Maternal overweight and obesity and its association with metabolic changes and fetal overgrowth in the absence of gestational diabetes mellitus: A prospective cohort study

INTRODUCTION

Previous studies indicated an association between fetal overgrowth and maternal obesity independent of gestational diabetes mellitus (GDM). However, the underlying mechanisms beyond this possible association are not completely understood. This study investigates metabolic changes and their association with fetal and neonatal biometry in overweight and obese mothers who remained normal glucose-tolerant during gestation.

MATERIAL AND METHODS

In this prospective cohort study 893 women who did not develop GDM were categorized according to their pregestational body mass index (BMI): 570 were normal weight, 220 overweight and 103 obese. Study participants received a broad metabolic evaluation before 16 weeks and were followed up until delivery to assess glucose levels during the oral glucose tolerance test (OGTT) at mid-gestation as well as fetal biometry in ultrasound and pregnancy outcome data.

RESULTS

Increased maternal BMI was associated with an adverse metabolic profile at the beginning of pregnancy, including a lower degree of insulin sensitivity (as assessed by the quantitative insulin sensitivity check index) in overweight (mean difference: -2.4, 95% CI -2.9 to -1.9, p < 0.001) and obese (mean difference: -4.3, 95% CI -5.0 to -3.7, p < 0.001) vs normal weight women. Despite not fulfilling diagnosis criteria for GDM, overweight and obese mothers showed higher glucose levels at fasting and during the OGTT. Finally, we observed increased measures of fetal subcutaneous tissue thickness in ultrasound as well as higher proportions of large-for-gestational-age infants in overweight (18.9%, odds ratio [OR] 1.74, 95% CI 1.08-2.78, p = 0.021) and obese mothers (21.0%, OR 1.99, 95% CI 1.06-3.59, p = 0.027) vs normal weight controls (11.8%). The risk for large for gestational age was further determined by OGTT glucose (60 min: OR 1.11, 95% CI 1.02-1.21, p = 0.013; 120 min: OR 1.13, 95% CI 1.02-1.27, P = 0.025, for the increase of 10 mg/dL) and maternal triglyceride concentrations (OR 1.11, 95% CI 1.01-1.22, p = 0.036, for the increase of 20 mg/dL).

CONCLUSIONS

Mothers affected by overweight or obesity but not GDM had a higher risk for fetal overgrowth. An impaired metabolic milieu related to increased maternal BMI as well as higher glucose levels at mid-gestation may impact fetal overgrowth in women still in the range of normal glucose tolerance.

The impact of regional origin on the incidence of gestational diabetes mellitus in a multiethnic European cohort

Introduction

Women with migration background present specific challenges related to risk stratification and care of gestational diabetes mellitus (GDM). Therefore, this study aims to investigate the role of ethnic origin on the risk of developing GDM in a multiethnic European cohort.

Methods

Pregnant women were included at a median gestational age of 12.9 weeks and assigned to the geographical regions of origin: Caucasian Europe (n = 731), Middle East and North Africa countries (MENA, n = 195), Asia (n = 127) and Sub-Saharan Africa (SSA, n = 48). At the time of recruitment maternal characteristics, glucometabolic parameters and dietary habits were assessed. An oral glucose tolerance test was performed in mid-gestation for GDM diagnosis.

Results

Mothers with Caucasian ancestry were older and had higher blood pressure and an adverse lipoprotein profile as compared to non-Caucasian mothers, whereas non-Caucasian women (especially those from MENA countries) had a higher BMI and were more insulin resistant. Moreover, we found distinct dietary habits. Non-Caucasian mothers, especially those from MENA and Asian countries, had increased incidence of GDM as compared to the Caucasian population (OR 1.87, 95%CI 1.40 to 2.52, p < 0.001). Early gestational fasting glucose and insulin sensitivity were consistent risk factors across different ethnic populations, however, pregestational BMI was of particular importance in Asian mothers.

Discussion

Prevalence of GDM was higher among women from MENA and Asian countries, who already showed adverse glucometabolic profiles at early gestation. Fasting glucose and early gestational insulin resistance (as well as higher BMI in women from Asia) were identified as important risk factors in Caucasian and non-Caucasian patients.

Glucometabolic Alterations in Pregnant Women with Overweight or Obesity but without Gestational Diabetes Mellitus: An Observational Study

INTRODUCTION

Maternal overweight is a risk factor for gestational diabetes mellitus (GDM). However, emerging evidence suggests that an increased maternal body mass index (BMI) promotes the development of perinatal complications even in women who do not develop GDM. This study aims to assess physiological glucometabolic changes associated with increased BMI.

