Multisystem Morbidity and Mortality in Offspring of Women With Type 1 Diabetes (the EPICOM Study): A Register-Based Prospective Cohort Study

Danish Diabetes Birth Registry 2: a study protocol of a national prospective cohort study to monitor outcomes of pregnancies of women with pre-existing diabetes

INTRODUCTION

Despite technological developments and intensified care, pregnancies in women with pre-existing diabetes are still considered high-risk pregnancies. The rate of adverse outcomes in pregnancies affected by diabetes in Denmark is currently unknown, and there is a limited understanding of mechanisms contributing to this elevated risk. To address these gaps, the Danish Diabetes Birth Registry 2 (DDBR2) was established. The aims of this registry are to evaluate maternal and fetal-neonatal outcomes based on 5 years cohort data, and to identify pathophysiology and risk factors associated with short-term and long-term outcomes of pregnancies in women with pre-existing diabetes.

METHODS AND ANALYSIS

The DDBR2 registry is a nationwide 5-year prospective cohort with an inclusion period from February 2023 to February 2028 of pregnancies in women with all types of pre-existing diabetes and includes registry, clinical and questionnaire data and biological samples of mother-partner-child trios. Eligible families (parents age ≥18 years and sufficient proficiency in Danish or English) can participate by either (1) basic level data obtained from medical records (mother and child) and questionnaires (partner) or (2) basic level data and additional data which includes questionnaires (mother and partner) and blood samples (all). The primary maternal outcome is Hemoglobin A1c (HbA1c) levels at the end of pregnancy and the primary offspring endpoint is the birth weight SD score. The DDBR2 registry will be complemented by genetic, epigenetic and metabolomic data as well as a biobank for future research, and the cohort will be followed through data from national databases to illuminate possible mechanisms that link maternal diabetes and other parental factors to a possible increased risk of adverse long-term child outcomes.

ETHICS AND DISSEMINATION

Approval from the Ethical Committee is obtained (S-20220039). Findings will be sought published in international scientific journals and shared among the participating hospitals and policymakers.

TRIAL REGISTRATION NUMBER

NCT05678543.

Maternal-fetal outcomes of pregnant women with type 1 diabetes treated with continuous subcutaneous insulin infusion or multiple daily injections during pregnancy - A Brazilian health care referral center cohort study

Objective

Pregnant women with type 1 diabetes (T1D) have an increased risk of maternal-fetal complications. Regarding treatment, continuous subcutaneous insulin infusion (CSII) has advantages compared to multiple daily injections (MDI), but data about the best option during pregnancy are limited. This study's aim was to compare maternal-fetal outcomes among T1D patients treated with CSII or MDI during pregnancy.

Subjects and methods

This study evaluated 174 pregnancies of T1D patients. Variables of interest were compared between the groups (CSII versus MDI), and logistic regression analysis was performed (p < 0.05).

Results

Of the 174 included pregnancies, CSII was used in 21.3% (37) and MDI were used in 78.7% (137). HbA1c values improved throughout gestation in both groups, with no difference in the first and third trimesters. The frequency of cesarean section was significantly higher in the CSII group [94.1 vs. 75.4%, p = 0.017], but there was no significant difference in the frequency of other complications, such as miscarriage, premature delivery and preeclampsia. The mean birth weight and occurrence of neonatal complications were also similar, except for the proportion of congenital malformations, which was significantly lower in the CSII group [2.9 vs. 15.6%, p = 0.048]. In regression analysis, the association of CSII with cesarean section and malformations lost significance after adjusting for HbA1c and other covariates of interest.

Conclusion

In this study, we observed a higher frequency of cesarean section and a lower occurrence of congenital malformations in the CSII group, but the adjusted results might indicate that these associations are influenced by glycemic control.

Hyperglycemia in Pregnancy and Women's Health in the 21st Century

Hyperglycemia is the commonest medical condition affecting pregnancy and its incidence is increasing globally in parallel with the twin epidemics of diabetes and obesity. Both pre-pregnancy diabetes and gestational diabetes are associated with short term pregnancy complications, with the risk of immediate complications generally broadly rising with more severe hyperglycemia. In this article we firstly consider these risks and their optimal management during pregnancy and then broaden our scope to consider the long-term implications of hyperglycemia in pregnancy as it relates to overall maternal and offspring health in a life course perspective.

