A reappraisal of urinary oestriol excretion as a screening test in pregnancy.

During the years 1971-1982 urinary oestriol excretion was tested in 38,536 patients (group 1). One or more low oestriol value was found in 11.0% of patients; in this group the stillbirth rate was 8 times higher, the neonatal death rate 4 times higher, and fetal growth retardation rate 4 times higher than in patients with normal oestriol values (all p less than 0.001). During the years 1982-1984 a further 12,887 patients were tested (group 2) and 9.5% had one or more low oestriol value. The perinatal mortality rate in patients with normal oestriol excretion fell from 0.8% in group 1 to 0.5% in group 2 (p less than 0.05), and in patients with low oestriol excretion from 4.7% in group 1 to 2.4% in group 2 (p less than 0.01). However, patients in group 2 with low oestriol values still had significantly unfavourable results, compared to those with normal oestriol values--stillbirth rate 4 times higher, neonatal death rate 5 times higher, and fetal growth retardation rate 4 times higher (all p less than 0.001). Although perinatal results have improved, fetal growth retardation and the risk of perinatal death are still identified by urinary oestriol assay.