The influence of maternal opiate use in pregnancy on second trimester biochemical markers for Down syndrome.

OBJECTIVE: The object of this study is to examine the influence of maternal opiate use on the levels of second trimester biochemical markers for Down syndrome. Maternal opiate use is known to be associated with problems of placental origin and it is possible that the secretion of alpha-feto protein (AFP), free-beta human chorionic gonadotrophin (HCG) and unconjugated oestriol (UE) differs from that of a normal population. METHOD: Seventy nine women who used opiates in pregnancy were compared to a control group of seventy nine women who did not use opiates and their adjusted marker levels analysed. RESULTS: The adjusted median MoM in the opiate and control groups respectively were: AFP (1.00 vs 0.94), HCG (0.95 vs 1.04) and UE (0.96 vs 1.02), with no significant difference between these groups. CONCLUSION: This study suggests that the current practice of calculating the risk of Down syndrome from second trimester biochemistry in women using opiate can be performed using data derived from a normal population.