METHODS

Twenty-one women with overweight and 21 normal weight controls received a metabolic assessment at 13 weeks of gestation, including a 60-min frequently sampled intravenous glucose tolerance test. A further investigation was performed between 24 and 28 weeks in women who remained normal glucose tolerant.

RESULTS

At baseline, mothers with overweight showed impaired insulin action, whereby the calculated insulin sensitivity index (CSI) was lower as compared to normal weight controls (3.5 vs. 6.7 10-4 min-1 [microU/mL]-1, p = 0.025). After excluding women who developed GDM, mothers with overweight showed higher average glucose during the oral glucose tolerance test (OGTT) at the third trimester. Moreover, early pregnancy insulin resistance and secretion were associated with increased placental weight in normal glucose-tolerant women.

CONCLUSION

Mothers with overweight or obesity show an unfavorable metabolic environment already at the early stage of pregnancy, possibly associated with perinatal complications in women who remain normal glucose tolerant.

Prevalence of gestational diabetes mellitus in women with a family history of type 2 diabetes in first- and second-degree relatives

AIMS

A family history of type 2 diabetes mellitus (T2DM) markedly increases an individual's lifetime risk of developing the disease. For gestational diabetes (GDM), this risk factor is less well characterized. This study aimed to investigate the relationship between family history of T2DM in first- and second-degree relatives in women with GDM and the differences in metabolic characteristics at early gestation.

METHODS

This prospective cohort study included 1129 pregnant women. A broad risk evaluation was performed before 16 + 0 weeks of gestation, including a detailed family history of the different types of diabetes and a laboratory examination of glucometabolic parameters. Participants were followed up until delivery and GDM assessed according to the latest diagnosis criteria.

RESULTS

We showed that pregnant women with first- (FHD1, 26.6%, OR 1.91, 95%CI 1.16 to 3.16, p = 0.005), second- (FHD2, 26.3%, OR 1.88, 95%CI 1.16 to 3.05, p = 0.005) or both first- and second-degree relatives with T2DM (FHD1 + D2, 33.3%, OR 2.64, 95%CI 1.41 to 4.94, p < 0.001) had a markedly increased risk of GDM compared to those with negative family history (FHN) (n = 100, 15.9%). The association was strongest if both parents were affected (OR 4.69, 95%CI 1.33 to 16.55, p = 0.009). Women with FHD1 and FHD1 + D2 had adverse glucometabolic profiles already in early pregnancy.

CONCLUSIONS

Family history of T2DM is an important risk factor for GDM, also by applying the current diagnostic criteria. Furthermore, we showed that the degree of kinship plays an essential role in quantifying the risk already at early pregnancy.

Assessment of glucose levels in pregnant women with history of COVID-19 in a case-control study

Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection may negatively affect glucose metabolism. This study aims to assess glucose levels, prevalence of gestational diabetes mellitus (GDM) and perinatal outcome in women with history of COVID-19. To this purpose, a group of 65 patients with history of COVID-19 and 94 control patients were retrospectively recruited among pregnant women who attended the pregnancy outpatient department between 01/2020 and 02/2022. Glucose data from an oral glucose tolerance test (OGTT), GDM status and obstetric complications were assessed. We observed no differences in average (p = 0.37), fasting (p = 0.62) or post-load glucose concentrations (60 min: p = 0.19; 120 min: p = 0.95) during OGTT. A total of 15 (23.1%) women in the COVID-19 group and 18 (19.1%) women in the control group developed GDM (p = 0.55). Moreover, caesarean section rate, weight percentiles and pregnancy outcomes were comparable between the groups (p = 0.49). In conclusion, in this study we did not identify a possible impact of COVID-19 on glucose metabolism in pregnancy, especially with regard to glucose concentrations during the OGTT and prevalence of GDM.

Fatty liver indices and their association with glucose metabolism in pregnancy - An observational cohort study

AIMS

Non-invasive hepatic steatosis indices can be used to assess the risk for metabolic (dysfunction) associated fatty liver disease (MAFLD). This may be helpful to detect metabolic disorders in pregnancy, specifically gestational diabetes (GDM). We aimto examine the association of these indices with parameters of glucose metabolism.

METHODS

109 women underwent a metabolic characterization at 16 weeks of gestation andwere classified according to the fatty-liver index (FLI) andhepatic-steatosis index (HSI) into low (G1), intermediate (G2) and high risk (G3). At 26 weeks, participants received an oral glucose tolerance test (OGTT) to assess insulin action, β-cell function and GDM status.

