Neurocognitive and behavioural outcomes in offspring exposed to maternal pre-existing diabetes: a systematic review and meta-analysis

We performed a systematic review and meta-analysis to determine whether exposure to maternal pre-existing diabetes in pregnancy is associated with neurocognitive or behavioural outcomes in offspring. We searched MEDLINE, EMBASE, PsychINFO, the Cochrane Database of Systematic Reviews and Scopus for studies that examined any neurocognitive or behavioural outcomes in offspring of mothers with pre-existing diabetes in pregnancy in accordance with a published protocol (PROSPERO CRD42018109038). Title and abstract review, full-text review and data extraction were performed independently and in duplicate. Risk of bias was assessed using the Newcastle–Ottawa scale. Meta-analyses of summary measures were performed using random-effects models. Nineteen articles including at least 18,681 exposed and 2,856,688 control participants were identified for inclusion. Exposure to maternal pre-existing diabetes in pregnancy was associated with a lower pooled intelligence quotient in the offspring (pooled weighted mean difference −3.07 [95% CI −4.59, −1.55]; I2 = 0%) and an increased risk of autism spectrum disorders (effect estimate 1.98 [95% CI 1.46, 2.68]; I2 = 0%). There was also an increased risk of attention deficit/hyperactivity disorder (pooled HR 1.36 [95% CI 1.19, 1.55]; I2 = 0%), though this was based on only two studies. Although most studies were found to be high quality in terms of participant selection, in many studies, comparability of cohorts and adequacy of follow-up were sources of bias. There is evidence to suggest that in utero exposure to maternal pre-existing diabetes is associated with some adverse neurocognitive and behavioural outcomes. It remains unclear what the role of perinatal factors is and the degree to which other environmental factors contribute to these findings.