Maternal hypertensive disorder of pregnancy and mortality in offspring from birth to young adulthood: national population based cohort study

OBJECTIVE

To examine the association of maternal hypertensive disorder of pregnancy (HDP) with overall and cause specific mortality in offspring from birth to young adulthood.

DESIGN

Nationwide population based cohort study.

SETTING

Danish national health registers.

PARTICIPANTS

All 2 437 718 individuals live born in Denmark, 1978-2018, with follow-up from date of birth until date of death, emigration, or 31 December 2018, whichever came first.

MAIN OUTCOME MEASURES

The primary outcome was all cause mortality. Secondary outcomes were 13 specific causes of death in offspring from birth to young adulthood (age 41 years). Cox regression was used to assess the association, taking into consideration several potential confounders. The role of timing of onset and severity of pre-eclampsia, maternal history of diabetes, and maternal education were also studied.

RESULTS

102 095 mothers had HDP: 67 683 with pre-eclampsia, 679 with eclampsia, and 33 733 with hypertension. During follow-up to 41 years (median 19.4 (interquartile range 9.7-28.7) years), deaths occurred in 781 (58.94 per 100 000 person years) offspring born to mothers with pre-eclampsia, 17 (133.73 per 100 000 person years) born to mothers with eclampsia, 223 (44.38 per 100 000 person years) born to mothers with hypertension, and 19 119 (41.99 per 100 000 person years) born to mothers with no HDP. The difference in cumulative incidence in overall mortality between cohorts exposed and unexposed to maternal HDP was 0.37% (95% confidence interval 0.11% to 0.64%), and the population attributable fraction for maternal HDP was estimated as 1.09% (95% confidence interval 0.77% to 1.41%). Maternal HDP was associated with a 26% (hazard ratio 1.26, 95% confidence interval 1.18 to 1.34) higher risk of all cause mortality in offspring. The corresponding estimates for maternal pre-eclampsia, eclampsia, and hypertension were 1.29 (1.20 to 1.38), 2.88 (1.79 to 4.63), and 1.12 (0.98 to 1.28). Increased risks were also observed for several cause specific mortalities, such as deaths from conditions originating in the perinatal period (2.04, 1.81 to 2.30), cardiovascular diseases (1.52, 1.08 to 2.13), digestive system diseases (2.09, 1.27 to 3.43), and endocrine, nutritional, and metabolic diseases (1.56, 1.08 to 2.27). The increased risks were more pronounced among offspring of mothers with early onset and severe pre-eclampsia (6.06, 5.35 to 6.86) or with both HDP and diabetes history (1.57, 1.16 to 2.14) or HDP and low education level (1.49, 1.34 to 1.66).

CONCLUSION

Maternal HDP, particularly eclampsia and severe pre-eclampsia, is associated with increased risks of overall mortality and various cause specific mortalities in offspring from birth to young adulthood.

Fetoplacental oxygen homeostasis in pregnancies with maternal diabetes mellitus and obesity

Despite improvements in clinical management, pregnancies complicated by pre-existing diabetes mellitus, gestational diabetes mellitus or obesity carry substantial risks for parent and offspring. Some of the endocrine and metabolic changes in parent and fetus in diabetes mellitus and obesity lead to fetal oxygen deficit, mostly due to insulin-induced accelerated fetal metabolism. The human fetus deals with reduced oxygenation through a wide range of adaptive responses that act at various levels in the placenta as well as the fetus. These responses ensure adequate oxygen delivery to the fetus, increase the oxygen transport capacity of fetal blood and redistribute oxygen-rich blood to vital organs such as the brain and heart. The liver has a central role in adapting to reduced oxygenation by increasing its oxygen extraction and stimulating erythropoietin synthesis to increase haematocrit. The type of adaptive response depends on the onset and duration of hypoxia and the severity of the metabolic disturbance. In pregnancies characterized by diabetes mellitus or obesity, these adaptive systems come under additional strain owing to the increased maternal supply of glucose and resultant fetal hyperinsulinaemia, both of which stimulate oxidative metabolism. In the rare situation that the adaptive responses are overwhelmed, stillbirth can ensue.

Fetal chronic hypoxia and oxidative stress in diabetic pregnancy. Could fetal erythropoietin improve offspring outcomes?

