Dose-Response Relationship between Gestational Weight Gain and Neonatal Birthweight in Chinese Women with Excess Weight/Obesity and Gestational Diabetes Mellitus

Total gestational weight gain (GWG) is identified as a strong and potentially controllable predictor of long-term health outcomes in women with gestational diabetes mellitus (GDM) and infants. When the total GWG of women with excess weight/obesity and GDM does not exceed the Institute of Medicine (IOM) suggested range, neonatal birthweight outcomes may be favorable, but the evidence is limited. Therefore, the objective of this study was to evaluate the dose-response relationship between increased total GWG and the risk of neonatal birthweight in Chinese women with excess weight/obesity and GDM. This study obtained electronic medical records (EMR) from the hospital information system (HIS) of the Chongqing Health Center for Women and Children between July 2017, and June 2020. A retrospective study analyzed the effect of the total GWG of women with excess weight/obesity and GDM on neonatal birthweight. The dose-response relationship between total GWG and neonatal birthweight was studied using a generalized linear model and embedded restricted cubic splines (RCS). The average age of all women with GDM was 31.99 ± 4.47 years, and 27.61% were advanced maternal age (≥35 years). The total GWG among women with excess weight and obesity and GDM greater than the IOM recommendations were found in 42.96% and 58.62% of cases, respectively. Total GWG in women with excess weight and excessing the IOM recommended range is a risk factor for large gestational age (LGA) [adjusted odds ratio (aOR) 0.1.47, 1.08–2.01] and macrosomia (aOR 1.55, 1.04–2.31). In the obesity above group, excessive weight gain increased the risk of LGA (aOR 2.92, 1.33–6.41) and macrosomia (aOR 2.83, 1.03–7.72). We used an RCS to examine pregnant women with excess weight and GDM and discovered a linear dose-response relationship between total GWG and LGA/macrosomia. In women with excess weight and obesity, increases in total GWG above the lowest end of the IOM recommendations range (7 kg and 5 kg) were associated with an increased risk of LGA and macrosomia. Therefore, research is urgently needed to support maternal and newborn health to provide recommendations for the ideal weight increase in women with excess weight/obesity and GDM.