Glucose control during pregnancy in patients with type 1 diabetes correlates with fetal hemodynamics: a prospective longitudinal study

BACKGROUND

Maternal diabetes adversely affects fetal cardiovascular system development. Previous studies have reported that the fetuses of mothers with diabetes exhibit both structural and functional changes; nevertheless, prior studies have not examined the association between glucose control and fetal cardiac morphology and performance. Thus, the objective was to determine the association between fetal cardiac morphology and function and maternal glucose control in type 1 diabetes and to compare the differences in measured cardiac parameters between the fetuses of mothers with diabetes and healthy controls.

METHODS

In this prospective, longitudinal case-control study - including 62 pregnant women with type 1 diabetes mellitus and 30 healthy pregnant women - fetal cardiac assessment using B-mode, M-mode, and spectral pulsed-wave Doppler was performed in the second and third trimesters. In women with T1DM, glycated hemoglobin and data obtained from glucose sensors - including the percentage of time in, below, and above the range (TIR, TBR, and TAR, respectively), and coefficient of variation (CV) - were analyzed across three time periods: the last menstrual period to 13 (V1), 14-22 (V2), and 23-32 weeks (V3) of gestation. Fetal cardiac indices were compared between groups, and the correlation between glucose control and fetal cardiac indices was assessed.

RESULTS

At 28-32 weeks, the fetuses of women with T1DM exhibited increased left ventricular end-diastolic length, relative interventricular septum thickness, right ventricular cardiac output, and pulmonary valve peak systolic velocity compared with healthy controls. At 18-22 weeks, pulmonary and aortic valve diameters, left and right ventricular stroke volumes, and left cardiac output inversely correlated with the CV and glycated hemoglobin levels at V1 and V2. Furthermore, at 28-32 weeks, pulmonary and aortic valve diameters, left ventricular stroke volume, cardiac output, and right/left atrioventricular valve ratio inversely correlated with the TBR at V1, V2, and V3. Moreover, diastolic functional parameters correlated with the TAR and glycated hemoglobin levels, particularly after the first trimester.

CONCLUSION

In women with T1DM, maternal hyperglycemia during pregnancy correlates with fetal diastolic function, whereas glucose variability and hypoglycemia inversely correlate with fetal left ventricular systolic function in the second and third trimesters.

Shunt rate of ductus arteriosus and ductus venosus in middle and late fetuses and their application value in the evaluation of fetal growth restriction

Objective

To explore the Shunt rate of ductus arteriosus (DA) and ductus venosus (DV) in middle and late fetuses and their application value in the evaluation of fetal growth restriction (FGR).

Methods

In this retrospective observational study, we reviewed the clinical data of the patients who admitted to the Second Affiliated Hospital of Wenzhou Medical University from September 10, 2017 to November 27, 2018, and finally included 44 normal women at 28-31 weeks of pregnancy (Normal group) and 15 pregnant women with fetal growth restriction (FGR) within 28-31 weeks of gestation (FGR group). We measured blood flows of the DA (QDA), pulmonary artery (QPA), DV (QDV), and umbilical vein (QUV) and the shunt rates of the DA and DV (QDA/QPA and QDV/QUV, respectively) in all fetuses. We compared the mean variables between groups using the Normal group means as the normal reference values for analysis.

Results

DA shunt rate was linearly and positively correlated with gestational age (Y=1.455X+2.787; r=0.767, P<0.01), while the DV shunt rate was linearly and negatively correlated with gestational age (Y=-2.791X+126.885; r=0.761, P<0.01). The DA shunt rates (QDA/QPA) of fetuses in the normal were higher than those in the FGR groups, but the differences between the two groups were not statistically significant (P > 0.05). The DV shunt rates (QDV/QUV) of fetuses in the normal were significantly lower than those in the FGR groups (P < 0.05). The DV shunt rates in the FGR group were significantly higher than those in the normal group with differences being statistically significant at 30-30+6 and 31-31+6 gestational weeks (P < 0.05) The receiver operating characteristic curve (ROC curve) showed that the higher the shunt rate, the worse the birth outcome of a fetus with FGR.

Conclusions

The DV shunt rate in middle- and late-stage fetuses can predict the fetal birth outcome, and the higher the shunt ratio, the worse the birth outcome of FGR fetuses.

