The outcome of five years' implementation of maternal serum screening for Down's syndrome comparing actual age risks and mode of delivery

Abstract

In this paper 13 613 triple test results from the period 1992- 1997 were analysed. The probability of receiving a high risk result for Down's syndrome from a serum screen, related to the patient's age, was calculated. The modes of delivery of the patients receiving a high risk result were also compared with the rest of the population. The probability of receiving a high risk result increased from 1.2% at 25 years of age to 43.9% at 40 years of age. There was a decrease in the likelihood of having operative intervention at delivery amongst the high risk group but this did not reach statistical significance. This highlights the need for accurate information in risk and probability when counselling a patient undergoing serum screening. Patient's anxiety relating to mode of delivery may also be alleviated by knowing they have no greater risk of operative delivery.