The Role of Lactoferrin in Modulating Inflammation and Preventing Preterm Birth: A Narrative Review

Background: Preterm birth (PTB) remains a leading cause of neonatal morbidity and mortality worldwide. Inflammatory cytokines, particularly IL-6, are central to PTB pathogenesis. Lactoferrin (LF), an iron-binding glycoprotein with antimicrobial and immunomodulatory properties, has been proposed as a potential protective factor against PTB. This narrative review aimed to synthesize current evidence on LF supplementation and its effects on inflammation, cytokine modulation, biochemical markers, and obstetric outcomes related to PTB. Methods: Eight clinical studies involving pregnant women at risk of PTB were included. LF was administered orally, vaginally, or through combined regimens, with variations in dosage and duration. Reported outcomes encompassed inflammatory markers, cervical and uterine parameters, oxidative stress biomarkers, and obstetric or neonatal endpoints. Results: Across the studies, LF supplementation was consistently associated with reduced pro-inflammatory cytokines, improvements in cervical length and uterine activity, and favorable changes in oxidative stress markers. Clinically, supplementation was linked with prolonged gestation, fewer preterm births, and reduced neonatal intensive care admissions. Immunological analyses further suggested a positive modulation of cytokine profiles in amniotic fluid. Conclusions: LF appears to exert multifaceted immunomodulatory effects that mitigate inflammation and support pregnancy maintenance. Although findings point to its potential role in PTB prevention, they should be interpreted with caution given the limited and heterogeneous evidence. Further large-scale, multicenter randomized trials are needed to confirm efficacy and to establish optimal dosage, route, and timing of administration.