Peripheral serum levels of unconjugated (E1) and total (tE1) oestrone, unconjugated oestradiol-17 beta, unconjugated (E3) and total (tE3) oestriol, progesterone, unconjugated dehydroepiandrosterone (DHA) and dehydroepiandrosterone sulphate (DHAS), and urinary tE3 excretion were determined in pre-eclamptic patients at gestational weeks 32 and 36 and in women with normal pregnancy at the corresponding length of gestation. DHA and DHAS were also analyzed in samples taken 6 weeks after delivery. There were no differences between pre-eclamptic and normal subjects in unconjugated oestrogens and progesterone. Serum tE1 and tE3 levels and urinary tE3 were significantly lower, and the E1/tE1 and E3/tE3 ratios significantly higher in the pre-eclampsia patients. Serum DNA and the DHA/DHAS ratio were significantly elevated in the pre-eclampsia patients during pregnancy, while no differences in these respects were found in the samples taken 6 weeks after delivery. There were no differences in serum DHAS levels. The findings are thought to reflect a general decrease in fetoplacental oestrogen production in combination with a reduced hepatic steroid conjugation in pre-eclamptic subjects.