from a single NHS University Teaching Hospital

Congenital Talipes Equinovarus (CTEV) is one of the most common congenital limb deformities. We reviewed the records of infants who had received treatment for structural CTEV between 1 January 2007 and 30 November 2012. This was cross-referenced with the prenatal scans of mothers over a corresponding period of time. We investigated the sensitivity, specificity, and positive and negative predictive values of the fetal anomaly scan for the detection of CTEV and explored whether the publication of Fetal Anomaly Screening Programme guidelines in 2010 affected the rate of detection. During the study period there were 95 532 prenatal scans and 34 373 live births at our hospital. A total of 37 fetuses with findings suggestive of CTEV were included in the study, of whom 30 were found to have structural CTEV at birth. The sensitivity of screening for CTEV was 71.4% and the positive predictive value was 81.1%. The negative predictive value and specificity were more than 99.5%. There was no significant difference between the rates of detection before and after publication of the guidelines (p = 0.5). We conclude that a prenatal fetal anomaly ultrasound screening diagnosis of CTEV has a good positive predictive value enabling prenatal counselling. The change in screening guidance has not affected the proportion of missed cases. This information will aid counselling parents about the effectiveness and accuracy of prenatal ultrasound in diagnosing CTEV.