Effect of Maternal Weight Gain on Neonatal Birth Weight and Pregnancy Outcomes in Normal Pre-pregnancy Body Mass Index

Objective: To compare neonatal birth weight, incidence of large for gestational age (LGA), macrosomia and pregnancy outcomes between excessive and normal maternal weight gain in singleton pregnancies with normal pre-pregnancy body mass index ( BMI). Materials and Methods: A retrospective cohort study of 320 singleton pregnancies was analyzed (160 per group). Labour records of singleton pregnant women with normal pre-pregnancy BMI who delivered at Khon Kaen Hospital between 1 st August and 30 th November 2013 were reviewed. Neonatal birth weight, pregnancy outcomes such as shoulder dystocia, uterine atony and birth trauma between two groups were analyzed. Results: The mean neonatal birth weight in the excessive weight gain group was significantly greater than in the control group (3,295± 468 g and 3,127 ± 375 g, p <0.01). Infants with LGA in excessive weight gain group was significantly more than in control group (22.5% and 12.5%, p= 0.02, adjusted RR= 2.5 (95% CI 1.17-3.98)).The adverse maternal and neonatal outcomes such as shoulder dystocia, neonatal hypoglycemia and birth trauma were not significant different between two groups. Conclusion: Excessive maternal weight gain in pregnant women with normal pre-pregnancy BMI women was associated with neonatal birth weight and influence LGA.