ADM and Hypertension: This study shows for the first time that (1) plasma adrenomedullin and MR-proANP concentrations were higher before the 20th week of pregnancy in women who later developed gestational hypertension, (2) NT-proBNP concentrations did not differ between women with pregnancy-induced hypertension and normal pregnancies, (3) MR-proANP concentrations were highest in patients who developed pre-eclampsia in advanced pregnancy, and (4) there was a correlation between higher plasma adrenomedullin, MR-proANP concentrations before the 20th week of pregnancy, and the risk of preterm birth.