Effects Of Gestational Diabetes On Fetal Cardiac Structure And Function

Objective: Cardiac function of fetuses, neonates, and 6-month-old infants of mothers with gestational diabetes are assessed through the application of M-mode echocardiogram, and potential mechanisms of change are preliminarily discussed, providing new perspectives and references for noticing and observing cardiac changes of fetuses of mothers with gestational diabetes.Methods:1 Experimental group: 40 pregnant women aged between 20 and 40 with pregnancies of 24-28 weeks were recruited, the average age being 28.2 ±2.4. Another 40 cases of normal singleton pregnancies of 24-28 weeks within the corresponding period were selected as the normal control group. A physician measured and obtained satisfactory M-mode annular displacement images, studied the subjects who had been divided into two groups, and conducted following-up interviews with subjects with neonates of less than 1 week and infants of 6 months.2 GE Voluson E8, color Doppler ultrasound diagnostic instrument, equipped with a 2~8MHz RAB4-8-D probe, as well as Philips IE33, color Doppler ultrasound diagnostic instrument, equipped with a 4-12 MHz S12-4 phased array probe and a 1~5MHz S5-1 probe were used. All the data and images collected have been measured and saved by the instruments’ software system.3 Image collection and parameter measurementOrdinary ultrasonography has been firstly performed to estimate gestational weeks; under fetal cardiac mode, fetal echocardiography has been carried out afterwards to examine fetal cardiac structure and function holistically;Two-dimensional ultrasound: Commonly-adopted ultrasonic cross sections includes four-chamber view, left and right ventricular outflow tracts, aortic arch view, and ductal arch view;M-mode echocardiogram: Under the guidance of two-dimensional ultrasound, inner diameters of heart and great vessels, and thickness of ventricular walls have been measured;Doppler echocardiogram: it contains spectral Doppler echocardiography i.e pulsed wave Doppler(PW) and continuous wave Doppler(CW), and color Doppler flowing imaging(CDFI), which is applied to assess the velocity, size, direction and other properties of blood flow.Mitral annular displacement(MAD) measurement: With the standard four-chamber view being presented, M-mode sampling line should position itself as vertically as possible to the joint of posterior leaflet and annulus and record the motion curve of mitral valve annulus at a baseline tracing speed of 75~150mm/s until clear images are obtained. Afterwards, the maximum displacement i.e. the vertical distance between systole and diastole should be calculated. The whole measurement process should be gone through consecutively for three cardiac cycles and a mean value should be calculated.Tricuspid annular displacement(TAD) measurement: With the standard four-chamber view being presented, the probe should be adjusted to direct cardiac apex forward or backward in order to have the maximum cross-section view of right ventricle. To use M-mode ultrasonography for TAD measurement, the sampling point should be positioned at the joint of anterior leaflet of tricuspid annulus and right ventricular free wall. During measurement the beam should be as vertically parallel to heart as possible to reduce the included angle in-between(angle<20o). The maximum distance between systole and diastole should be calculated during each cardiac cycle; the measurement process should be gone through consecutively for three cardiac cycles and a mean value should be calculated.4 After subjects’ deliveries, PHILIPS i E33, color ultrasound diagnostic instrument, has been used to check cardiac situation of the neonates and infants. Specifically, in order to observe changes of cardiac structure and function, inner diameters of heart and great vessels, and thickness of ventricular walls should be assessed by echocardiogram following common practices; blood flow velocity should be measured by CDFI and Doppler echocardiogram. MAD and TAD cross-sections should be measured as well. With the standard four-chamber view being presented, M-mode sampling line should position itself as vertically as possible to the joint of posterior leaflet and annulus, or at the joint of anterior leaflet of tricuspid annulus and right ventricular free wall, and record the motion curves of mitral valve and tricuspid valve at a baseline tracing speed of 75~150mm/s until clear images are obtained. Afterwards, the maximum displacements i.e. the vertical distance between systole and diastole of mitral valve and tricuspid valve should be calculated. The whole measurement process should be gone through consecutively for three cardiac cycles and a mean value should be calculated.Results:1 Compared with the normal control group, subjects with diabetes had higher values of fasting blood glucose(FBG) and 2-hour postprandial blood glucose(2h PBG), which is statistically significant(P<0.05).2 Fetuses from the diabetic group had higher values of BPD, FL, HC, AC, and HL than those from the normal control group, which is statistically significant(P<0.05).3 Interventricularseptal(IVS), left ventricular posterior wall(LVPW) and left ventricular mass(LVM) of fetuses from the diabetic group increased compared with those from the normal control group, which is statistically significant(P<0.05); TAD and MAD values of fetuses from the diabetic group was lower than those from the normal control group, which is statistically significant(P<0.05); cardiac transverse diameter, thoracic transverse diameter, left ventricular inner diameter, left atrial inner diameter, right ventricular inner diameter, right atrial inner diameter and pulmonary arterial inner diameter of fetuses from the diabetic group increased compared with those from the normal control group, however it does not show any statistically significant difference(P>0.05). Similarly, values of aortic inner diameter, oval foramen, arterial duct, left and right ventricular EF were lower than those from the normal control group, yet it is not statistically significant either(P>0.05).4 One-month-old neonates from the gestational diabetic group have also been compared to those from the normal control group. Specifically, left ventricular inner diameter, left atrial inner diameter, right ventricular inner diameter, right atrial inner diameter, IVS, LVPW and myocardial mass(MM) increased than those from the normal control group, which is statistically significant(P<0.05); TAD and MAD values were lower compared to those in the normal control group, which is also statistically significant(P<0.05); values of aortic inner diameter, pulmonary arterial inner diameter, LVEF, E, A, AV, PV and gender do not show any statistical significance(P>0.05).5 Echocardiograms of six-month-old infants from the gestational diabetic group have been compared with those of infants from the normal control group. To be more specific, values of multiple parameters including left ventricular inner diameter, left atrial inner diameter, right ventricular inner diameter, right atrial inner diameter, IVS, LVPW, aorta inner diameter, pulmonary arterial inner diameter, MM, LVEF, TAD, MAD, E, A, AV, and PV do not show any statistical significance(P>0.05).Conclusions:1 Values of ventricular wall thickening and left ventricular of fetuses from the gestational diabetic group mass have been evidently higher than those in the normal control group, which indicates that both parameters can adequately reflect gestational diabetes’ effects on left ventricles of fetuses of mothers with gestational diabetes.2 Two-dimensional ultrasound cannot sensitively notice cardiac impairment of fetuses of mothers with gestational diabetes.3 Measured MAD and TAD values of fetuses of mother with gestational diabetes have been lower than those in the normal control group, which indicates that parameters as MAD and TAD may help notice cardiac impairment of fetuses of mothers with gestational diabetes.4 From following-up interviews among subjects with one-week-old neonates and six-month-old infants, the changes posed by gestational diabetes on fetal cardiac structure and cardiac impairment can be gradually recovered.