The Effects Of High Risk Factors On Fetal Cardiac Structure And Function

The fetal cardiac function is different from the adult in many ways.With advancing gestation,ventricular compliance in increased,total peripheral resistance in decreased, fetal cardiac function tends to maturation.Under pathological condition,such as gestational diabetes mellitus(GDM),preeclampsia,fetal growth restriction(FGR),fetal cardiac structure and function may be impaired.Impaired fetal cardiac function may play an important role in perinatal mortality.Nowadays,study about fetal echocardiography puts emphasis on fetal heart malformation,and research about fetal cardiac function is underappreciated enough.In this research,combined two-dimension gray scale ultrasound,pulsed Doppler and tissue Doppler imaging(TDI),firstly,we studied normal fetal cardiac structure and function maturate with advancing gestation,correlation between fetal cardiac structure and function,correlation between tissue Doppler index and pulsed Doppler.Secondly,we investigated fetal myocardial changes and fetal cardiac function impaired of diabetic pregnancies.Whether or not there is reasonable glucose control,fetal cardiac structure and function were affected.We search more sensitive and effective parameters which may predict perinatal morbidity.We probed change of fetal cardiac function in preeclamptic pregnancies.Whether or not there is difference of fetal cardiac function between appropriate for gestational age(AGA) and fetal growth restriction(FGR).In this research,we also researched altered fetal cardiac function of FGR,and searched for valuable ultrasound parameter which may provide more clinical information about perinatal morbidity.Tissue Doppler imaging(TDI) represents an evolution of the Doppler technique that allows direct evaluation of myocardial velocities,is relatively independent of preload and heart rate.TDI could provide more detailed information of heart function which traditional ultrasound could not provide.Combined pulsed Doppler and TDI,we evaluated fetal cardiac structure and function in normal and high-risk pregnancies.Section 1.The assessment fetal cardiac structure and function in normal pregnanciesObjective:To explore the trend of fetal cardiac morphology and function in normal mid and third trimester.To assess the relationship between fetal cardiac structure and function and correlation of parameters between pulsed Doppler and tissue Doppler index(TDI).Methods:A prospective cross-sectional study of 215 low-risk pregnancies with a gestational age of 20-40 weeks constituted the reference population.The thickness in the middle of ventricular wall and interventricular septal,inner diameters of ventricular cavity,aorta and pulmonary artery were measured by gray ultrasound.Doppler waveforms were obtained across atrioventricular valves and semilunar.Umbilical artery (UA),the middle cerebral artery(MCA),ductal vein(DV) values were obtained.The diastolic and systolic velocity of ventricular free wall,interventricular septal,and atrioventricular were obtained by TDI.The correlation between the thicknesses of ventricular wall or IVS and velocity were assessed.The relation between TDI index and Doppler waveform across the atrioventricular were evaluated else.Results:There was positive correlation between thickness of ventricular wall or IVS and gestational age.The E/A ratio and the peak systolic velocity(PSV) across semilunar valves increased with advancing gestation.There were positive correlation between velocity of ventricular wall or IVS and gestational age.The systolic velocity of left ventricular wall and mitral annulus were lower than right ventricular wall and tricuspid annulus(P＜0.05).Yhe Em/Am of left ventricular wall and mitral annulus were bigger than right ventricular wall and tricuspid annulus(P＜0.05).There were positive correlation between systolic and diastolic velocity of ventricular wall and atrioventricular annulus and thickness of ventricular wall or IVS.The correlation between systolic and Em with thickness were more obvious than Am with thickness.The correlation existed between pulsed Doppler