The Effect of Body Mass Index Changes between Two Consecutive Pregnancies on the Recurrence of Gestational Diabetes Mellitus in Japan

Abstract

Aim: To identify the effect of interpregnancy pre-pregnancy body mass index changes (ΔBMI) on the recurrence of gestational diabetes mellitus (GDM). Method: A cross sectional study was conducted comprising 183 cases diagnosed with GDM at least once in two consecutive pregnancies. Study cases were divided into three groups based on two consecutive glucose tolerance profiles that comprised normal glucose tolerance (NGT); GDM/GDM (n=45), GDM/NGT (n=33), and NGT/GDM (n=105). We compared ΔBMI among the groups. Study cases were then divided into subgroups on the basis of being below or above the median pre-pregnancy BMI at index pregnancy and ΔBMI was compared based on glucose tolerance profiles. Results: The NGT/GDM group had the highest ΔBMI (1.01±2.06) among the 3 groups. The GDM/GDM group had a higher ΔBMI (0.52±1.59) compared with the GDM/NGT group (-0.41±1.50, p<0.01). The median pre-pregnancy BMI at index pregnancies was 21.2. In the GDM/NGT group, there was no difference in ΔBMI below or above the pre-pregnancy BMI of 21.2 (p=0.66). In the GDM/GDM group, there was no difference in ΔBMI below or above the pre-pregnancy BMI of 21.2 (p=0.97). In cases that fell below the pre-pregnancy BMI of 21.2, the GDM/NGT group was associated with a lower ΔBMI (-0.28±1.13) compared with the GDM/GDM group (0.51±1.23, p<0.05). In cases above the pre-pregnancy BMI of 21.2, there was no difference in ΔBMI between GDM/NGT (-0.64±2.04) and GDM/GDM groups (0.52±1.82, p=0.11). Conclusion: Subtle changes in ΔBMI are associated with GDM recurrence, and reduced ΔBMI suppresses GDM recurrence in Japanese lean women.