Oxidative stress is responsible for microvascular complications (hypertension, nephropathy, retinopathy, peripheral neuropathy) of diabetes, which during pregnancy increase both maternal and fetal complications. Chronic hypoxia and hyperglycemia result in increased oxidative stress and decreased antioxidant enzyme activity. However, oxidative stress induces also anti-oxidative reactions both in pregnant diabetes patients and in their fetuses. Not all type 1 diabetes patients with long-lasting disease develop microvascular complications, which suggests that some of these patients have protective mechanisms against these complications. Fetal erythropoietin (EPO) is the main regulator of red cell production in the mother and in the fetus, but it has also protective effects in various maternal and fetal tissues. This dual effect of EPO is based on EPO receptor (EPO-R) isoforms, which differ structurally and functionally from the hematopoietic EPO-R isoform. The tissue protective effects of EPO are based on its anti-apoptotic, anti-oxidative, anti-inflammatory, cell proliferative and angiogenic properties. Recent experimental and clinical studies have shown that EPO has also positive metabolic effects on hyperglycemia and diabetes, although these have not yet been fully delineated. Whether the tissue protective and metabolic effects of EPO could have clinical benefits, are important topics for future research in diabetic pregnancies.

Intergenerational Effects of Health Issues Among Women of Childbearing Age: a Review of the Recent Literature

PURPOSE OF REVIEW

This review summarizes the latest scientific evidence, primarily from systematic reviews/meta-analyses and large cohort studies, on the impact of health issues among women of childbearing age and their effect on their offspring during pregnancy and from birth to adulthood.

RECENT FINDINGS

Women of childbearing age with overweight/obesity, diabetes, and hypertension prior to pregnancy are at increased risk for adverse outcomes during pregnancy, such as excessive gestational weight gain, gestational diabetes mellitus, and hypertensive disorders of pregnancy. These adverse outcomes could complicate delivery and put their offspring at risk of developing overweight/obesity, diabetes, and hypertension (i.e., intergenerational transmission of health issues). Interventions should target women of childbearing age, especially those who wish to conceive, in order to possibly stop the transmission of women's health issues to the offspring and favor a healthy pregnancy from the start. This could be one of the best strategies to promote both maternal and child health.

Management of Preexisting Diabetes in Pregnancy: A Review

IMPORTANCE

The presence of preexisting type 1 or type 2 diabetes in pregnancy increases the risk of adverse maternal and neonatal outcomes, such as preeclampsia, cesarean delivery, preterm delivery, macrosomia, and congenital defects. Approximately 0.9% of the 4 million births in the United States annually are complicated by preexisting diabetes.

OBSERVATIONS

Women with diabetes have increased risk for adverse maternal and neonatal outcomes, and similar risks are present with type 1 and type 2 diabetes. Both forms of diabetes require similar intensity of diabetes care. Preconception planning is very important to avoid unintended pregnancies and to minimize risk of congenital defects. Hemoglobin A1c goals are less than 6.5% at conception and less than 6.0% during pregnancy. It is also critical to screen for and manage comorbid illnesses, such as retinopathy and nephropathy. Medications known to be unsafe in pregnancy, such as angiotensin-converting enzyme inhibitors and statins, should be discontinued. Women with obesity should be screened for obstructive sleep apnea, which is often undiagnosed and can result in poor outcomes. Blood pressure goals must be considered carefully because lower treatment thresholds may be required for women with nephropathy. During pregnancy, continuous glucose monitoring can improve glycemic control and neonatal outcomes in women with type 1 diabetes. Insulin is first-line therapy for all women with preexisting diabetes; injections and insulin pump therapy are both effective approaches. Rates of severe hypoglycemia are increased during pregnancy; therefore, glucagon should be available to the patient and close contacts should be trained in its use. Low-dose aspirin is recommended soon after 12 weeks' gestation to minimize the risk of preeclampsia. The importance of discussing long-acting reversible contraception before and after pregnancy, to allow for appropriate preconception planning, cannot be overstated.

CONCLUSIONS AND RELEVANCE

Preexisting diabetes in pregnancy is complex and is associated with significant maternal and neonatal risk. Optimization of glycemic control, medication regimens, and careful attention to comorbid conditions can help mitigate these risks and ensure quality diabetes care before, during, and after pregnancy.

Impact of type 1 diabetes on maternal long-term risk of hospitalisation and mortality: a nationwide combined clinical and register-based cohort study (The EPICOM study)

AIMS/HYPOTHESIS

The aims of this study were to examine long-term mortality and morbidity rates in mothers with type 1 diabetes, both overall and according to the level of albuminuria prior to pregnancy, the presence of hypertension, pre-eclampsia and periconceptional HbA_1c.

