Subgroup and sensitivity analyses
There was substantial between-study heterogeneity (I 2 = 78.3%). Figure 2 presents the results of subgroup analyses for the types of exposure (LBW, preterm birth, or SGA). Although all types of exposure were associated with GDM, there was significant heterogeneity due to the type of exposure (p for interaction = 0.004). The results of additional sensitivity analyses are presented in Supplementary Figure S3, Figure S4, and Figure S5.