Changes in the renin‐angiotensin‐aldosterone system in normotensive primigravidae in the four days after normal spontaneous delivery

Abstract

Summary. Plasma renin activity, plasma renin concentration, plasma renin substrate, plasma angiotensin II and plasma aldosterone were measured in 10 true primiparae, normotensive throughout pregnancy, for 4 days after a spontaneous vaginal delivery. The concentration of all the measured variables, except plasma renin substrate, fell steeply over the first 3 days post partum. In four of the 10 patients, all components of the renin‐angiotensin system increased in concentration somewhat thereafter, although not to the levels of the first day post partum. There are multiple potential sources of renin in the fetoplacental unit and it is possible that this‘pregnancy’ renin may be capable of the partial suppression of the maternal renin production during pregnancy. The slight rebound observed in some patients may represent a hunting for re‐establishment of non‐pregnant values.

The effect of saralasin in the chronically cannulated ewe in the early puerperium.

“…Following delivery, concentrations of renin and All fall within about 2 h from their elevated pregnant levels to levels within the normal non-pregnant range (Broughton Pipkin, Oats & Symonds, 1978). This fall is followed by a rise to levels comparable with those seen prior to delivery and non-pregnant concentrations are only reached again at about 4 days post partum (Jadoul, Broughton Pipkin & Lamming, 1982). If the observed associations between systemic blood pressure and plasma All concentration are indeed causal, then at some stage in the puerperium All presumably ceases to play a direct role in the maintenance of normal blood pressure.…”

Increased serum aldosterone in diabetic pregnancy

“…Several studies have reported increased plasma aldosterone levels in pregnancy [1]. Particularly elevated plasma aldosterone levels have been demonstrated in pregnant women with diabetes mellitus [2].…”