METHODS

This study was a part of the EPICOM (Environmental Versus Genetic and Epigenetic Influences on Growth, Metabolism and Cognitive Function in Offspring of Mothers with Type 1 Diabetes) study, which is a prospective follow-up study focusing on pregnancies complicated by maternal type 1 diabetes. We carried out a nationwide combined clinical and register-based cohort study of mortality rates and hospital admissions in mothers with diabetes (n = 986) who gave birth between 1992 and 2000. Control mothers (n = 91,441) were women from the background population, matched according to age and year of childbirth. Age at follow-up was 32-66 years.

RESULTS

Mortality rate was increased threefold in mothers with diabetes compared with control mothers (HR 3.41 [95% CI 2.42, 4.81]; p < 0.0001), and was also increased with pre-gestational kidney dysfunction (normoalbuminuria, HR 2.17 [95% CI 1.28, 3.68]; microalbuminuria, HR 3.36 [95% CI 0.82, 13.8]; macroalbuminuria, HR 12.9 [95% CI 5.45, 30.7]). Moreover, the presence of hypertension prior to or at any time during pregnancy and of pre-eclampsia also increased mortality rate (hypertension, HR 4.34 [95% CI 2.13, 8.84]; pre-eclampsia, HR 5.55 [95% CI 2.71, 11.4]). Mortality rate also increased with higher levels of HbA_1c in early pregnancy (HbA_1c ≤75 mmol/mol [≤9%], HR 2.15 [95% CI 1.31, 3.53]; HbA_1c >75 mmol/mol [>9%], HR 6.10 [95% CI 2.67, 14.0]). However, in mothers with diabetes and HbA_1c <64 mmol/mol (<8%) in the first trimester and normal pre-gestational urinary albumin excretion rate (n = 517), mortality rate was comparable with that of control mothers. Among mothers with diabetes, mortality rate was associated with HbA_1c level: per 11 mmol/mol (1 percentage point) increase in HbA_1c, HR was 1.52 (95% CI 1.19, 1.94; p = 0.001). In mothers with diabetes, the overall incidence of hospital admissions was more than double (incidence rate ratio [IRR] 2.69 [95% CI 2.59, 2.80]; p < 0.0001) that of control mothers, as were admissions with various diagnoses from 14 out of 19 ICD-10 chapters. Among mothers with diabetes, the IRR for hospital admissions increased with the level of HbA_1c: per 11 mmol/mol (1 percentage point) increase in HbA_1c, HR was 1.07 (95% CI 1.04, 1.10; p < 0.0001).

CONCLUSIONS/INTERPRETATION

Overall, mothers with type 1 diabetes have a two- to threefold increase in mortality and morbidity rates. HbA_1c levels, level of albuminuria around the time of conception, and the presence of hypertension and pre-eclampsia are important risk factors for mortality/morbidity in this cohort. However, it is reassuring that mothers with type 1 diabetes without kidney complications and with HbA_1c <64 mmol/mol (<8%) in early pregnancy have a similar survival potential during the period where they are raising their children to that of control mothers from the background population.

Two denominators for one numerator: the example of neonatal mortality

Preterm delivery is one of the strongest predictors of neonatal mortality. A given exposure may increase neonatal mortality directly, or indirectly by increasing the risk of preterm birth. Efforts to assess these direct and indirect effects are complicated by the fact that neonatal mortality arises from two distinct denominators (i.e. two risk sets). One risk set comprises fetuses, susceptible to intrauterine pathologies (such as malformations or infection), which can result in neonatal death. The other risk set comprises live births, who (unlike fetuses) are susceptible to problems of immaturity and complications of delivery. In practice, fetal and neonatal sources of neonatal mortality cannot be separated-not only because of incomplete information, but because risks from both sources can act on the same newborn. We use simulations to assess the repercussions of this structural problem. We first construct a scenario in which fetal and neonatal factors contribute separately to neonatal mortality. We introduce an exposure that increases risk of preterm birth (and thus neonatal mortality) without affecting the two baseline sets of neonatal mortality risk. We then calculate the apparent gestational-age-specific mortality for exposed and unexposed newborns, using as the denominator either fetuses or live births at a given gestational age. If conditioning on gestational age successfully blocked the mediating effect of preterm delivery, then exposure would have no effect on gestational-age-specific risk. Instead, we find apparent exposure effects with either denominator. Except for prediction, neither denominator provides a meaningful way to define gestational-age-specific neonatal mortality.

