1. Barrow MV, Souder DE. Propoxyphene and congenital malformations. JAMA. 1971;217:1551–2.
2. Broussard CS, Rasmussen S, Reefhuis J, Friedman JM, Jann MW, Riehle-Colarusso T, Honein MA, for The National Birth Defects Prevention Study. Maternal treatment with opioid analgesics and risk for birth defects. Am J Obstet Gynecol. 2011;204(314):21–314.e11.
3. Golden NL, King KC, Sokol RJ. Propoxyphene and acetaminophen. Possible effects on the fetus. Clin Pediatr. 1982;21:752–4.
4. Gouraud A, Beyens MN, Boyer M, Carlier P, Thompson MA, Garayt C, Bernard N, Vial T. First trimester exposure to tramadol: a prospective comparative study. Fundam Clin Pharmacol. 2010;24(Suppl. 1):90.
5. Heinonen OP, Slone D, Shapiro S. Birth defects and drugs in pregnancy. Littleton, MA: Publishing Sciences Group; 1977.