Does a First-Degree Family History of Diabetes Impact Placental Maternal and Fetal Vascular Circulation and Inflammatory Response?

Nutrition and Metabolic Adaptations in Physiological and Complicated Pregnancy: Focus on Obesity and Gestational Diabetes

Pregnancy offers a window of opportunity to program the future health of both mothers and offspring. During gestation, women experience a series of physical and metabolic modifications and adaptations, which aim to protect the fetus development and are closely related to both pre-gestational nutritional status and gestational weight gain. Moreover, pre-gestational obesity represents a challenge of treatment, and nowadays there are new evidence as regard its management, especially the adequate weight gain. Recent evidence has highlighted the determinant role of nutritional status and maternal diet on both pregnancy outcomes and long-term risk of chronic diseases, through a transgenerational flow, conceptualized by the Development Origin of Health and Diseases (Dohad) theory. In this review we will analyse the physiological and endocrine adaptation in pregnancy, and the metabolic complications, thus the focal points for nutritional and therapeutic strategies that we must early implement, virtually before conception, to safeguard the health of both mother and progeny. We will summarize the current nutritional recommendations and the use of nutraceuticals in pregnancy, with a focus on the management of pregnancy complicated by obesity and hyperglycemia, assessing the most recent evidence about the effects of ante-natal nutrition on the long-term, on either maternal health or metabolic risk of the offspring.

Glycaemic status during pregnancy and longitudinal measures of fetal growth in a multi-racial US population: a prospective cohort study

BACKGROUND

The timepoint at which fetal growth begins to differ by maternal glycaemic status is not well understood. To address this lack of data, we examined gestational diabetes, impaired glucose tolerance, and early pregnancy glucose concentrations in relation to fetal growth trajectories.

METHODS

This cohort study included 2458 pregnant women from the NICHD Fetal Growth Studies-Singletons study, which took place between 2009 and 2013. Women were recruited from 12 clinical centres in the USA. Women aged 18-40 years without major chronic conditions when entering pregnancy were included and those with records of neither glucose screening test or glucose tolerance test were excluded from the study. Women were enrolled at gestational weeks 8-13 and randomly assigned to four ultrasonogram schedules (Group A; weeks 16, 24, 30, 34; Group B: weeks 18, 26, 31, 35, 39; Group C: weeks 20, 28, 32, 36; Group D: weeks 22, 29, 33, 37, 41) to capture weekly fetal growth. Gestational diabetes, impaired glucose tolerance, and normal glucose tolerance were defined by medical record review. Glucose was measured in a subsample of women at weeks 10-14. We modelled fetal growth trajectories using linear mixed models with cubic splines. This study is registered with ClinicalTrials.gov, NCT00912132.

FINDINGS

Of the 2458 women included in this study, 107 (4·4%) had gestational diabetes, 118 (4·8%) had impaired glucose tolerance, and 2020 (82·2%) had NGT. 213 women were excluded from the main analysis. The cohort with gestational diabetes was associated with a larger estimated fetal weight that started at week 20 and was significant at week 28-40 (at week 37: 3061 g [95% CI 2967-3164] for women with gestational diabetes vs 2943 g [2924-2962] for women with normal glucose tolerance, adjusted p=0·02). In addition, glucose levels at weeks 10-14 were positively associated with estimated fetal weight starting at week 23 and the association became significant at week 27 (at week 37: 3073 g [2983-3167] in the highest tertile vs 2853 g [2755-2955] in the lowest tertile, adjusted p=0·0009.

INTERPRETATION

Gestational diabetes was associated with a larger fetal size that started at week 20 and became significant at gestational week 28. Efforts to mitigate gestational diabetes-related fetal overgrowth should start before 24-28 gestational weeks, when gestational diabetes is typically screened for in the USA.

FUNDING

National Institutes of Health.

Insulin Treatment Is Associated With Improved Fetal Placental Vascular Circulation in Obese and Non-obese Women With Gestational Diabetes Mellitus

Objective: The present study was designed to investigate the impact of carbohydrate restriction and insulin treatment on placental maternal and fetal vascular circulation in obese and non-obese women with gestational diabetes mellitus (GDM). Design and methods: One Hundred Ninety-One women with GDM who gave birth and underwent a placental histopathological examination at Wolfson Medical Center, Israel, were included in the study: 122 women who were treated with carbohydrate/calorie restriction diet (Group 1) and 69 women who were treated with diet plus insulin (Group 2). Additionally, each group was divided into two subgroups according to pre-pregnancy BMI: non-obese and obese. Results: Maternal vascular malperfusion lesions did not differ significantly between groups. Vascular lesions related to fetal malperfusion were significantly lower in GDM women treated by insulin and diet compared to women with diet alone (p = 0.027). Among fetal malperfusion lesions, villous changes consistent with fetal thrombo-occlusive disease (FTOD) were significantly lower in women treated with diet plus insulin and lowest in GDM women with pre-pregnancy BMI < 30 kg/m² (p = 0.009). In the logistic regression analysis, insulin treatment was significantly associated with a decreased rate of villous changes consistent with FTOD (OR 0.97, 95% CI 0.12-0.80, p = 0.03). Prevalence of gestational hypertension was higher in obese women of both treatment groups (p = 0.024). Conclusion: Combination of obesity and GDM increased rate of FTOD and prevalence of gestational hypertension. Carbohydrate restriction diet plus insulin treatment was associated with improved fetal placental vascular circulation, especially in GDM women with pre-pregnancy BMI < 30 kg/m².

Placental Nutrient Transport in Gestational Diabetic Pregnancies

Maternal obesity during pregnancy is rising and is associated with increased risk of developing gestational diabetes mellitus (GDM), defined as glucose intolerance first diagnosed in pregnancy (1). Fetal growth is determined by the maternal nutrient supply and placental nutrient transfer capacity. GDM-complicated pregnancies are more likely to be complicated by fetal overgrowth or excess adipose deposition in utero. Infants born from GDM mothers have an increased risk of developing cardiovascular and metabolic disorders later in life. Diverse factors, such as ethnicity, age, fetal sex, clinical treatment for glycemic control, gestational weight gain, and body mass index among others, represent a challenge for studying underlying mechanisms in GDM subjects. Determining the individual roles of glucose intolerance, obesity, and other factors on placental function and fetal growth remains a challenge. This review provides an overview of changes in placental macronutrient transport observed in human pregnancies complicated by GDM. Improved knowledge and understanding of the alterations in placenta function that lead to pathological fetal growth will allow for development of new therapeutic interventions and treatments to improve pregnancy outcomes and lifelong health for the mother and her children.