Can the New Zealand antenatal scoring system be applied in the United Kingdom?

Abstract

We aimed to assess the sensitivity and predictive values of using Knox scoring in the United Kingdom, in order to reduce unnecessary hospital referral. One hundred and sixty-six pregnant women were assessed at booking by the current antenatal scoring as well as by Knox scoring and then the same women were reassessed at 36 weeks' gestation. At booking Knox scored 11·7% of women as high risk while the current antenatal system scored 48·9%. At 36 weeks' gestation Knox scored 1·4% of the same pregnant women as high-risk when our scoring system identified 37·9% as high-risk women. We had one case of perinatal death and nine cases of perinatal morbidity. Knox scoring showed a higher positive predictive value (17·6% vs. 12·1%) but less sensitivity (30% vs. 90%) than the current scoring system. That will lead to dramatic reduction of hospital referral at the booking visit from 48·9% to 11·7% and late in pregnancy from 37·9% to 1·4%.