Clusters of week‐specific maternal gestational weight gain pattern and their association with birthweight: an observational cohort study

Introduction Gestational weight gain varies widely among different populations, and an inappropriate gestational weight gain is associated with adverse pregnancy outcomes. We aimed to investigate week‐specific serial changes in gestational weight gain in an urban Chinese population to derive clusters of gestational weight gain patterns and explore the impact of gestational weight gain patterns on birthweight. Material and methods This was an observational cohort study of 6130 women delivered at a university hospital in Shanghai, China. Pre‐pregnancy bodyweight, height, week‐specific and total gestational weight gain, pregnancy outcome and birthweight were extracted using electronic medical records. The association between gestational weight gain and gestational age was tested using linear regression, and week‐specific reference percentiles for gestational weight gain were calculated. Hierarchical clustering was used to derive gestational weight gain clusters. Mean birthweight among the clusters was compared using Dunnet's test. Results We found a significant linear association between gestational weight gain and gestational age (r = 0.56; p