Strengths and limitations
hyperglycaemia, diabetes
HYPERGLYCAEMIA, INSULIN RESISTANCE, DIABETES
This study has two main strengths in its investigation of the association between maternal and offspring metabolism. First, we examined serum levels of glucose and insulin which are objective measures of the offspring outcomes and maternal exposures. Second, a variety of relevant covariates were collected through study visits and questionnaires during pregnancy and at 7- and 9-year follow-ups, including both potential hereditary and lifestyle confounding factors.There are inherent limitations to the analysis. The sample size is small, which limits the study’s power to demonstrate associations. Though associations between investigated exposures and outcomes were positive, confidence intervals were wide, and p-values did not meet the set significance level at < 0.05. Moreover, the study was not originally designed to examine the long-term effects of maternal hyperglycaemia in pregnancy, and no a-priori power calculation was performed. Though the study is generally well adjusted for confounders, we did not have access to relevant paternal factors, such as diabetes, BMI, and socioeconomic status.Offspring fasting blood samples were analysed in this study. It is possible that glucose tolerance (1- or 2-hour glucose), obtained following a 75-gram glucose load, would be more sensitive in identifying abnormal glucose metabolism in children, as argued in a systematic review by The OGTT was performed at ~34 weeks of gestation in the present study, in contrast to many other studies, and screening programs in most countries, where testing in week 24-28 is recommended. This is of importance when comparing results with other studies, as glucose metabolism changes during a normal pregnancy, with decreasing fasting glucose and increasing non-fasting glucose and insulin resistance with advancing gestation (It is possible that the present study might be exposed to some degree of selection bias, in favour of healthier mother-child pairs. 74% of the eligible mother-child pairs from the 7-year follow-up participated in this 9-year follow-up study. However, only 18% of the mother-child pairs included in the original study in Trondheim participated in the present follow-up study. Participating mothers had higher socioeconomic position and lower third trimester fasting glucose than non-participants, though other characteristics were similar between the groups. It is also reasonable to assume that women who agreed to participate in the initial RCT might be healthier than the general population, as it was an exercise study. Compared with data from the medical birth registry of Norway (MBRN) in 2021 (Comparison with the ungKan3 study (