RESEARCH ARTICLE Toxicology and teratology

is available at the end of the articleBackground The rates of muscle aches, sprains, and inflammation are significantly increased during pregnancy, often resulting in lower back and neck pain [1]. These pain symptoms tend to increase as pregnancy advances through the first, sec-ond, and third trimesters [1-4]. It has been estimated that approximately two-thirds of pregnant women in the United States experience lower back pain, and more than 50 % of them receive little or no treatment from their phy-sicians [4,5]. This could be attributed to the fears of fetal risks associated with the use of systemically administered agents such as non-steroidal anti-inflammatory drugs. Therefore, the use of topical analgesics seems attractive for women afraid of adverse effects of oral medications. Among topical analgesics, the Professional Therapy MuscleCare (PTMC) has been shown to be effective in alleviating muscle pain in a randomized, placebo-controlled double-blind study of five topical analgesics [6]. The line of PTMC products includes an ointmen