Differential effects of age and sex on insulin sensitivity and body composition in adolescent offspring of women with type 1 diabetes: results from the EPICOM study

AIMS/HYPOTHESIS

The aim of this study was to investigate the influence of age and sex on insulin sensitivity and insulin secretion in the adolescent offspring of women with type 1 diabetes, compared with the background population.

METHODS

This was a prospective nationwide follow-up study (Epigenetic, Genetic and Environmental Effects on Growth, Cognitive Functions and Metabolism in Offspring of Women with Type 1 Diabetes [EPICOM]) in a Danish population. We examined 278 offspring of women with type 1 diabetes from the Danish Diabetes Association Register born during 1993-1999 (index offspring) and 303 control offspring, identified through the Danish Central Office of Civil Registration and matched to the index offspring with respect to date of birth, sex and postal code. The offspring had an overall mean age of 16.7 years (range 13.0-20.4 years). The main outcomes were age-related changes in fasting OGTT-derived indices for insulin sensitivity (BIGTT-SI_0-30-120, Matsuda index, HOMA-IR) and insulin secretion (acute insulin response [BIGTT-AIR_0-0-30-120], insulinogenic index, HOMA of insulin secretory function [HOMA-β], disposition index) and physical activity (International Physical Activity Questionnaire). In addition, we determined total body fat (TBF) percentage using dual-energy x-ray absorptiometry.

RESULTS

We observed significantly lower insulin sensitivity in index offspring compared with control offspring, increasing with age. The differences were attenuated after adjustment for TBF percentage, but were still significant at 17 and 18 years of age. We also observed decreased disposition index and insulin secretion-sensitivity index-2 in index offspring at the same age, but we found no significant differences in other indices of insulin secretion compared with control offspring. With age, TBF percentage became increasingly more divergent between index and control offspring, and was consistently higher among female but not male index offspring.

CONCLUSIONS/INTERPRETATION

Differences in insulin sensitivity between the offspring of women with type 1 diabetes and control offspring increased with age. This was only partially explained by higher adiposity in the index offspring.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01559181.

Abnormal levels of adipokines in adolescent offspring of women with type 1 diabetes - Results from the EPICOM study

AIMS/HYPOTHESIS

To investigate long-term consequences of diabetes during pregnancy, we determined adiponectin and leptin levels in adolescents born by women with type 1 diabetic (T1D) or non-diabetic mothers, and determined associations between adiponectin and leptin levels in adolescence and the magnitude of intrauterine hyperglycemia.

RESEARCH DESIGN AND METHODS

We measured serum adiponectin and leptin and calculated leptin to adiponectin ratio (LAR) in 271 offspring of T1D women (index offspring) (13-20years), and 297 matched control offspring. Anthropometry included total body fat (TBF) by dual-energy X-ray absorptiometry and an oral glucose tolerance test.

RESULTS

Adiponectin levels were lower in index females (-8.0% (95% CI; -13.9, -1.6)), but not in index males (0.4% (95% CI; -7.3, 8.6)). Leptin levels were approximately 30% higher in index than control offspring, irrespective of gender. In males, this was seen despite similar TBF in index and control offspring. LAR was increased in index offspring (both males and females) compared with control offspring. There were no association between offspring adiponectin and maternal HbA1c levels in pregnancy. Leptin and LAR seemed to be associated with third trimester HbA1c levels in females in unadjusted, but not adjusted analyses.

CONCLUSION

Male and female offspring of women with T1D demonstrated increased serum leptin and LAR, whereas serum adiponectin was reduced in females only. These results suggest that abnormal regulation of adipokines is a consequence of being born to mothers with T1D. No direct association between maternal glycemic control and adiponectin and leptin levels or LAR in the adolescence was found.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01559181.

Mortality and morbidity in offspring of mothers with diabetes compared with a population group: a Danish cohort study with 8-35 years of follow-up

AIMS

To assess mortality and morbidity in the offspring of mothers with diabetes compared with a control cohort of offspring of mothers without diabetes.

METHODS

The mortality rate, percentage of days admitted to hospital, diagnostic categories and incidence of diabetes mellitus among 691 offspring of mothers with diabetes were compared with a control group of 168 831 offspring not exposed to maternal diabetes. Offspring of mothers with diabetes were identified from the North Jutland Pregnancy database (521 Type 1; 34 Type 2; 136 gestational diabetes) born between 1976 and 2003. Outcome data were retrieved from the National Registry of Patients with follow-up until 31 December 2011. In a subgroup with the longest hospital stay we reviewed hospital records for clinical details until 2016.