indexes and TDI indexes.Conclusions:The systolic and diastolic function of fetal heart became more mature with advancing gestation.There were positive relation between fetal cardiac structure and function.The correlation existed between TDI parameters and pulsed Doppler parameters. Section 2.Effects of gestational diabetes mellitus on fetal cardiac structure and functionObjective:To compare effects of different glycometabolic disturbance of diabetic mother on fetal cardiac structure and function.To evaluate different effects of mother metabolic control on fetal heart.To investigate valuable parameters in predicting perinatal morbidity.Methods:A cross-sectional prospective study of 31 type-1 or type-2 diabetic pregnancies, 137 GDM,19 gestational impaired glucose tolerance(GIGT) with a gestational age of 20-40 weeks.The parameters were the same as section 1.The fetuses in section 1 acted as normal control group.Results:1.Compared to GDM,the fetal thinner left diastolic ventricular wall was observed in maternal typeⅠorⅡdiabetes,P＜0.05.No difference was observed among three different types maternal glycometabolic disturbance on fetal cardiac function. MCA-PSV was most high in fetuses of GDM.2.Compared to fetuses of normal pregnancy, the thickness of ventricular wall and IVS were thicker in fetuses of well-controlled maternal GDM with a gestational age of 20-35.6 weeks,P＜0.05,systolic fraction of left ventricular and PSV of aorta were increased with a gestational age of 24-35.6 weeks, P＜0.05.Systolic fraction of right ventricular and PSV of pulmonary artery were increased with a gestational age of 28-40 weeks,P＜0.05.The systolic velocity of tricuspid annulus were increased with a gestational age of 24-31.6 weeks,P＜0.05.The Em/Am ratio of mitral annulus was decreased with a gestational age of 24-40 weeks.The Em/Am ratio of tricuspid annulus was decreased with a gestational age of 28-40 weeks,P＜0.01.The MCA-PSV was increased with a gestational age of 24-35.6 weeks,P＜0.05.3.Compared to well maternal glucose control,the fetal diastolic thickness of left ventricular wall and thickness of IVS were increased significantly in poorly maternal glucose control,P＜0.05. There was no difference on fetal cardiac function between maternal glucose control.4.The fetal diastolic thickness of IVS,Em of tricuspid annulus,systolic velocity of mitral annulus and UA-PI were corrected with perinatal morbidity.Conclusions:Among maternal glycometabolic disturbance,the thickness of fetal ventricular wall and IVS in GDM were thickest.Compared to normal pregnancy,the thickness of ventricular and IVS were thicker in fetuses of GDM.The systolic function was increased significantly,but diastolic function was decreased more seriously.The fetal diastolic thickness of left ventricular wall and thickness of IVS were increased significantly in poorly maternal glucose control.The fetal diastolic thickness of IVS,Em of tricuspid annulus,systolic velocity of mitral annulus and UA-PI were corrected with perinatal morbidity.Section 3.The assessment fetal cardiac function in preeclampsia pregnanciesObjective:To explore the effects of fetal cardiac function in preeclampsia,and to investigate whether there was difference in fetal cardiac function between AGA and FGR in preeclampsia pregnancy.Methods:A cross-sectional prospective study of 44 preeclampsia pregnancies with a gestational age of 24-40 weeks,including 26 AGA fetuses and 18 FGR fetuses.The parameters were the same as section 1.The fetuses in section 1 between 24 to 40 weeks acted as normal control group.Results:1.Compared with normal pregnancy,systolic fraction of right ventricular in AGA fetuses was decreased significantly,P＜0.01.The systolic velocity of ventricular wall and atrioventricular annulus were similar between fetuses of normal pregnancy and AGA fetuses ofpreeclampsia,P>0.05.Compared to normal pregnancies,systolic velocity of atrioventricular annulus were decreased significantly in FGR fetuses of pregnancy, P＜0.05.2.Compared to fetuses in normal pregnancy,Em and Em/Am ratio of mitral annulus in AGA fetuses of preeclampsia were decreased significantly,P＜0.05.Em,Am