In utero exposure to pre-existing or gestational diabetes increases incidence of diabetes in the children of First Nations and non-First Nations mothers: A retrospective cohort study

<jats:p>&lt;p dir="ltr"&gt;Objective: We conducted this First Nations engaged and co-led project to determine the incidence of diabetes in the children of mothers with pre-existing, gestational and no diabetes, and to evaluate whether periconception glycemic control was associated with the risk of diabetes in the children.&lt;/p&gt;&lt;p dir="ltr"&gt;Research Design and Methods: We conducted a longitudinal population-based study using healthcare administrative data that included all children of mothers aged 12–49 born between April 1994 and March 2016. The exposure of interest was maternal diabetes status, and we examined both First Nations and non-First Nations mothers. Children were followed for incident diabetes. Among women with pre-existing diabetes, periconception HbA1c was evaluated as a predictor.&lt;/p&gt;&lt;p dir="ltr"&gt;Results: There were 2,851,583 children followed to a median age of 16 years (interquartile range 11–22). Among children of non-First Nations mothers, the adjusted hazard ratios for incident diabetes were 5.18 (95% CI 4.82–5.57) with maternal pre-existing diabetes and 1.75 (1.65–1.84) with gestational diabetes. Among children of First Nations mothers, hazard ratios were 7.68 (5.91–9.98) and 2.59 (2.07–3.24), respectively. The hazard ratio for incident diabetes in children of mothers with pre-existing diabetes was 0.89 (95% CI 0.80–0.995, p=0.04) for each 1% (11 mmol/mol) decrease in periconception HbA1c.&lt;/p&gt;&lt;p dir="ltr"&gt;Conclusions: Exposure to both pre-existing and gestational diabetes in utero was associated with increased incidence of diabetes in children and young adults, with a stronger association among First Nations people. Better periconception glycemic control is associated with decreased diabetes incidence in children of mothers with pre-existing diabetes.&lt;/p&gt;</jats:p>