Changes of circulating atrial natriuretic peptide at vaginal delivery in women with essential hypertension

To examine the influence of vaginal delivery in hypertensive pregnancy on atrial natriuretic peptide [ANP], its concentrations were determined by radioimmunoassay technique in 30 pregnant women with established essential hypertension and 10 comparable healthy pregnant controls, during late pregnancy, labor and immediately after vaginal delivery. Plasma ANP levels were increased from 198.96 +/- 16.9 pg/ml during late pregnancy to 228.28 +/- 20 pg/ml during labor and 276.97 +/- 8.7 pg/ml immediately after vaginal delivery in women with essential hypertension. These differences are statistically significant. A positive correlation between ANP and mean arterial pressure is demonstrated