of left ventricular wall and mitral annulus were decreased significantly in FGR fetuses of pregnancy,P＜0.01.Em/Am ratio of left ventricular wall and mitral annulus were similar between normal pregnancy and FGA fetuses of preeclampsia.Compared to AGA fetuses in preeclampsia,Am of mitral annulus in FGR fetuses were decreased significantly, P＜0.05.3.The Em/Am ratio of tricuspid annulus in AGA fetuses of preeclampsia was lower than normal pregnancy,P＜0.05.E/A ratio of tricuspid valves,Em,Am and Em/Am ratio of right ventricular wall were similar between normal pregnancy and AGA fetuses in preeclampsia,P＞0.05.Em and Em/Am of right ventricular wall in FGR fetuses of preeclampsia were lower than normal pregnancy,P＜0.01.Em of tricuspid annulus were lower than normal pregnancy,P<0.05.No difference were observed about right ventricular diastolic function between AGA and FGR fetuses in preeclampsia,P>0.05.4. Compared to normal pregnancy,DV-S/A ratio and MCA-PSV in fetuses of preeclampsia were increased significantly,P<0.05.MCA-RI was lower,P<0.05.UA-PI,UA-RI and UA-S/D ratio were increased significantly,P<0.01.Compared with AGA fetuses of preeclampsia,MCA-PI,MCA-RI in FGR fetuses were decreased significantly,P<0.05. UA-PI,UA-RI and UA S/D ratio in FGR fetuses of preeclampsia were higher than AGA fetuses although the difference had no significance,P>0.05.Conclusion:Compared with normal pregnancy,heart diastolic function in AGA fetuses of preeclampsia were impaired significantly,Fetal heart systolic and diatolic function in FGR fetuses of preeclampsia was impaired even more seriously.The effect of brain-sparing was more dominant in FGR fetuses of preeclampsia pregnancy.Section 4.Cardiac dysfunction in FGR fetusesObjective:To investigate cardiac function changes in FGR fetuses and explore valuable parameters in predicting perinatal morbidity.Methods:A cross-sectional prospective study of 43 FGR fetuses with a gestational age of 28-40 weeks.The parameters were the same as section 1.The fetuses in section 1 between 28 to 40 weeks acted as normal control group.To analyze the relation between parameters and fetal outcome.Results:1.The shortening fraction(SF) in FGR fetuses was lower than normal pregnancy,P<0.01.The systolic velocity of ventricular wall and atrioventricular annulus in FGR fetuses was lower than normal pregnancy,P<0.01.2.The Em and Am of left ventricular wall in FGR fetuses was lower than normal pregnancy,P<0.01.The Em of interventricular septum(IVS) in FGR fetuses was lower than normal pregnancy,P<0.01.The Am of IVS in FGR fetuses was lower than normal pregnancy,there was no significant difference,P>0.05.The Em of right ventricular wall in FGR fetuses was lower than normal pregnancy,P<0.01.The Am of right ventricular wall in FGR fetuses was lower than normal pregnancy,P<0.05.The Em of mitral annulus in FGR fetuses was lower than normal pregnancy,P<0.01.The Am of mitral annulus in FGR fetuses was lower than normal pregnancy,P<0.05.The Em of tricuspid annulus in FGR fetuses was lower than normal pregnancy,P＜0.01.The Am of tricuspid annulus in FGR fetuses was lower than normal pregnancy,there was no significant difference,P＞0.05.The Em/Am ratio of left ventricular wall in FGR fetuses was lower than normal pregnancy,P＜0.05.The Em/Am ratio of IVS,right ventricular wall and mitral annulus in FGR fetuses was lower than normal pregnancy,there was no significant difference,P＞0.05.The Em/Am ratio of tricuspid annulus in FGR fetuses was lower than normal pregnancy,P＜0.01.3.Compared with normal pregnancy,the DV-S/A,UA-PI,UA-RI in FGR fetuses were increased significantly,P＜0.01.The MCA-PI,MCA-RI were decreased significantly,P＜0.01.Gestational age and birth weight were correlated with neonatal outcome,P＜0.01.Next to gestational age and birth weigh,Em of tricuspid annulus,UA-Pland MCA-RI were correlated to neonatal outcome.Conclusion:Compared with normal pregnancy,cardiac function in FGR fetuses were impaired significantly.Gestational age and birth weight were correlated with neonatal outcome significantly,UA-PI,Em of tricuspid annulus and MCA-RI were correlated to neonatal outcome.