Premature rupture of membranes (PROM) and cervical incompetence (CI) are major contributors to preterm birth, a leading cause of neonatal morbidity and mortality. Background/Objectives: Disorders of the vaginal microbiota, such as bacterial vaginosis, have been associated with an increased risk of PROM, CI, and subsequent preterm birth. Probiotics, particularly Lactobacillus strains, have been proposed as a preventive strategy to restore and maintain a healthy vaginal microbiome. This review aims to summarize the latest evidence on the role of probiotics in the prevention of PROM and CI. Methods: A comprehensive review was conducted to evaluate the effectiveness of probiotic interventions in the prevention of PROM and CI, yielding 1809 records from 2005 to 2024. Seven relevant studies were selected by searching medical databases and focusing on studies that investigated the restoration of healthy vaginal flora, the reduction of pathogenic bacteria colonization, and the modulation of immune responses by probiotics. Results: The studies analyzed suggest that probiotics may help restore healthy vaginal flora, reduce pathogenic bacterial colonization, and modulate immune responses, thereby reducing the risk of membrane rupture and cervical insufficiency. Evidence from randomized controlled trials and observational studies shows that the use of probiotics is associated with a lower incidence of PROM and preterm birth, especially in high-risk groups. Conclusions: Probiotics emerge as a potential non-invasive and cost-effective strategy to improve pregnancy outcomes in women at risk of preterm birth due to PROM. According to our research, probiotic prophylaxis of cervical insufficiency has not yet been sufficiently investigated. Despite the promising findings, further research is needed to determine standardized probiotic formulations, optimal timing, and routes of administration. Personalized probiotic therapies may represent the future of preterm birth prevention as they offer targeted interventions based on individual microbiome composition.