Effectiveness of aromatherapy with sweet orange oil (Citrus sinensis L.) in relieving pain and anxiety during labor

•The EOCs significantly reduces pain during labor;•The EOCs is more effective during the first stages of dilation and in primiparous women;•The anxiety was reduced in pregnant women exposed to aromatherapy with EOCs. Need to improve the quality of vaginal birth in a humanized and non-invasive way, contributing to pain and anxiety during labor. Integrative and complementary practices, such as aromatherapy, have been an important tool for managing natural birth. To evaluate the effects of Citrus sinensis L. aroma on pain and anxiety during labor. Single-blind randomized clinical trial with pregnant women was performed in a city of Brazilian northwest. The pregnant women were divided (n=42/group) into an experimental group (inhalation of 250 μL of C. sinensis essential oil) and a placebo group (250 μL of distilled water), and submitted to the evaluation of pain intensity through Visual Analogic Scale, anxiety (STAI-E), physiological parameters, as well as fetal heart rate. Aromatherapy significantly reduced pain intensity over time (p=0.0411), especially for pregnant women in stage 1 dilatation and primiparous (p=0.0022). In addition, essential oil inhalation also reduced anxiety (p