Gestational retinal microvasculature and the risk of 5 year postpartum abnormal glucose metabolism

Uteroplacental microvascular remodeling in health and disease

The microvascular system is essential for delivering oxygen and nutrients to tissues while removing metabolic waste. During pregnancy, the uteroplacental microvascular system undergoes extensive remodeling to meet the increased demands of the fetus. Key adaptations include vessel dilation and increases in vascular volume, density, and permeability, all of which ensure adequate placental perfusion while maintaining stable maternal blood pressure. Structural and functional abnormalities in the uteroplacental microvasculature are associated with various gestational complications, posing both immediate and long-term risks to the health of both mother and infant. In this review, we describe the changes in uteroplacental microvessels during pregnancy, discuss the pathogenic mechanisms underlying diseases such as preeclampsia, fetal growth restriction, and gestational diabetes, and summarize current clinical and research approaches for monitoring microvascular health. We also provide an update on research models for gestational microvascular complications and explore solutions to several unresolved challenges. With advancements in research techniques, we anticipate significant progress in understanding and managing these diseases, ultimately leading to new therapeutic strategies to improve maternal and fetal health.

Optical Coherence Tomography Angiography Evaluation of Retinochoroidal Microvascular Circulation Differences in Pregnant Women with Pregestational and Gestational Diabetes Mellitus

PURPOSE

In this study, the changes in microvascular circulation caused by pregestational and gestational diabetes were observed, without focusing on retinal findings, to reveal the effect of diabetes regulation.

METHODS

A total of 135 subjects were included: 30 with gestational diabetes (GDM), 30 pregestational diabetes (PGDM), 30 healthy pregnant normoglycemic subjects, and 45 healthy non-pregnant subjects. All subjects were examined by optical coherence tomography (OCT) and angiography. The retina, retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), choroidal thickness (CT), superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC), vascular density (VD), and foveal avascular zone (FAZ) areas were measured.

RESULTS

The foveal VD of SCP and DCP was significantly lower in the PGDM and GDM groups compared to the control groups (p:0.006 and p:0.001, respectively). CC VD was significantly higher in all pregnant groups compared to non-pregnant controls (p<0.001). The choroidal thickness values were highest in the healthy pregnant group and lowest in the PGDM group. There was no significant difference in FAZ area, retina, RNFL and GCL thickness between the groups. In the PGDM group, a negative correlation was observed between the FAZ area and the HbA1c level (r:- 0.417, p:0.043).

CONCLUSION

There was a decrease in vascular density in pregnant women with diabetes compared to healthy pregnant women and controls. In the pregnant group with PGDM, a narrowing of the FAZ area was observed with increasing worsening of diabetes control. Diabetes type and glycemic control could influence the microvascular changes even in the absence of clinical or retinal findings.

Retinal Vascular Imaging Application in Women's Reproductive Health: Clinical Implications and Future Directions

Over the past two decades, population-based studies employing semiautomatic computer-assisted programs have uncovered associations between retinal microvascular features and various systemic conditions. As the recognition of retinal imaging in cardiometabolic health grows, there is increasing evidence supporting its application in women's health, particularly during the reproductive age. This review aims to summarize the indications of retinal imaging in women's health and intergenerational health, where suboptimal retinal imaging has been found to mirror pathological systemic changes, such as suboptimal hemodynamic circulation, inflammation, endothelial dysfunction, oxidative stress, and hypoxia in vivo. Findings from Singapore Growing Up in Singapore Towards Healthy Outcomes and Singapore Preconception Study of Long-Term Maternal and Child Outcomes cohorts have reported serial changes in retinal conventional microvascular features (e.g., retinal arteriolar narrowing, retinal venular widening) and retinal geometric microvascular features (e.g., sparse fractal dimension, enlarged branching angle, and increased curvature tortuosity) during the preconception and antenatal phases. These morphological abnormalities were found to be related to female fertility, maternal antenatal health conditions, postnatal maternal cardiometabolic health, and intergenerational health in the fetus. Given the compelling evidence of the ability to detect microvascular changes through noninvasive methods at an early stage, retinal imaging holds the potential to facilitate timely interventions, mitigate the progression of complications, and prevent adverse pregnancy outcomes. Looking ahead, the convergence of artificial intelligence and advanced imaging techniques heralds a promising era in women's health research and clinical practice.

