“…Twenty-five studies focused on the association between pre-pregnancy BMI or weight (referred to hereafter as ‘pre-pregnancy BMI’) and a range of maternal and child health outcomes ( Table 2 ) [ 10 , 41 , 42 , 46 , 47 , 49 , 50 , 51 , 53 , 55 , 56 , 60 , 62 , 64 , 66 , 67 , 72 , 73 , 75 , 85 , 86 , 91 , 93 , 94 , 95 ]. In general, these studies found associations between a higher pre-pregnancy BMI and adverse maternal and child health outcomes, including gestational diabetes [ 41 , 47 , 51 , 56 , 73 , 75 ], gestational hypertension [ 42 , 50 , 51 ], pre-eclampsia [ 93 ], caesarean section [ 51 , 93 ], high birthweight [ 51 , 55 , 67 , 72 , 85 ], and developing diabetes after pregnancy [ 53 ]. Reported relationships between pre-pregnancy BMI and gestational weight gain were not consistent across studies [ 49 , 55 ], and several studies found no association with a preterm birth [ 64 , …”