Understanding Fetal Hemodynamics Using Cardiovascular Magnetic Resonance Imaging

Human fetal circulatory physiology has been investigated extensively using grey-scale ultrasound, which provides excellent visualization of cardiac anatomy and function, while velocity profiles in the heart and vessels can be interrogated using Doppler. Measures of cerebral and placental vascular resistance, as well as indirect measures of intracardiac pressure obtained from the velocity waveform in the ductus venosus are routinely used to guide the management of fetal cardiovascular and placental disease. However, the characterization of some key elements of cardiovascular physiology such as vessel blood flow and the oxygen content of blood in the arteries and veins, as well as fetal oxygen delivery and consumption are not readily measured using ultrasound. To study these parameters, we have historically relied on data obtained using invasive measurements made in animal models, which are not equivalent to the human in every respect. Over recent years, a number of technical advances have been made that have allowed us to examine the human fetal circulatory system using cardiovascular magnetic resonance (CMR). The combination of vessel blood flow measurements made using cine phase contrast magnetic resonance imaging and vessel blood oxygen saturation and hematocrit measurements made using T1 and T2 mapping have enabled us to emulate those classic fetal sheep experiments defining the distribution of blood flow and oxygen transport across the fetal circulation in the human fetus. In addition, we have applied these techniques to study the relationship between abnormal fetal cardiovascular physiology and fetal development in the setting of congenital heart disease and placental insufficiency. CMR has become an important diagnostic tool in the assessment of cardiovascular physiology in the setting of postnatal cardiovascular disease, and is now being applied to the fetus to enhance our understanding of normal and abnormal fetal circulatory physiology and its impact on fetal well-being.

Mathematical simulation of Doppler changes in late-onset smallness; progression patterns of cerebral and umbilical anomalies define two types of late-onset fetal growth restriction

OBJECTIVE

To evaluate the progression of Doppler abnormalities in fetuses with late-onset fetal smallness (SGA) that become growth restricted (FGR).

METHODS

524 Doppler examinations of the umbilical and cerebral arteries systems, belonging to 442 late-onset SGA fetuses after week 34, were studied, evaluating by means of the statistical difference with the respective abnormal centiles, the pattern of progression into abnormal Doppler values and the distribution and cumulative sum of Doppler anomalies according to the interval to delivery.

RESULTS

Only one third (33.5%, N = 148) of late-onset SGA fetuses presented Doppler anomalies, suggesting that most were of constitutional origin. The most frequent progression pattern into abnormal Doppler (N = 127, 85.81%) was that in which only one system (umbilical or cerebral) became abnormal. Half of fetuses debuted with abnormal umbilical flow (52%, N = 77) and half with cerebral anomalies (47.97%, N = 71), which were more likely to appear later and at shorter intervals to delivery (p = .007). These progression patters defined two varieties of late-onset FGR (type I and II) with similar outcome but different birth weight centiles (BW centile = 2.51, SD 2.91 versus 3.97, SD 3.17, p < .01).

CONCLUSION

Two thirds of late-onset fetal smallness occurs without hemodynamic changes. In half of the remaining cases an initial cerebral vasodilation defines a group of fetuses with similar outcome but higher BW centile.

Application of the INTERGROWTH-21st chart compared to customized growth charts in fetuses with left heart obstruction: late trimester biometry, cerebroplacental hemodynamics and perinatal outcome

PURPOSE

Birth weight (BW) is crucial for surgical outcome in children with left heart obstruction (LHO). Head circumference (HC) is believed to correlate with the neurocognitive outcome in LHO. Our aim was to investigate the application of international standardized growth charts from the INTERGROWTH-21st project in comparison to customized growth charts in fetal LHO.

METHODS

This is a retrospective cohort study consisting of 60 singleton pregnancies complicated by fetal LHO. For the z score calculation of estimated fetal weight (EFW) and biometric parameters, the INTERGROWTH-21st calculator was used as well as algorithms of customized growth charts. Antenatal measurements were compared to newborn biometry and the association with fetal Doppler results (MCA PI: middle cerebral artery pulsatility index and CPR: cerebroplacental ratio) was examined. Furthermore, the ability of each antenatal chart to predict adverse perinatal outcome was evaluated.