Preconception maternal retinal venular widening and steeper resistance increments in the utero-fetoplacental circulation in pregnancy

We investigated the relationship of preconception maternal retinal vasculature and utero-fetoplacental circulation in ensuing pregnancy. Embedded in a hospital-based, prospective preconception cohort, 396 women with a singleton live birth were included for analysis. We assessed retinal vascular caliber during preconception phase and retrieved ultrasonogram results documenting utero-fetoplacental circulatory indices using Doppler ultrasonography and documented them at 18-21 weeks, 24-28 weeks, and 32-34 weeks where available. We performed a modified Poisson regression to estimate the relative risk of utero-fetoplacental abnormalities, adjusting for major confounders including pre-pregnancy and blood pressure. Per 10 μm increment in maternal preconception retinal venules was associated with over two-fold risks in developing notching (Relative risk [RR]: 2.84; 95% confidence interval [CI]: 1.79, 4.81) and ≥95th percentile umbilical artery pulsatility index (2.36; 1.72, 3.23) during mid-to-late pregnancy, respectively. Women with preconception retinal venular widening tended to demonstrate steeper resistance increments in both maternal uterine arteries and fetal umbilical arteries during mid-to-late pregnancy.

Polish Women Have Moderate Knowledge of Gestational Diabetes Mellitus and Breastfeeding Benefits

Gestational diabetes mellitus (GDM) is a multifaceted disease and is associated with complications for newborns and mothers. The aim of the study was to assess Polish women’s knowledge concerning GDM and their attitude to breastfeeding. As a research tool, an anonymous online survey that included 33 questions, grouped into three main sections—sociodemographic and obstetric variables, risk factors for GDM and neonatal adverse outcomes, and knowledge about breastfeeding—was used and administered online. A total of 410 women aged from 18 to 45 participated in this study. Based on the survey, it was demonstrated that the women had moderate knowledge concerning the maternal risk factors and adverse neonatal outcomes associated with GDM and, additionally, the short- and long-term effects of breastfeeding. Significantly deeper knowledge about GDM, including breastfeeding by GDM mothers, was observed among hyperglycemic mothers in comparison to normoglycemic mothers. However, knowledge concerning the health benefits of breastfeeding was not related to the mothers’ glycemic status. In conclusion, educational programs must include pre-pregnancy education of women and place emphasis on explaining the mechanism of development of GDM and the transformation of GDM to type 2 diabetes. This is crucial for changing the public’s perception of GDM as a temporary, reversible clinical entity.

A deep-learning system for the assessment of cardiovascular disease risk via the measurement of retinal-vessel calibre

Retinal blood vessels provide information on the risk of cardiovascular disease (CVD). Here, we report the development and validation of deep-learning models for the automated measurement of retinal-vessel calibre in retinal photographs, using diverse multiethnic multicountry datasets that comprise more than 70,000 images. Retinal-vessel calibre measured by the models and by expert human graders showed high agreement, with overall intraclass correlation coefficients of between 0.82 and 0.95. The models performed comparably to or better than expert graders in associations between measurements of retinal-vessel calibre and CVD risk factors, including blood pressure, body-mass index, total cholesterol and glycated-haemoglobin levels. In retrospectively measured prospective datasets from a population-based study, baseline measurements performed by the deep-learning system were associated with incident CVD. Our findings motivate the development of clinically applicable explainable end-to-end deep-learning systems for the prediction of CVD on the basis of the features of retinal vessels in retinal photographs.

Exploring abnormal glucose metabolism in pregnancy among Australian Chinese migrants

OBJECTIVE

Gestational diabetes mellitus (GDM) is a metabolic disorder of pregnancy that is increasingly prevalent among Chinese women. Few studies have examined whether the migration status of Chinese women contributes to the risks of developing GDM during pregnancy.

RESEARCH DESIGN AND METHODS

In this observational, cross-sectional and hospital-based study, we examined the prevalence of GDM and glycemic levels at oral glucose tolerance test (OGTT) among 491 Australian Chinese migrants (n=491) and native Chinese (n=1000). We defined GDM using the International Association of Diabetes and Pregnancy Study Groups guidelines. We collected data on maternal age, body mass index (BMI) and gestational age (GA) at booking and GA at delivery from medical records. We used multiple logistic and linear regression models to calculate the OR of having GDM and mean differences in glycemic levels in Australian Chinese migrants, relative to native Chinese.

