A 35 year old woman at 35 weeks gestation intentionally overdoses on aspirin 325 mg tablets. Maternal aspirin level is 60 mg/dL. How are fetal versus maternal salicylate levels different?
Though limited case reports, there are a few case reports of acute salicylate poisoning in pregnancy. Farid H et al. describe fetal salicylate concentrations 1.5 times higher than maternal concentrations. Additionally, neonates eliminate salicylates more slowly because of immature glucuronidation and renal excretion. Salicylates concentrates in the fetal brain due to a smaller intravascular/intracellular pH gradient.
1. Farid H et al. A 19 year old at 37 weeks gestation with an acute acetylsalicylic acid overdose. NDT Plus 2011; 4(6): 394-396. doi: 10.1093/ndtplus/sfr104.
2. Palatnick W et al. Aspirin poisoning during pregnancy: increased fetal sensitivity. Am J Perinatol 1998; 15: 39-41.
3. Garrettson LK et al. Fetal acquisition and neonatal elimination of a large amount of salicylate. Clin Pharmacol 1975; 17: 98-103.