Urinary prostaglandin excretion in pregnancy: the effect of dietary sodium restriction

Introduction: Dietary sodium restriction results in activation of the renin-angiotensin-aldosterone-system. In the non-pregnant situation renin release in response to a low sodium diet is mediated by prostaglandins. We studied the effect of dietary sodium restriction on urinary prostaglandin metabolism in pregnancy. Patients and methods: In a randomized, longitudinal study the excretion of urinary metabolites of prostacyclin (6-keto-PGF1 αand 2,3-dinor-6-keto-PGF1 α) and thromboxane A2(TxB2and 2,3-dinor-TxB2) was determined throughout pregnancy and post partum in 12 women on a low sodium diet and in 12 controls. Results: In pregnancy the excretion of all urinary prostaglandins is increased. The 6-keto-PGF1 α/ TxB2-ratio as well as the 2,3-dinor-6-keto-PGF1α/ 2,3-dinor-TxB2-ratio did not significantly change in pregnancy. Conclusion:Prostacyclin and thromboxane do not seem to play an important role in sodium balance during pregnancy.