Abstract: Objective: To investigate the influence of Pre-Pregnancy Body Mass Index (PPBMI) and Gestational Weight Gain (GWG) on the establishment of early breastfeeding behavior, and to identify high-risk groups with difficulty in establishing early breastfeeding behavior. Methods: A total of 364 women were selected in a Nanjing maternity and child health care hospital from March 2020 to July 2020 by convenience sampling. The breastfeeding process at the first postpartum few days was observed. The breastfeeding process indicators (including latching and sucking, breastfeeding frequency, breastfeeding preparation time, and single breastfeeding duration) and rate of early breastfeeding were compared. Results: After adjusting confounding factors, compared with women with normal-weight and adequate GWG, maternal underweight increased the risk of latch difficulty (OR=2.025, P=0.044), and low-frequency feeding (OR=2.057, P=0.021). Overweight (OR=0.392, P=0.015) and excessive GWG (OR=0.538, P=0.021) reduced the rate of early exclusive breastfeeding. Conclusion: Women who were underweight or overweight before pregnancy and excessive GWG were at high risk for establishing early breastfeeding behavior. Therefore, it is necessary to comprehensively implement weight management and pregnancy weight gain counseling in women of childbearing age. At the same time, health care professionals should provide targeted breastfeeding support to high-risk groups to improve breastfeeding status.

Key words: Pre-Pregnancy Body Mass Index; Gestational Weight Gain; breastfeeding; breastfeeding behavior