| l.BackgroundsCongenital heart disease is one of the most common deformities in the fetal period. Domestic literature reports on the overall incidence of8.2%o, in live births in up to6.7%o, in dead baby deformity in up to168.8%o. which is only lower than that of neural tube defects. Congenital heart disease is the most common heart disease in children period. Complex heart disease is very harmful to the fetus, and brought heavy spirit and economic burden to the society and family. Some congenital heart disease can be corrected in utero, and some can be immediately treated postnatally. Some is deadly deformity, need to immediate treat after diagnosis. Because congenital heart disease form s complexly and has various kinds, it is very important to make accurate diagnosis as early as possible for clinical guidance, whether to continue the pregnancy or not and how to deal with the neonate postnatally. Meanwhile., it is the new requirement for prenatal diagnosis to medical workers. The heart of embryonic development, from the most early primitive form of heart to four chamber and two large blood vessels in the heart,have finished this process at11weeks.At this time,the fetus has grown at a certain size, the heart has differentiated form. and nuchal translucency scanning is performed in this stage.If fetal structures was observed at the same time,it will not increase the number of inspection. In the literatures, fetus with normal chromosome, heart structure abnormalities correlated with increased NT. Early trimester scanning for aneuploidy has been widely used. With the development of equipment and ultrasound diagnosis technology,it has been become true to scan structural abnormalities in the first trimester.and become more and more atractive.Because of high incidence of congenital heart disease, cardiac anomalies screening is very difficult and important.The reported heart disease diagnosed in the first trimester included hypoplastic left heart syndrome,hypoplastic right heart syndrome,atrial and ventricular septal (500-900ms), ERP (Verbruggen,2007) heterogeneous, heart ectopic,big ventricular septal defect. Ebstein anomaly,and absent pulmonary valve.Prenatal accurate diagnosis of cardiac anomaly significance lies in clinical guidance postpartum processing. Such as the left heart dysplasia syndrome is highly fatal heart abnormalities. and25%of babies die in one week after birth. It is of great significance to diagnosis prenatally in time for perinatal P3b (200-500ms), heart transplantation and Norwood suture.In this text,we make a research on a part of the research of prenatal imaging screening and new diagnostic technologies for major fetal structural anomalies. and supported by National Key Technologies R&D Program.2.Objective and and significanceImproving population quality is one of our basic state policy.Each expectant mother dreams of giving birth to a healthy, lovely child.It is very important to prevent birth defects.Research shows that more than80%of the fetal structure malformation formed before12weeks.Therefore,many defects can be diagnosed in this stage,sush as body stalk anomaly,anencephaly,alobar holoprosencephaly, omphalocele,gastroschisis,megabladder,and so on. As one-step clinical assessment of risk was carried out, and high resolution the application of ultrasonic developed, more and more fetus with serious structural malformations were diagnosed in the early pregnancy. In the foreign literatures, the sensitivity of diagnosis of fetal abnormalities ranged from51%to61%in the first trimester. If the diagnosis of structure abnonnalities can be advanced from the second trimester to the early pregnancy, and it will be helpful for patients to decide whether continued the pregnancy or not.Abortion was performed in order to lessen pain in pregnant women when serious anomaly was diagnosed. Prospective study was perforned to discuss heart disease diagnosis and find the ultrasonographic features in the11～13+6weeks.The feasibility of diagnosis was assessed.including the accuracy, specificity and sensitivity, then developed a simple and feasible ultrasonic method to diagnose fetal heart abnormalities in11～13+6weeks.Then more theoretical and technical supports could be provided for prenatal diagnosis.3.Research methodsAll pregnant women coming to our hospital were given nuchal translucency in11to13+6weeks.All scannings were performed in strict accordance with standard of inspection of the British fetal medical foundation. Measurement parameters include CRL,NT,nasal bones, ductus venosus.Fetal brain and facial structure were assessed (negative slow wave, NSW)(Sohn,2000; Collette,2002) assessed by limbs long axis coronary view. and fetal heart was observed by four chamber view and three vessel trachea view maping colour doppler in order to ObjectiveThe function of central executive system function include election, planning, switching, extraction, checking and so on. The neural mechanism of task switching remain to be clarified. It is an often replicated finding that switching between tasks is associated with longer latencies and higher error rates, which is known as the task-switch cost (Monsell,2003; Rogers,1995). A majority of theories explaining the task-switch cost are at least partly based on the observation that increasing the preparation time with advance knowledge of the upcoming task results in faster response latencies in general and in the reduction of the difference between task repetitions and task alternations. But at least as important for the theorizing about task switching is the finding that although advance