Objective: The aim of this study was to assess whether low maternal MCV values are associated with adverse course of vaginal delivery. Study design: A retrospective analysis of 92 consecutive vertex singleton vaginal deliveries in nulliparous women in a university tertiary health care facility. MCV was considered as major outcome variable. Results: 54.1% of Parturients with higher MCV needed oxytocin augmentation during labor as compared to 79.5% of parturients with lower MCV (P<0.05). The need for oxytocin for augmentation of labor was decreased with larger MCV (OR 0.90 per fL, 95% CI 0.82–0.98, P<0.05). No correlation was found between MCV and other parameters of labor course. Conclusion: Low maternal MCV values were associated with increased use of oxytocin augmentation during vaginal delivery.