Influence of pre-pregnancy obesity on the development of macrosomia and large for gestational age in women with or without gestational diabetes mellitus in Chinese population

OBJECTIVE: To determine the effects of gestational diabetes mellitus (GDM) and pre-pregnancy obesity on macrosomia and large for gestational age (LGA). STUDY DESIGN: We conducted a prospective cohort study of 587 GDM women and 478 non-GDM women from 2012 to 2013. We collected their data of the pre-pregnancy weight, sociodemographic data, medical histories, clinical treatment, and followed-up the outcomes of delivery including birth weight. Multiple logistic regression models were used to test associations between pre-pregnant obesity and macrosomia/LGA and between GDM and macrosomia/LGA. RESULT: Of 1065 women we studied, obese women had 4.17 times and 2.27 times increased risk of developing macrosomia (95% CI: 2.52 to 6.91) and LGA (95% CI: 1.60 to 3.21), respectively, than non-obese women after adjustment for maternal age, gestational weeks and GDM. We did not find GDM is a risk factor for macrosomia or LGA after GDM treatment. CONCLUSION: Pre-pregnancy obesity accounts for a high prevalence of macrosomia. Interventions that focus on pre-pregnancy obesity have the potential to reach far more women at risk of macrosomia.