Objective: This study evaluates the effects of medical nutrition guidance provided to pregnant women to reduce pregnancy complications and occurrence of low birth-weight children and macrosomia. This guideline aims to provide the basis for improving birth delivery outcomes. Materials and Methods: A randomized controlled method was used. A total of 261 parturient women who enrolled in regular pregnancy testing were sampled and selected. The subjects were randomly divided into experimental group (EG, n = 124) and control group (CG, n = 132). The differences in maternal health, pregnancy outcomes, and newborn health between the two groups were compared. Results: Hypertensive disorders in pregnancy and gestational diabetes risks in EG were significantly lower than those in CG (p < 0.05). The cesarean section rate decreased (EG 36.29%, CG 51.50%), and the vaginal delivery rate increased (EG 63.71%, CG 51.50%). The incidence of macrosomia in EG was significantly lower than that in CG (p < 0.05). Conclusion: Medical nutrition guidance during pregnancy improves the perinatal outcomes of mothers and children.