Steroid profiling in preeclamptic women: evidence for aromatase deficiency

Experimental data have revealed the critical role played by 2-methoxy-estradiol, a metabolite of 17β-estradiol, in the pathophysiology of preeclampsia. We used gas chromatography/mass spectrometry to measure a whole panel of hormonal steroids in the plasma from women during the third trimester of their pregnancy.

The population study consists of 24 pregnant patients with different outcomes: normal, or complicated by isolated preeclampsia or by severe preeclampsia with Hemolysis Enzyme Liver Low Platelets (HELLP) syndrome.

17β-estradiol was reduced by 50% in isolated preeclampsia, and by 70% in severe preeclampsia with HELLP syndrome (normal: 8.54 ± 0.9 ng/mL; isolated preeclampsia: 4.65 ± 1.0 ng/mL; severe preeclampsia with HELLP syndrome: 2.64 ± 0.4 ng/mL), as is estrone. Downstream, 2-methoxy-estradiol was decreased only in severe preeclampsia with HELLP syndrome. The concentrations of estrone and 17β-estradiol precursors were comparable between groups, suggesting that placental aromatase is deficient in preeclampsia.

The gradual decrease of estrogen levels with increasing severity of preeclampsia suggests an impairment of placental steroidogenesis.