Plant-Based Diet and Pregnancy-Related Disorders: A Narrative Review

Plant-based diets (PBDs), characterized by minimal or no intake of animal-derived foods and increased consumption of vegetables, fruits, whole grains, legumes, soy products, nuts, seeds, and plant-based oils, have garnered attention for their health benefits and environmental sustainability. While substantial evidence links PBDs to reduced risk of chronic diseases, their role in pregnancy-related disorders remains underexplored. This narrative review aims to evaluate the impact of PBDs on pregnancy-related disorders, including gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), anemia, and overall maternal and fetal outcomes. Evidence suggests that adherence to PBDs—rich in whole grains, legumes, fruits, and vegetables—is associated with lower risks of GDM and HDP in several observational studies. While some studies report increased risk of low birth weight and anemia, others show no significant differences in maternal or fetal outcomes compared to omnivorous diets. Deficiencies in key nutrients—especially vitamin B12, iron, and omega-3 fatty acids—are a concern in poorly planned PBDs. Adequate supplementation and higher educational status support better pregnancy outcomes. Well-planned PBDs may reduce the risk of certain pregnancy complications and support maternal–fetal health when combined with adequate micronutrient intake. However, the evidence remains heterogeneous, and further high-quality longitudinal and interventional studies are warranted to establish the long-term safety and efficacy of PBDs in pregnancy.