RESULTS

Age-at-booking and BMI-at-booking adjusted GDM prevalence was significantly higher in Australian Chinese migrants than native Chinese (19.7% vs 14.6%; p=0.01). After adjusting for age, BMI at booking and GA at booking, fasting glucose levels were significantly lower (β -0.08 mmol/L; 95% CI -0.14 to 0.02), while 2-hour glucose levels were significantly higher (0.22 mmol/L; 0.02 to 0.43) in Australian Chinese immigrants than native Chinese.

CONCLUSIONS

Migration status may be a marker for abnormal glucose metabolism during pregnancy among Australian Chinese migrants, possibly due to socio-economic disadvantages and lifestyle changes associated with migration.

Relationship between Size of the Foveal Avascular Zone and Carbohydrate Metabolic Disorders during Pregnancy

Aim

To determine whether the area of the foveal avascular zone (FAZ), as a morphological indicator of the microcirculation of the perifoveal capillary network, changes in the carbohydrate metabolism disorders during pregnancy (the gestational age of patients with gestational diabetes mellitus (GDM) and preexisting diabetes (PexD)).

Methods

Ten normal individuals and 41 eyes of 41 patients, 28 with GDM and 13 with PexD, were studied. A 3 × 3 mm area of the FAZ of the superficial capillary plexus layer (SCP) and the deep capillary plexus layer (DCP) was determined by optical coherence tomography angiography (OCTA; RS-3000 Advance, NIDEK). The significance of the correlation between the size of the FAZ and the weeks of pregnancy was determined.

Results

The area of the FAZ of the SCP was 0.38 ± 0.11 mm² (normal eyes), 0.41 ± 0.16 mm² (GDM), and 0.43 ± 0.10 mm² (PexD). The area of the FAZ of the DCP was 0.78 ± 0.23 mm² (normal eyes), 0.69 ± 0.16 mm² (GDM), and 0.79 ± 0.25 mm² (PexD). No significant difference in the FAZ sizes was observed between the groups. The average number of weeks of pregnancy was 24.1 ± 8.2 weeks in the eyes with GDM and 23.3 ± 11.4 weeks in the eyes with PexD (P > 0.05). Significant correlations were found between the size of the FAZ of the SCP and the number of weeks (r = 0.37, P=0.04 for GDM, and r = 0.49, P=0.04 for PexD, Spearman's rank-order correlation coefficient).

Conclusions

For GDM and PexD under established glycemic control, the area of the FAZ is not affected, but vascular changes occurred at the early phase of pregnancy.

Comparing Different Diagnostic Guidelines for Gestational Diabetes Mellitus in Relation to Birthweight in Sri Lankan Women

Introduction: While the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria is widely adopted in many countries, clinicians have questioned the applicability of these diagnostic thresholds for different races/ethnicities. We first compared the prevalence of gestational diabetes mellitus (GDM) diagnosed with different criteria including IADPSG, World Health Organization (WHO) 1999 and Sri Lankan national guidelines, and subsequently related individual guidelines-specific GDM prevalence to offspring birthweight in Sri Lanka. Materials and Methods: We retrospectively collected data on singleton pregnancies (n = 795) from two tertiary hospitals in Sri Lanka. We applied three diagnostic guidelines to define GDM, namely IADPSG criteria, the Sri Lankan national and WHO 1999 guidelines. We calculated the age- and first booking BMI-adjusted prevalence rates of GDM and assessed the association of GDM (using each guideline) with birthweight. Results: The age- and first booking BMI-adjusted GDM prevalence rates were 31.2, 28.0, and 13.1% for IADPSG criteria, Sri Lankan national and WHO 1999 guidelines, respectively. The IADPSG criteria identified 90 distinctive GDM cases at a lower cut-off of fasting glucose (from 5.1 to 5.5 mmol/L) while Sri Lankan national guideline identified 15 distinctive GDM cases at a lower cut-off for 2-h glucose (from 7.8 to 8.4 mmol/L). After adjusting for age, GDM diagnosed by IADPSG criteria was associated with higher birthweight [90.8 g, 95% CI: 10.8, 170.9], while the associations for GDM diagnosed either by Sri Lankan national or WHO 1999 guidelines were not significant. Conclusion: Adopting the IADPSG criteria for diagnosing GDM may be important in Sri Lankan pregnant population.