Pregnancy is characterized by physiological changes in the female body. One of the most reported complaints in the first trimester of pregnancy is nausea and vomiting, with a prevalence that can reach nearly 90% of women [1]. These symptoms can adversely affect the health of pregnant women and their infants, with mental health effects comparable to those of women diagnosed with postpartum depression [2]. In addition to the pregnant woman, the baby is exposed to risks associated with mild to moderate nausea and vomiting, such as an increased risk of low birth weight [3]. A prospective cohort of 2229 pregnant women found an association between nausea and vomiting during pregnancy and an increased risk of low birth weight [3]. In addition, low birth weight is one of the major risk factors associated with neonatal and postneonatal mortality [4].

Acupuncture is one of the complementary integrative practices to control nausea and vomiting. Auriculotherapy is emerging as a modality of acupuncture widely used to relieve various health problems, including anxiety during labor, chronic pain and chemotherapy-induced nausea and vomiting [[5], [6], [7], [8]].

Several studies have investigated the effects of auriculotherapy on nausea and vomiting in pregnant women [[9], [10], [11], [12]]. A comprehensive literature search identified thirteen studies with a total of 1026 participants. Regarding nausea and vomiting of pregnancy (NVP), a subtle but statistically significant difference was observed between the two groups. The systematic review found that the efficacy of auricular acupressure in the treatment of NVP is considered insufficient and its effectiveness remains limited [11]. Another review showed that complementary and alternative medicine (CAM) therapies were successful in alleviating NVP. Acupressure demonstrated superiority over conventional medicine in reducing antiemetic use and achieving a higher efficacy rate [12].

Thus, studies published to date have not yielded consistent conclusions regarding the effectiveness of auricular acupressure on nausea and vomiting of pregnancy (NVP) [[9], [10], [11], [12]]. Therefore, there is a need for rigorously designed randomized controlled trials (RCTs) with larger sample sizes to confirm the effects of auriculotherapy in reducing nausea and vomiting in pregnancy [11,12], which is the aim of the present study. Considering the above, the aim of this study was to evaluate the effects of auriculotherapy on nausea and vomiting during the first trimester of pregnancy.