The goal of this observational study is to explore the impact of pregnancy depression on infant feeding, and to explore the two-way relationship between postpartum depression and infant feeding. Participants will be asked to finish questionnaires four times (24 weeks of pregnancy to before delivery, 2 month postpartum, 4 month postpartum, 6 month postpartum).

Background: Perinatal depression and infant feeding (breastfeeding and complementary feeding) are important global health issues. The prevalence of perinatal depression is high around the world, and breastfeeding rates in middle- and high-income countries are on a downward trend. Past research has pointed out that perinatal depression is related to infant feeding. However, there is a lack of research on the impact of maternal depression on infant feeding in Asian Chinese pregnant women, and "whether there is a bidirectional causal relationship between postpartum depression and infant feeding" remains unclear.

Purpose: To explore the impact of pregnancy depression on infant feeding, and to explore the two-way relationship between postpartum depression and infant feeding.

Method: This is a longitudinal cohort study. It's estimated to recruit 500 pregnant women. It is planned to recruit participants at the Obstetrics and Gynecology Clinic of National Taiwan University Hospital. At the same time, research recruitment advertisements will also be posted online. This study will collect data by questionnaires distributed a total four times (24 weeks of pregnancy to before delivery, 2 month postpartum, 4 month postpartum, 6 month postpartum). Variables include: sociodemographics, maternal variables (parity, number of births, planned pregnancy, maternal complications, mode of delivery, height and weight during pregnancy and postpartum, blood pressure), infant variables (gender, health status , height, weight), anticipatory feeding schedule, health-risk behaviors (smoking and alcohol use), social support, situation of breastfeeding and complementary feeding, reactive feeding, sleep, fatigue, exercise habits, and tendency to depression.

Inclusion Criteria:

• Primipara
• Adult women over 18 years old
• Those with no recurrent pregnancy loss and stable signs of pregnancy
• Those who agree to participate in this study

Exclusion Criteria:

• No exclusion conditions

The participants of this study are pregnant women because this study aims to explore the impact of pregnancy depression on infant feeding, and to explore the two-way relationship between postpartum depression and infant feeding.

It is planned to recruit participants at the Obstetrics and Gynecology Clinic of National Taiwan University Hospital. At the same time, research recruitment advertisements will also be posted online.