Interpretation
The results of this study are consistent with the association of healthy dietary patterns in pregnancy with lower odds of GDM17,20, HDP17,20, preterm birth16,19,20 and SGA19 reported in previous systematic reviews. These results highlight the potential benefits of a healthy diet on the regulation of glycaemia and systemic inflammation through the consumption of low glycemic-index foods and micronutrients3,67. We found no significant association between diet quality and excessive/inadequate gestational weight gain, LGA/macrosomia, and birthweight as a continuous variable. These results concord with previous research suggesting that energy intake, rather than diet quality, is the main driver of gestational weight gain and fetal growth67. No study evaluating the association of diet quality with delivery mode was identified. Only two cohorts (four studies) included measures of dietary quality in prepregnancy, which limited our ability to draw conclusions on subgroup analyses in prepregnancy. Studies were all of moderate or good quality and sensitivity analyses revealed consistent findings with the exclusion of moderate quality studies.