Objective  To explore the prevalence and influencing factors of depression among first-time pregnant women during middle and late gestation and to provide evidences for mental health promotion of the women.

  Methods  We conducted an on-site self-administered survey among 990 first-time pregnant women accessing prenatal examination at a hospital in a city in Northern Jiangsu province during their second or third trimester between July and December 2017. A general questionnaire was used to collect demographics, health status, disease history, and other relevant information; Beck Depression Inventory (BDI) was adopted to assess depression of the women. Epi Data 3.3 and SPSS 19.0 statistical software were used in data double-entry and analysis.

  Results  The overall detection rate of depression symptoms was 78.5% among the respondents and the rate of mild, moderate, and major depression were 19.2%, 47.9%, and 11.4%, respectively. Univariate analysis resulted in following influencing factors of depression: occupation (F = 2.366, P = 0.021), hair perming or dyeing (F = 3.682, P = 0.012), wearing tights (F = 3.911, P = 0.009), wearing high heels (F = 3.182, P = 0.023), carrying a cellphone close to the body (F = 3.353, P = 0.018), turning a cellphone on before sleep and putting it near the bed (F = 2.939, P = 0.032), knowledge about sexuality (F = 3.374, P = 0.035), the age at first sex (F = 2.805, P = 0.039), times of vulva washing per week (F = 17.486, P = 0.000), dyspareunia (F = 2.852, P = 0.036), trouble falling asleep (F = 8.003, P = 0.000), occupational exposure to high temperature (F = 3.725, P = 0.011), exposure to pesticides or insecticides (F = 4.109, P = 0.007), fried food consumption (F = 5.444, P = 0.001), smoked food consumption (F = 3.339, P = 0.019), consumption of food containing additives (F = 3.504, P = 0.015), conjugal relationship (F = 3.254, P = 0.021), relationship with mother-in-law (F = 5.685, P = 0.001), relationship with parents (F = 4.138, P = 0.006), relationship with friends (F = 4.818, P = 0.002), and mental stress in daily life or work (F = 11.718, P = 0.000). Logistic regression analysis revealed that dyspareunia, wearing tights, carrying a cellphone close to the body, trouble falling asleep, consumption of food containing additives such as instant noodle, exposure to pesticides or insecticides, and mental stress in daily life or work were main risk factors for depression among the respondents.

  Conclusion  Changing unhealthy living habits, improving poor working environment, promoting interpersonal skill and coping with various life events appropriately are important measures for depression prevention among pregnant women during middle and late pregnancy.