Association between body mass index and weight gain during pregnancy with preterm delivery

  Background : In previous studies, the relationship between body mass index (BMI), weight gain during pregnancy, pregnancy outcome and preterm delivery is inconsistent .   Objective: The aim of this study was to determine the association between body mass index and weight gain during pregnancy with preterm delivery.   Methods: This analytical study was performed in Qazvin province during 2010 and 2011. 1650 pregnant woman aged 18 to 35 years old with gestational age less than 12 weeks were selected. 274 subjects were excluded due to underlying diseases, premature rupture of membrane (PROM) or incomplete prenatal care. Body Mass Index (BMI) were measured. Weight gain during pregnancy and preterm labor (before 37 weeks of gestation) were documented. Data were analyzed by T-Test and Chi-square test.   Findings: The incidence of preterm delivery in women with lower BMI was higher than other pregnant women, but the difference was not statistically significant. The incidence of preterm delivery in normal weight and overweight women with weight gain during pregnancy less than recommended was higher than others (P=0.02 , P=0.01). Our results in this study showed the BMI and weight gain during pregnancy were significant in predicting preterm delivery.   Conclusion: This study showed that there is an association between BMI and abnormal weight gain during pregnancy with preterm delivery. Therefore, education programs, health services and nutrition consultation are recommended for women in reproductive age.