PURPOSE: This study aimed to compare the neonatal outcome by quantifying the effect of maternal age on low birth weight (LBW). METHODS: We reviewed the medical records of 12,742 newborn infants born at CHA Bundang Medical Center from January 2009 to December 2013. Infants were compared after being categorized by the following 4 maternal age groups - <25 years (N=343), 25-34 years (N=8,573), 35-39 years (N=3,186), > or =40 years (N=640). Statistical analysis included use of logistic regression models with likelihood ratio tests for interaction effects. RESULTS: Incidence of perinatal complications tended to increase significantly with maternal age - gestational diabetes mellitus (GDM; P<0.001), pregnancy induced hypertension (PIH; P=0.019), placenta previa (P<0.001), and cesarean section (P<0.001). Compared to the age group of 25-34 years (reference group), no significant differences were found in age group of 35-39 year [odds ratio (OR)=0.945, 95% confidence interval (CI) 0.847-1.056, P=0.319] and > or =40 years (OR=0.841, 95% CI 0.671-1.056, P=0.136) for LBW. After adjusted by gestational age, incidence of in vitro fertilization (IVF), and perinatal complications, maternal age was not found to be an independent risk factor for LBW (OR=0.847, 95% CI 0.730-0.982, P=0.028 for 35-39 years, and OR=0.652, 95% CI 0.481-0.884, P=0.006 for > or =40 years). CONCLUSION: Although incidence of perinatal complications tends to increase with age, neonatal outcome of age group of > or =35 years measured by incidence of LBW infants was not unfavorable compared to the reference group. The result suggests that the thorough prenatal care may be more important than the maternal age itself.
Cesarean Section ; Diabetes, Gestational ; Female ; Fertilization in Vitro ; Gestational Age ; Humans ; Hypertension, Pregnancy-Induced ; Incidence ; Infant ; Infant, Low Birth Weight ; Infant, Newborn* ; Logistic Models ; Maternal Age* ; Medical Records ; Parturition* ; Placenta Previa ; Pregnancy ; Prenatal Care ; Risk Factors