RESULTS

Both MAFLD indices wereassociated with impaired insulin sensitivityand compensatory increase of insulin release. G3 groups showedimpaired insulin action. The higher circulating insulin concentrations were not able to compensate for insulin resistance in women with higher MAFLD scores, resulting in an increased risk of GDM(OR: 1.05, 95% CI 1.03 to 1.08, p < 0.001 for FLI). MAFLD scores were associated with fetal overgrowth.

CONCLUSIONS

Maternal MAFLD represents a high-risk obstetric condition. Hepatic steatosis indices are associated with impaired glucose regulation and may provide a useful tool for early risk assessment for impaired glucose metabolism.

Fetal Growth and Adipose Fat Tissue Trajectories in Twin Pregnancies after Gastric Bypass Surgery

INTRODUCTION

Previous studies demonstrated a continuous decline in fetal growth throughout singleton pregnancy after bariatric surgery. However, intrauterine growth in twin pregnancy is subjected to further underlying processes. This study was to investigate the longitudinal assessment of fetal biometry and abdominal fat thickness of twin pregnancies conceived after gastric bypass (GB) surgery and compare them to body mass index-matched (BMIM) and obese (OB) controls.

MATERIALS AND METHODS

We retrospectively assessed ultrasound data of 30 women with dichorionic-diamniotic twin pregnancy (11 women after GB surgery, 9 OB mothers with pregestational BMI ≥30 kg/m2, and 10 BMIM and age-matched controls). We assessed fetal growth parameters including fetal subcutaneous adipose tissue thickness (FSCTT) as well as newborn biometry after delivery. Patient characteristics were obtained from the medical records.

RESULTS

The rise in FSCTT curves was markedly slower in the twin offspring of women with history of GB as compared to the offspring of OB mothers and offspring of BMIM controls. Hence, FSCTT was significantly decreased in the GB offspring as compared to both control groups at 34 weeks of gestation. Also, growth curves of abdominal circumference were decreased in the offspring of GB patients as compared to OB mothers. Infants of mothers with history of GB showed significantly lower birth weight percentiles compared to newborns of OB mothers (27.2 vs. 48.8 pct, p = 0.025). There was no significant difference in inter-twin birth weight difference between the offspring of GB (median: 9.9%, interquartile ranges [IQR]: 6.5-20.0) versus OB (median: 14.6%, IQR: 8.2-21.6) and BMIM controls (median: 9.0%, IQR: 6.3-12.6, p = 0.714).

CONCLUSIONS

In summary, intrauterine growth delay in twin pregnancies after GB is assumed to be a multifactorial event with altered metabolism as the most important factor. However, special attention must be paid to the particularity of twin pregnancies as they seem to be subject to other additional mechanism.

Performance of early risk assessment tools to predict the later development of gestational diabetes

BACKGROUND

Several prognostic models for gestational diabetes mellitus (GDM) are provided in the literature; however, their clinical significance has not been thoroughly evaluated, especially with regard to application at early gestation and in accordance with the most recent diagnostic criteria. This external validation study aimed to assess the predictive accuracy of published risk estimation models for the later development of GDM at early pregnancy.

METHODS

In this cohort study, we prospectively included 1132 pregnant women. Risk evaluation was performed before 16 + 0 weeks of gestation including a routine laboratory examination. Study participants were followed-up until delivery to assess GDM status according to the IADPSG 2010 diagnostic criteria. Fifteen clinical prediction models were calculated according to the published literature.

RESULTS

Gestational diabetes mellitus was diagnosed in 239 women, that is 21.1% of the study participants. Discrimination was assessed by the area under the ROC curve and ranged between 60.7% and 76.9%, corresponding to an acceptable accuracy. With some exceptions, calibration performance was poor as most models were developed based on older diagnostic criteria with lower prevalence and therefore tended to underestimate the risk of GDM. The highest variable importance scores were observed for history of GDM and routine laboratory parameters.

CONCLUSIONS

Most prediction models showed acceptable accuracy in terms of discrimination but lacked in calibration, which was strongly dependent on study settings. Simple biochemical variables such as fasting glucose, HbA1c and triglycerides can improve risk prediction. One model consisting of clinical and laboratory parameters showed satisfactory accuracy and could be used for further investigations.

Characteristics of gestational diabetes subtypes classified by oral glucose tolerance test values

BACKGROUND

In clinical practice, gestational diabetes mellitus (GDM) is treated as a homogenous disease but emerging evidence suggests that the diagnosis of GDM possibly comprises different metabolic entities. In this study, we aimed to assess early pregnancy characteristics of gestational diabetes mellitus entities classified according to the presence of fasting and/or post-load hyperglycaemia in the diagnostic oral glucose tolerance test performed at mid-gestation.

