Vascular phenotype at 35-37 weeks' gestation in women with gestational diabetes mellitus

Fetomaternal Doppler sonography for the prediction of perinatal outcome in term pregnancies complicated by gestational diabetes mellitus: does it have potential?

Purpose

Little is known about the benefit and interpretation of fetomaternal Doppler sonography in GDM for the prediction of an adverse perinatal outcome (APO). The aim of this study was to examine the performance of fetomaternal Doppler for APO prediction in pregnancies with GDM at term.

Materials and Methods

This is a retrospective cohort study of singleton, non-anomalous fetuses of women with GDM, who primarily had a vaginal delivery attempt. Study inclusion also required no other major fetomaternal abnormalities that make placental dysfunction likely. Data on fetomaternal Doppler sonography including umbilical artery pulsatility index (PI), middle cerebral artery (MCA) PI, cerebroplacental ratio (CPR), mean uterine artery PI, cerebro-placental-uterine ratio (CPUR) was collected from 37+0 weeks on. Multivariate logistic regression analyses were performed using maternal characteristics, neonatal characteristics, and Doppler ultrasound parameters as independent variables with CAPO as a binary outcome.

Results

A total of n=88 cases were included. Nulliparity (p=0.032) and CPUR (p=0.052) were independent predictors of CAPO. However, CPUR had borderline significance. All other Doppler indices were not independent predictors of CAPO. The ability of CPUR alone (AUC=0.65, 95% CI 0.51 to 0.80) to discriminate between GDM pregnancies with and without CAPO was poor.

Conclusion

This study shows that there is no significant clinical relationship between fetomaternal Doppler indices and CAPO among pregnancies with GDM. This raises the question regarding the extent to which fetomaternal Doppler indices, which reflect placental function, can be helpful for CAPO prediction in GDM pregnancies.

Arterial stiffness in gestational diabetes: Latest insights

Increased arterial stiffness is a known cardiovascular risk factor, associated with hypertension and acute coronary events. Gestational diabetes (GDM) is associated with the development of placental-mediated disorders and future cardiovascular morbidity, raising the possibility of an association with increased arterial stiffness (AS). Several studies have now investigated this association through the assessment of pulse wave velocity and augmentation index. In the current review, we present the latest evidence regarding the changes in arterial stiffness in pregnancies complicated by GDM, before the onset of clinical disease, during its course, and after its resolution. We also review the evidence that AS could influence the need for different treatments for GDM, and the impact that the treatments, and in particular, metformin, could have on arterial stiffness.

Association of maternal body mass index with hemodynamic and vascular alterations at 35-37 weeks' gestation

OBJECTIVE

Globally, one in four pregnant women is classified as overweight or obese, based on their prepregnancy body mass index (BMI). Obese pregnant women are at increased risk of adverse pregnancy outcomes and long-term cardiovascular disease that occurs earlier in life. This study aimed to assess maternal hemodynamic and vascular parameters at 35-37 weeks' gestation, to understand the alterations that may occur in association with increased maternal BMI and gestational weight gain, and to evaluate obesity-related pregnancy outcomes.

METHODS

This was a prospective observational study of 11 731 women with a singleton pregnancy attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation at King's College Hospital, London, UK, between December 2021 and June 2024. Women were categorized based on their BMI at 11-13 weeks' gestation, as normal weight (BMI, 18.5-24.9 kg/m2), overweight (BMI, 25.0-29.9 kg/m2) or obese (BMI, ≥ 30 kg/m2). We recorded details regarding maternal demographic characteristics and medical history, used Doppler ultrasound to assess the uterine artery pulsatility index (UtA-PI) (as a marker for uteroplacental perfusion) and ophthalmic artery peak systolic velocity (PSV) ratio (as a marker for small vessel peripheral circulation), and measured carotid-to-femoral pulse-wave velocity, augmentation index (as direct and indirect markers of aortic stiffness, respectively), cardiac output, total peripheral resistance (TPR), and central systolic and diastolic blood pressure. Multivariable analysis was performed to examine the relationship of BMI and gestational weight gain with hemodynamic and vascular measures, adjusting for maternal demographics, medical history, pregnancy characteristics and pregnancy outcomes (including pre-eclampsia and gestational diabetes mellitus).

RESULTS

Overweight and obese women were more often of black ethnicity, and had higher central systolic and diastolic blood pressure, cardiac output, aortic stiffness and UtA-PI, compared with normal-weight women. There was no significant difference between overweight or obese women and normal-weight women with regard to TPR and ophthalmic artery PSV ratio. On multivariable analysis, increasing BMI at 11-13 weeks and gestational weight gain between 11-13 weeks and 35-37 weeks were independently associated with increases in all cardiovascular indices (including ophthalmic artery PSV ratio), apart from TPR.

CONCLUSIONS

Women with a high BMI in early pregnancy vs normal-weight women, and those with higher gestational weight gain, had worse maternal hemodynamic and vascular indices at 35-37 weeks' gestation, independent of baseline and pregnancy characteristics. Our findings support the notion that optimization of prepregnancy weight and gestational weight gain may improve maternal hemodynamics and vascular function during pregnancy, and therefore may improve pregnancy outcomes. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Do maternal haemodynamics have a causal influence on treatment for gestational diabetes?

BACKGROUND

Arterial stiffening is believed to contribute to the worsening of insulin resistance, and factors which are associated with needing pharmacological treatment of gestational diabetes (GDM), such as maternal obesity or advanced age, are associated with impaired cardiovascular adaptation to pregnancy. In this observational study, we aimed to investigate causal relationships between maternal haemodynamics and treatment requirement amongst women with GDM.

