Maternal Prenatal Anthropometry, High Education and Cesarean Delivery as Risk Factors for Low Gestational Age in Iran

Preterm birth is an important contributor to the global burden of disease. Evidence indicating that maternal health, nutritional and socioeconomic status may contribute to preterm birth. This cross-sectional study was conducted to describe the contribution of prenatal maternal factors on low gestational age, and to assess newborns anthropometric measurements regarding gestational age. Data of mothers delivering a singleton live infant (n= 759) and their newborns (n= 755) during the two years up to August 2014 were collected. Data were collected from the data set of eight public health centers which were chosen from different administrative regions of Tabriz city and were analyzed. Differences between the groups were assessed by Student’s t-test or one- way analysis of variance (ANOVA). Multiple linear regression was used to estimate the association between gestational age and variables studied. Incidence of preterm birth was 2.1%. Percentage of infants with low birth weight and Head Circumference (HC) under 34 cm was significantly higher in the preterm group. Mean gestational age was lower in mothers with cesarean delivery, high education, high economic status, high BMI, pre-pregnancy weight ≥ 65 kg and medical problem. Gestational age was inversely associated with maternal pre-pregnancy weight ≥ 65 kg (B= -0.20, p= 0.02), high BMI (B= -0.33, p= 0.01), high education (B= -0.47, p= 0.002) and cesarean delivery (B= -0.74, p< 0.001). The results indicate that maternal anthropometric characteristics, education and type of delivery are associated with gestational age. Explorating potentially modifiable risk factors for unfavorable gestational age and integrating them into intervention efforts may ameliorate adverse birth outcomes.