RESULTS

At a mean gestational age of 37 weeks, all assessment charts showed significantly smaller mean values for antenatal head circumference (HC) z scores. Highest detection rate for restricted HC growth antenatally was achieved with Hadlock charts. MCA PI and CPR were not associated with neonatal HC. A significant association was observed between EFW and 1-year survival, independent of the considered growth chart.

CONCLUSIONS

Growth chart independently, antenatal HC did tend to be smaller in LHO fetuses. A significant association was observed between EFW and 1-year survival rate. Prospective investigations in CHD fetuses should be carried out with internationally standardized growth charts to better examine their prognostic value in this high-risk population.

delayed cord clamping

Background

Recent studies suggest that delayed cord clamping (DCC) is advantageous for achieving hemodynamic stability and improving oxygenation compared to the immediate cord clamping (ICC) during fetal-to-neonatal transition yet there is no quantitative information on hemodynamics and respiration, particularly for pre-term babies and fetal disease states. Therefore, the objective of this study is to investigate the effects of ICC and DCC on hemodynamics and respiration of the newborn preterm infants in the presence of common vascular pathologies.

Methods

A computational lumped parameter model (LPM) of the placental and respiratory system of a fetus is developed to predict blood pressure, flow rates and oxygen saturation. Cardiovascular system at different gestational ages (GA) are modeled using scaling relations governing fetal growth with the LPM. Intrauterine growth restriction (GR), patent ductus arteriosus (PDA) and respiratory distress syndrome (RDS) were modeled for a newborn at 30 weeks GA. We also formulated a "severity index (SI)" which is a weighted measure of ICC vs. DCC based on the functional parameters derived from our model and existing neonatal disease scoring systems.

Results

Our results show that transitional hemodynamics is smoother in DCC compared to ICC for all GAs. Blood volume of the neonate increases by 10% for moderately preterm and term infants (32-40 wks) and by 15% for very and extremely preterm infants (22-30 wks) with DCC compared to ICC. DCC also improves the cardiac output and the arterial blood pressure by 17% in term (36-40 wks), by 18% in moderately preterm (32-36 wks), by 21% in very preterm (28-32 wks) and by 24% in extremely preterm (20-28 wks) births compared to the ICC. A decline in oxygen saturation is observed in ICC received infants by 20% compared to the DCC received ones. At 30 weeks GA, SI were calculated for healthy newborns (1.18), and newborns with GR (1.38), PDA (1.22) and RDS (1.2) templates.

Conclusion

Our results suggest that DCC provides superior hemodynamics and respiration at birth compared to ICC. This information will help preventing the complications associated with poor oxygenation arising in premature births and pre-screening the more critical babies in terms of their cardiovascular severity.

Transition from fetal to neonatal circulation: Modeling the effect of umbilical cord clamping

Hemodynamics of the fetal to neonatal transition are orchestrated through complex physiological changes and results in cardiovascular adaptation to the adult biventricular circulation. Clinical practice during this critical period can influence vital organ physiology for normal newborns, premature babies and congenital heart defect patients. Particularly, the timing of the cord clamping procedure, immediate (ICC) vs. delayed cord clamping (DCC), is hypothesized to be an important factor for the transitory fetal hemodynamics. The clinical need for a quantitative understanding of this physiology motivated the development of a lumped parameter model (LPM) of the fetal cardio-respiratory system covering the late-gestation to neonatal period. The LPM was validated with in vivo clinical data and then used to predict the effects of cord clamping procedures on hemodynamics and vital gases. Clinical time-dependent resistance functions to simulate the vascular changes were introduced. For DCC, placental transfusion (31.3 ml) increased neonatal blood volume by 11.7%. This increased blood volume is reflected in an increase in preload pressures by ~20% compared to ICC, which in turn increased the cardiac output (CO) by 20% (COICC=993 ml/min; CODCC=1197 ml/min). Our model accurately predicted dynamic flow patterns in vivo. DCC was shown to maintain oxygenation if the onset of pulmonary respiration was delayed or impaired. On the other hand, a significant 25% decrease in oxygen saturations was observed when applying ICC under the same physiological conditions. We conclude that DCC has a significant impact on newborn hemodynamics, mainly because of the improved blood volume and the sustained placental respiration.