Background: The timely initiation of lactogenesis II is crucial for postpartum women, with delays having significant clinical implications. This study aimed to evaluate the determinants of delayed lactogenesis II (DOL II) in high-risk pregnant women to guide clinical interventions and postnatal care protocols. Methods: We conducted a study involving high-risk pregnant women who gave birth and were admitted to our hospital’'s obstetric intensive care unit for postpartum surveillance and treatment from February 1, 2023, to April 30, 2024. We utilized Pearson correlation analysis and logistic regression to determine factors linked to DOL II. Results: Our study included 206 high-risk pregnant women, with 85 (41.26%) experiencing DOL II. Pearson correlation analysis indicated strong associations between DOL II and maternal age (r = 0.452), gestational hypertension (r = 0.514), gestational diabetes (r = 0.487), and delayed colostrum secretion (r = 0.506), all statistically significant ( p < 0.05). Logistic regression analysis identified age 35 years or older (OR = 2.115, 95%CI: 1.785–2.466), gestational hypertension (OR = 2.404, 95%CI: 2.125–3.107), gestational diabetes (OR = 2.556, 95%CI: 2.008–2.879), and colostrum secretion later than one hour postpartum (OR = 3.126, 95%CI: 2.682–3.605) as independent risk factors for DOL II, all with p < 0.05. Conclusions: The incidence of DOL II is significantly elevated in high-risk pregnant women, especially those aged 35 or older, those with gestational diabetes and hypertension, and those who delay the initiation of breastfeeding. It is imperative that clinical practices prioritize enhanced prenatal care and health education, robust lactation support, and improved lactation awareness among postpartum women to reduce the prevalence of DOL II.
