Impact of pre-pregnancy BMI and gestational weight gain on adverse pregnancy outcomes in Chinese women with gestational diabetes mellitus: A systematic review and meta-analysis

Abstract Background Pre-pregnancy BMI and gestational weight gain are associated with pregnancy outcomes. This review aimed to explore pregestational BMI and gestational weight gain and their association with pregnancy complications in Chinese women with gestational diabetes mellitus. Moreover, the prevalence of inappropriate weight gain during pregnancy among them was estimated. Methods Nine databases including PubMed, Web of Science, Cochrane Library, Embase, Scopus, CNKI, Wangfang, VIP, and China Biology Medicine disc were searched from inception to March 2022. Outcomes evaluated were macrosomia, large for gestational age (LGA), small for gestational age (SGA), low birth weight (LBW), preterm birth, cesarean section (CS), and gestational hypertension (GH). Two researchers independently assessed the eligibility and quality of included studies and extracted data. Fixed and random effect models were used to pool the results. I2 index was used to assess the statistical heterogeneity. All analyses were performed using Stata software. Results 13,831 potential studies were identified, and 19 studies remain after removing duplicate and unrelated articles. Pregestational obesity and excess gestational weight gain are association with a higher risk of macrosomia (OR=2.83[2.13 to 3.77]; OR=2.13[1.92 to 2.38]), LGA (OR=3.38[2.71 to 4.23]; OR=2.15[1.82 to 2.53]), CS (OR=2.46[2.04 to 2.98]; OR=1.38[1.41 to 1.66]), and GH (OR=4.42[1.72 to 11.34]; OR=2.20[1.71 to 2.82]). Pregestational underweight and insufficient gestational weight gain are related to a higher risk of SGA (OR=1.90[1.63 to 2.22]; OR=1.34[1.22 to 1.48]) and LBW (OR=2.48[1.41 to 4.36]; OR=1.89[1.38 to 2.60]). As to preterm birth, the conclusion remains unclear. The prevalence of excess and below the weight gain recommendations of the Institute of Medicine is up to 35.5% and 27.3%. Gestational diabetes may have a potential synergistic effect with inappropriate weight changes, which needs to be further explored. Conclusion Weight management before and during pregnancy is crucial for all women including Chinese women with gestational diabetes.