Plasma Atrial Natriuretic Factor in Pregnancy

Abstract

Atrial natriuretic factor is a potent vasoactive peptide which has significant effects on vascular smooth muscle and on kidney function. Plasma atrial natriuretic factor concentration is regulated in part by volume status, which is known to be altered in pregnancy. In a cross-sectional study we have measured plasma atrial natriuretic factor by radioimmunoassay in normal non-pregnant and pregnant women. Plasma concentration of atrial natriuretic factor was 8.3 ± 0.9 pg/ml and 10.6 ± 1.9 pg/ml before and after menstruation in six non-pregnant women. Plasma atrial natriuretic factor progressively increased during normal pregnancy being 12.7 ± 1.4pg/ml (n=13), 19.0 ± 2.3 (n=11), and 22.3 ± 1.4 (n=43) in the first, second and third trimesters of pregnancy.

Atrial natriuretic factor may participate in the physiological regulation of vasomotor tone and changes in renal function that occur during pregnancy.