METHODS

In this prospective cohort study, 1087 pregnant women received a broad risk evaluation and laboratory examination at early gestation and were later classified as normal glucose tolerant (NGT), as having isolated fasting hyperglycaemia (GDM-IFH), isolated post-load hyperglycaemia (GDM-IPH) or combined hyperglycaemia (GDM-CH) according to oral glucose tolerance test results. Participants were followed up until delivery to assess data on pharmacotherapy and pregnancy outcomes.

RESULTS

Women affected by elevated fasting and post-load glucose concentrations (GDM-CH) showed adverse metabolic profiles already at beginning of pregnancy including a higher degree of insulin resistance as compared to women with normal glucose tolerance and those with isolated defects (especially GDM-IPH). The GDM-IPH subgroup had lower body mass index at early gestation and required glucose-lowering medications less often (28.9%) as compared to GDM-IFH (47.8%, P = .019) and GDM-CH (54.5%, P = .005). No differences were observed in pregnancy outcome data.

CONCLUSIONS

Women with fasting hyperglycaemia, especially those with combined hyperglycaemia, showed an unfavourable metabolic phenotype already at early gestation. Therefore, categorization based on abnormal oral glucose tolerance test values provides a practicable basis for clinical risk stratification.

Association between maternal triglycerides and disturbed glucose metabolism in pregnancy

AIMS

Dyslipidemia in pregnancy is associated with adverse pregnancy outcomes as elevated triglycerides might be considered as a risk factor for hyperglycemia and gestational diabetes. As only a few studies have addressed the association between maternal triglycerides and glucose metabolism, we aimed to explore the pathophysiologic associations of moderate hypertriglyceridemia and maternal glucose metabolism in pregnancy.

METHODS

Sixty-seven pregnant women received a detailed metabolic characterization at 12+0-22+6 weeks of gestation by an extended 2h-75g OGTT (oral glucose tolerance test); with measurements of glucose, insulin and C-peptide at fasting and every 30 min after ingestion and assessment of triglycerides at fasting state. All examinations were repeated at 24+0-27+6 weeks of gestation.

RESULTS

Elevated triglycerides in early gestation were associated with insulin resistance and β-cell dysfunction. Mean glucose concentrations during the OGTT in early pregnancy were already higher in women with hypertriglyceridemia as compared to women with triglycerides in the normal range. A higher degree of insulin resistance and increased OGTT glucose levels were also observed when metabolic assessments were repeated between 24 and 28 weeks of gestation. Of note, elevated triglycerides at early gestation were associated with development of gestational diabetes by logistic regression (odds ratio: 1.16, 95%CI: 1.03-1.34, p=0.022 for an increase of 10 mg/dl).

CONCLUSIONS

Hypertriglyceridemia at the start of pregnancy is closely related to impaired insulin action and β-cell function. Women with hypertriglyceridemia have higher mean glucose levels in early- and mid-gestation. Pregnant women with elevated triglycerides in early pregnancy are at increased risk of developing gestational diabetes.

Early Assessment of the Risk for Gestational Diabetes Mellitus: Can Fasting Parameters of Glucose Metabolism Contribute to Risk Prediction?

BACKGROUND

An early identification of the risk groups might be beneficial in reducing morbidities in patients with gestational diabetes mellitus (GDM). Therefore, this study aimed to assess the biochemical predictors of glycemic conditions, in addition to fasting indices of glucose disposal, to predict the development of GDM in later stage and the need of glucose-lowering medication.

METHODS

A total of 574 pregnant females (103 with GDM and 471 with normal glucose tolerance [NGT]) were included. A metabolic characterization was performed before 15⁺⁶ weeks of gestation by assessing fasting plasma glucose (FPG), fasting insulin (FI), fasting C-peptide (FCP), and glycosylated hemoglobin (HbA1c). Thereafter, the patients were followed-up until the delivery.

RESULTS

Females with NGT had lower levels of FPG, FI, FCP, or HbA1c at the early stage of pregnancy, and therefore, showed an improved insulin action as compared to that in females who developed GDM. Higher fasting levels of FPG and FCP were associated with a higher risk of developing GDM. Moreover, the predictive accuracy of this metabolic profiling was also good to distinguish the patients who required glucose-lowering medications. Indices of glucose disposal based on C-peptide improved the predictive accuracy compared to that based on insulin. A modified quantitative insulin sensitivity check index (QUICKIc) showed the best differentiation in terms of predicting GDM (area under the receiver operating characteristics curve [ROC-AUC], 72.1%) or need for pharmacotherapy (ROC-AUC, 83.7%).

CONCLUSION

Fasting measurements of glucose and C-peptide as well as the surrogate indices of glycemic condition could be used for stratifying pregnant females with higher risk of GDM at the beginning of pregnancy.