METHODS

We assessed maternal haemodynamics in women with GDM, comparing those who remained on dietary treatment with those who required pharmacological management. Maternal haemodynamics were assessed using the Arteriograph® (TensioMed Ltd, Budapest, Hungary) and the NICOM® non-invasive bio-reactance method (Cheetah Medical, Portland, Oregon, USA). A graphical causal inference technique was used for statistical analysis.

RESULTS

120 women with GDM were included in the analysis. Maternal booking BMI was identified as having a causative influence on treatment requirement, with each unit increase in BMI increasing the odds of needing metformin and/or insulin therapy by 12% [OR 1.12 (1.02 - 1.22)]. The raw values of maternal heart rate (87.6 ± 11.7 vs. 92.9 ± 11.90 bpm, p = 0.014) and PWV (7.8 ± 1.04 vs. 8.4 ± 1.61 m/s, p = 0.029) were both significantly higher amongst the women requiring pharmacological management, though these relationships did not remain significant in causal logistic regression.

CONCLUSIONS

Maternal BMI at booking has a causal, rather than simply associational, relationship on the need for pharmacological treatment of GDM. No significant causal relationships were found between maternal haemodynamics and the need for pharmacological treatment.

Maternal vascular indices and hemodynamic parameters at 36 weeks' gestation in gestational and pre-existing diabetes mellitus

OBJECTIVE

To compare maternal vascular indices and hemodynamic parameters at 35-37 weeks' gestation in pregnancies complicated by gestational diabetes mellitus (GDM), those with pre-existing diabetes mellitus (DM) and those without GDM or pre-existing DM.

METHODS

This was a prospective observational study in women with a singleton pregnancy attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks' gestation. The visit included recording of maternal demographic characteristics and medical history, and measurement of vascular indices and hemodynamic parameters using a non-invasive operator-independent device. These included carotid-to-femoral pulse-wave velocity, augmentation index, cardiac output, stroke volume, central systolic and diastolic blood pressure, total peripheral resistance and heart rate. The values in the GDM and pre-existing DM groups were compared to those in the unaffected group.

RESULTS

We examined 6746 women, of whom 396 were excluded because they had chronic hypertension or developed pre-eclampsia or gestational hypertension. The study population of 6350 pregnancies contained 99 (1.6%) with pre-existing Type-I or Type-II DM and 617 (9.7%) that developed GDM, including 261 (42.3%) that were treated with diet alone, 239 (38.7%) treated with metformin alone and 117 (19.0%) treated with insulin with or without metformin. Among women with GDM and those with pre-existing DM, compared to those without GDM or pre-existing DM, there was a higher median cardiac output and heart rate, central systolic and diastolic blood pressure and pulse-wave velocity, but there was no significant difference in stroke volume or total peripheral resistance. There were no significant differences within the GDM group according to treatment type, except for higher heart rate in women treated with metformin alone compared to the group treated with diet alone.

CONCLUSION

Women with GDM and those with pre-existing DM have evidence of early vascular disease in the third trimester, and this may contribute to their increased long-term cardiovascular risk. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Does treatment modality affect measures of arterial stiffness in women with gestational diabetes?

OBJECTIVE

To investigate whether arterial stiffness (AS) differs between healthy women and women with gestational diabetes mellitus (GDM) managed by different treatment modalities.

METHODS

This was a prospective longitudinal cohort study comparing AS in pregnancies complicated by GDM and low-risk controls. AS was assessed by recording aortic pulse-wave velocity (AoPWV), brachial augmentation index (BrAIx) and aortic augmentation index (AoAIx) using the Arteriograph® at four gestational-age windows: 24 + 0 to 27 + 6 weeks (W1); 28 + 0 to 31 + 6 weeks (W2); 32 + 0 to 35 + 6 weeks (W3) and ≥ 36 + 0 weeks (W4). Women with GDM were considered both as a single group and as subgroups stratified by treatment modality. Data were analyzed using a linear mixed model on each AS variable (log-transformed) with group, gestational-age window, maternal age, ethnicity, parity, body mass index, mean arterial pressure and heart rate as fixed effects and individual as a random effect. We compared the group means including relevant contrasts and adjusted the P-values using Bonferroni correction.

RESULTS

The study population comprised 155 low-risk controls and 127 women with GDM, of whom 59 were treated with dietary intervention, 47 were treated with metformin only and 21 were treated with metformin + insulin. The two-way interaction term of study group and gestational age was significant for BrAIx and AoAIx (P < 0.001), but there was no evidence that mean AoPWV was different between the study groups (P = 0.729). Women in the control group demonstrated significantly lower BrAIx and AoAIx compared with the combined GDM group at W1-W3, but not at W4. The mean difference in log-transformed BrAIx was -0.37 (95% CI, -0.52 to -0.22), -0.23 (95% CI, -0.35 to -0.12) and -0.29 (95% CI, -0.40 to -0.18) at W1, W2 and W3, respectively. The mean difference in log-transformed AoAIx was -0.49 (95% CI, -0.69 to -0.30), -0.32 (95% CI, -0.47 to -0.18) and -0.38 (95% CI -0.52 to -0.24) at W1, W2 and W3, respectively. Similarly, women in the control group also demonstrated significantly lower BrAIx and AoAIx compared with each of the GDM treatment subgroups (diet, metformin only and metformin + insulin) at W1-W3. The increase in mean BrAIx and AoAIx seen between W2 and W3 in women with GDM treated with dietary management was attenuated in the metformin-only and metformin + insulin groups. However, the mean differences in BrAIx and AoAIx between these treatment groups were not statistically significant at any gestational-age window.

CONCLUSIONS

Pregnancies complicated by GDM demonstrate significantly higher AS compared with low-risk pregnancies regardless of treatment modality. Our data provide the basis for further investigation into the association of metformin therapy with changes in AS and risk of placenta-mediated diseases. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.