title: Low-dose aspirin in pregnancy: maternal and neonatal aspirin concentrations and neonatal prostanoid formation.
abstract: OBJECTIVE
  To evaluate maternal and neonatal plasma concentrations of acetylsalicylic acid and salicylic acid and the neonatal endogenous prostanoid formation during low-dose aspirin prophylaxis (LDA; 100 mg daily) in pregnant women.
  
  
  METHODS
  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 chromatography-mass spectrometry in neonates after maternal LDA (n = 14) and in a control group.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  In pregnant women who are treated with LDA, acetylsalicylic acid is not completely inactivated in the portal circulation but reaches the uteroplacental circulation and exerts antiplatelet effects in the fetus and newborn.
authors.affiliation: Department of Pediatrics, Philipp's University, Marburg, Germany. andreas.leonhardt@mailer.uni-marburg.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Leonhardt
authors.forename: Stefanie
authors.initials: S
authors.lastname: Bernert
authors.forename: Bernhard
authors.initials: B
authors.lastname: Watzer
authors.forename: Gabriele
authors.initials: G
authors.lastname: Schmitz-Ziegler
authors.forename: Hannsjörg W
authors.initials: HW
authors.lastname: Seyberth
mesh_terms: D001241:Aspirin / Q000008:administration & dosage* / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism; D015232:Dinoprostone / Q000097:blood; D011464:Epoprostenol / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D011225:Pre-Eclampsia / Q000517:prevention & control; D011247:Pregnancy / Q000097:blood* / Q000652:urine; D011453:Prostaglandins / Q000097:blood* / Q000652:urine; D020156:Salicylic Acid / Q000097:blood
chemical_list: D011453:Prostaglandins; D011464:Epoprostenol; D015232:Dinoprostone; D020156:Salicylic Acid; D001241:Aspirin