Maternal BMI Changes from the Prepregnancy to Postpartum Period are Associated with Postpartum Cardiometabolic Risk Factors: A Longitudinal Study

Abstract Purpose To investigate the associations between the total body mass index(BMI) change at 3 or 4 years postpartum compared to the prepregnancy and cardiometabolic risk factors. Methods This longitudinal study included 1305 participants. Based on the total postpartum BMI changes, they were divided into < 0 units, 0-1.7 units, and > 1.7 units groups using the interquartile range. Multiple linear regression models were used to analyze the associations. Results Compared to the reference group, there was a progressive increase in the β coefficient ( β coef) of homeostasis model assessment of insulin resistance (HOMA-IR) of cardiometabolic risk in the following groups: the ‘0-1.7 units’ group with the ‘high prepregnancy BMI + high gestational weight gain (GWG) trajectory’ [βcoef 0.33; 95% confidence intervals (CI): 0.22, 0.44)] or the ‘very high prepregnancy BMI + very high GWG trajectory’ [0.66; (0.45, 0.88)] and the ‘>1.7 units’ group with the ‘normal prepregnancy BMI + normal GWG trajectory’ [0.33; (0.22, 0.44)], the ‘high prepregnancy BMI + high GWG trajectory’ [0.54; (0.41, 0.67)] or the ‘very high prepregnancy BMI + very high GWG trajectory’ [0.97; (0.79, 1.15)]. However, the ‘<0 units’ group with the ‘low prepregnancy BMI + low GWG trajectory’ [0.13; (0.06, 0.21)] and the ‘0-1.7 units’ group with the ‘low prepregnancy BMI + low GWG trajectory’ [0.08; (0.03, 0.13)] had higher high-density lipoprotein cholesterol (HDL-C) level than the reference group. Conclusion Women with a postpartum weight gain > 1.7 units are positively associated with cardiometabolic risk factors, especially those with a high prepregnancy BMI and high GWG. Conversely, women with a postpartum weight loss > 0 units have negative association with cardiometabolic risk factors.