Atrial natriuretic peptide concentrations in umbilical cord plasma from pre‐eclamptic women

Atrial natriuretic peptide (ANP) was measured in arterial and venous umbilical cord plasma at the time of delivery by cesarean section in pre-eclamptic (n = 7) and normal women (n = 6). In addition venous samples were obtained from pre-eclamptic (n = 7) and normal pregnant women (n = 7) near term. ANP plasma levels were higher in pregnant women with pre-eclampsia than in normal pregnant women (27.9 +/- 4.4 [mean +/- SEM] and 14.1 +/- 2.5 pmol l-1, respectively, P less than 0.05). Immediately after delivery plasma ANP in pre-eclamptic mothers was 66.7 +/- 12.8 pmol l-1 compared to 13.9 +/- 2.2 pmol l-1 in normal mothers (P less than 0.01). However, in the pre-eclamptic group the levels of ANP in arterial and venous umbilical cord plasma (19.5 +/- 4.2 and 16.7 +/- 4.3 pmol l-1, respectively) were significantly (P less than 0.01) lower than ANP levels in arterial and venous cord plasma (39.6 +/- 1.0 and 31.1 +/- 4.2 pmol l-1, respectively) from normal mothers. It is concluded that the increased ANP plasma level in pre-eclamptic women originates from a maternal source. In addition, since the ANP level is lower in cord plasma than in maternal plasma in pre-eclampsia, feto-placental volume homeostasis may also be changed in pre-eclampsia.