Women receiving acupuncture on the day of embryo transfer (ET) perceive less stress, which may play a role in improving their chances of becoming pregnant. In an observational, prospective, cohort study, American investigators studied 57 infertile patients undergoing IVF or ICSI. Patients underwent ET with or without acupuncture as part of their standard clinical care. 64.7% of women who received acupuncture achieved pregnancy, compared with 42.5% of those who did not have acupuncture. Upon further analysis, in which patients were stratified by donor recipient status, only non-donor recipients showed a potential improvement in pregnancy rates (35.5% without acupuncture vs. 55.6% with acupuncture). The women who received acupuncture reported lower perceived stress scores pre-ET and post-ET than those who did not. Women with decreased perceived stress scores compared to baseline were found to have higher pregnancy rates than those who did not demonstrate this decrease, regardless of acupuncture status. (The relationship between perceived stress, acupuncture, and pregnancy rates among IVF patients: a pilot study. Complement Ther Clin Pract. 2010 Aug;16(3):154-7).