task preparation reduces the switch cost, it never really eliminates the switch cost (Rogers,1995; Goffaux,2006; Monsell,2006; Sohn,2000), suggesting that advance task preparation, and endogenous control obtained and the CRL should be measured with the fetus in the neutral position, in general, is restricted in nature. This remaining residual switch cost received much attention in the task-switching literature and will be the focus of the present study. However, some researches suggested that residual switch cost could be eliminatedjust by short-time presentation for the task cue (Mayr,2001; Verbruggen,2007). But No study has been carried out on the neural mechanism of this phenomenon. Our research used a Chinese Stroop switching task paradigm. We aimed to such as:tricuspid reversed flow and a single flow. In a standard4CHV, investigate the neural mechanism of task switching cost in the task preparation phase can be showed mapping CDFI,which formed by the confluence of the ductus arteriosus to the aortic isthmus.and task execution stage by changing the cue presentation time. In the ductus venosus studies the following criteria were fulfilled:(a) the examinations were undertaken during fetal quiescence,(b) the magnification of the image was such that the fetal thorax and abdomen occupied the whole screen,(c) a right ventral mid-sagittal view of the fetal trunk was obtained and color flow mapping was used to demonstrate the umbilical vein, ductus venosus and fetal heart,(d) the pulsed Doppler sample was small (0.5-1.0mm) to avoid contamination from the adjacent veins and it was placed in the yellowish aliasing area which is the portionimmediately above the umbilical sinus,(e)the insonation angle was less than30°,(f) the filter was set at a low frequency (50-70Hz) to allow visualization of the whole waveform, and (g) the sweep speed was high (2-3cm/s) so that the wavefonns were widely spread allowing better assessment of the a-wave. Waveforms were assessed qualitatively and considered to be abnormal if the a-wave was reversed.Statistical methods: Use statistical software packages of SPSS13.0. p<0.05wasconsidered significant throughout. Age, CRL and NT value were calculated as X±S, and95percentile and99percentile of NT value were calculated. Scatter plot between CRL and NT value was drawn, and so did box plot among the3groups Crosstabs analysis was performed to compare the visualization rates of4CH and3VT among the3groups.Amniocentesis and reexamination were suggested for fetus with major heart disease. Autopsy was performed for termination of pregnancy. Echocardiography was performed for the neonate.4.ResultsAccording to the scatter-plot chart,11～13+6weeks NT increased gradually with gestational age increased. The95th percentile was2.6mm. and the99th percentile was3.7mm.The display rate of4-chamber heart view and three-vessel-trachea view increased with the increase of gestational age in11～13+6weeks. The rate of4-chamber heart view was90.5%,95.7%,95.9%in11to1+6weeks (CRL45～57mm),12～12+6weeks (CRL58-70mm),13～13+6weeks (CRL71～84mm) respectively. The rate of three-vessel-trachea view was86.9%、93.8%、94.2%in11～11+6weeks (CRL45～57mm).12～12T6weeks (CRL58～70mm),13～13+6weeks (CRL71～84mm), respectively.The total rate of4-chamber heart view and three-vessel-trachea view were95.1%and92.5%in11～13+6weeks. The4-chamber view displayed more easily than three-vessel-trachea view.A total of679cases included in our study. Twenty-eight cases with major heart disease were diagnosed. and4cases misdiagnosed. The detection rate was87.25%, and the misdiagnosis rate was12.75%. Of these28cases,27cases terminated the pregnancy. The rest one was one twin, who diagnosed as double outlet right ventricle, delivered in term. Two of the4misdiagnosed cases terminated the pregnancy,and2delivered in term. All of28cases with cardiac anomalies have different abnormal ultrasound performance in the4-chamber view and/or three-vessel-trachea view. The sensitivity of increased NT for cardiac disease was81.25%(26/32), specificity was94.9%(614/647), the positive predict value was44.07%(26/59), and negative predict value was99%(614/620) in11～13+6weeks. The sensitivity of a wave reverse or absence for fetal heart abnormalities was25%(8/32), specificity was99.38%(643/647), the positive predict value was66.67%(8/12), and negative predict value was96.4%(643/667). All of the4misdiagnosed cases were diagnosed as major cardiac disease in the second trimester scanning,including2cases of tetralogy of Fallot.1case of hypoplastic distal aortic arch, ventricular septal defect, aorta dysplasia.1case of mirror right aorta, left arterial duct. The cause of misdiagnosis was failure of obtaining4CH or3VT view.5.Conclusions It is feasible and effective for experienced sonographe to observe fetal heart structure in11～13+6weeks using the4-chamber view and three-vessel-trachea view screened associated with aneuploidy chromosome abnormality soft markers. serious fetal heart abnormalities, did not increase the number of examination, and measuring NT and obtaining ductus venosus can improve detection rate the cardiac anomaly in the first trimester. Color doppler techniqu imaging is indispensable conditions. Severe fetal heart abnormalities can be diagnosed by experienced fetal echocardiogram experts, and the time performed could be advanced from second trimester to the early pregnancy. At meantime, associated NT value, venous ductus can be further screen fetal chromosomal abnormalities. The study is feasible and effective, and can be applied widely. |
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