RESULTS

Mortality was 1.45% in the diabetes group compared with 1.36% in the control group. In the first 2 years, offspring exposed to diabetes spent significantly more time in hospital than the control offspring, but this difference faded to an insignificant difference of 0.04% of time spent in hospital between age 2 and 8 years. The offspring of mothers with diabetes had a sixfold increased risk of developing diabetes mellitus.

CONCLUSIONS

The offspring of mothers with and without diabetes had almost identical mortality. The increased morbidity was restricted to the first 2 years of life, and was primarily attributable to a few individuals with very severe but probably non-diabetes-related disease burden. The large majority of offspring of mothers with diabetes experienced health conditions similar to those not exposed to diabetes.

Long-term Cognitive Implications of Intrauterine Hyperglycemia in Adolescent Offspring of Women With Type 1 Diabetes (the EPICOM Study)

OBJECTIVE

Exposure to maternal diabetes in utero may have a negative impact on the developing brain. The objective was to examine long-term cognitive consequences of intrauterine hyperglycemia in adolescent offspring of women with type 1 diabetes and to ascertain a possible association with maternal HbA1c.

RESEARCH DESIGN AND METHODS

Offspring of a prospectively followed cohort of women with type 1 diabetes (n = 277) participated in a follow-up examination at the age of 13-19 years. A control group from the background population was identified (n = 301). Cognitive function was evaluated using Reynolds Intellectual Assessment Scales and classified into indices of composite intelligence, verbal and nonverbal intelligence, and composite memory. Frequencies of reading and writing problems and attendance to classes for children with learning difficulties were assessed.

RESULTS

Offspring of women with type 1 diabetes scored lower in all normalized and standardized intelligence indices compared with controls: composite intelligence (95.7 vs. 100, P = 0.001), verbal intelligence (96.2 vs. 100, P = 0.004), nonverbal intelligence (96.4 vs. 100, P = 0.008), and composite memory (95.7 vs. 100, P = 0.001). A higher frequency of diabetes-exposed offspring had parent-reported learning difficulties in primary school. Differences between groups remained after adjustment for confounders and potential mediators. We found no direct association between maternal HbA1c and offspring cognitive function in the exposed group.

CONCLUSIONS

Adolescent offspring of women with type 1 diabetes had lower cognitive function compared with a control group, also after adjustment for confounders and potential mediators. These differences may reflect direct harmful effects of maternal diabetes on neurodevelopment in the offspring.

Increased metabolic risk in adolescent offspring of mothers with type 1 diabetes: the EPICOM study

AIMS/HYPOTHESIS

We aimed to investigate metabolic risk factors, insulin sensitivity and insulin secretion in adolescent offspring of mothers with type 1 diabetes compared with offspring of non-diabetic mothers.

METHODS

During 1993-1999, pregnancies of women with type 1 diabetes in Denmark were prospectively reported to a central registry in the Danish Diabetes Association. Data included information on maternal demography, diabetes status and pregnancy outcome. We invited 746 eligible children from this cohort (index offspring) to a follow-up examination. Control offspring were identified through The Danish Central Office of Civil Registration and matched with respect to date of birth, sex and postal code. Anthropometric measurements and blood sampling for metabolic characterisation, including an oral glucose tolerance test, were performed.

RESULTS

We examined 278 index offspring (mean age 16.7 years; range 13.0-19.8 years) and 303 control offspring (mean age 16.8 years; range 13.5-20.4 years). Index offspring had higher BMI SD score (0.44: 95% CI 0.21, 0.66) compared with controls, after adjustments for pubertal development and maternal pre-pregnancy BMI. Furthermore, index offspring had a higher prevalence of components included in metabolic syndrome and prediabetes (impaired fasting glucose and/or impaired glucose tolerance), with reduced insulin sensitivity and relative insulin secretion deficiency, compared with controls. Maternal HbA1c levels in pregnancy were not directly associated with offspring metabolic outcomes.

CONCLUSIONS/INTERPRETATION

Adolescent offspring of mothers with type 1 diabetes had a less favourable metabolic profile and higher frequency of prediabetes than the background population. Significant associations between these outcomes and maternal HbA1c levels in pregnancy could not be demonstrated.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01559181.