The aim of the study is to explore whether transcutaneous vagus nerve stimulation (tVNS) may be effective in preventing mood swings and depressive symptoms in the postpartum phase, as well as serving as a supplementary intervention in cases where mood symptoms develop. The study will investigate the effects of tVNS intervention during the first 12 weeks postpartum. Pregnant women will be recruited for the study, and the intervention will begin shortly after giving birth. Participants will receive different instructions on how to use the tVNS device. Additional parameters such as physiological functions, chronic stress, hormones, environment, and personality traits will also be assessed.