Study of the effect of low-dose aspirin in pregnancy on maternal and neonatal aspirin concentrations

ABSTRACT

The objective of this study is to evaluate maternal and neonatal plasma concentrations of acetylsalicylic acid and salicylic acid and the neonatal endogenous prostanoid formation during Iow-dose aspirin prophylaxis [LDA; 75 mg daily] in pregnant women. Concentrations of acetylsalicylic acid and salicylic acid in maternal plasma after at least 4 weeks of LDA [n = 14] and in umbilical cord plasma of newborns after maternal LDA [n = 7] were determined by gas chromatography-mass spectrometry. Platelet and renal formation of thromboxane A2 and the formation of prostaglandin E2 and prostacyclin were evaluated in vivo by quantification of index metabolites in plasma and urine by gas chromatographymass spectrometry in neonates after maternal LDA [n = 14] and in a control group. The results proved that in the pregnant women, acetylsalicylic acid and salicylic acid concentrations rapidly increased after ingestion of LDA. Acetylsalicylic acid was completely eliminated within 4 hours, whereas salicylic acid was detected with low concentrations at 18 and 21 hours after dosing. In the neonates, acetylsalicylic acid was not detected. Salicylic acid was detected in 1 infant only. Platelet thromboxane A2 formation in the newborn infants was significantly suppressed but recovered within 2 to 3 days after discontinuation of LDA. Renal thromboxane A2 formation and the formation of prostaglandin E2 and prostacyclin were not affected by LDA