LITHUANIAN UNIVERSITY OF HEALTH SCIENCES LUHS LIBRARY REPOSITORY

Vaisiaus kraujotakos tyrimų vertė blužnies ir vidurinėje smegenų arterijose rezus izoimunizacijos atvejais

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dc.contributor.author Mačiulevičienė, Regina
dc.date.accessioned 2017-08-21T08:06:55Z
dc.date.available 2017-08-21T08:06:55Z
dc.date.issued 2006
dc.identifier.uri http://repository.lsmuni.lt/handle/1/60001
dc.description.abstract ABBREVIATIONS A – amniocentesis DA – deceleration angle FMH – fetomaternal haemorrhage MCA – middle cerebral artery MoM – multiples of median PI – pulsatility index PSV – peak systolic velocity RI – resistance index SA – splenic artery SGA – small for gestational age HDN – haemolytic disease of newborn 1. INTRODUCTION Rhesus alloimmunization occurs when a rhesus negative woman has an immunologic response to a paternally derived red-cell antigen that is foreign to the mother and inherited by the fetus. Rhesus alloimmunization and haemolytic disease of the newborn continues to occur as a serious complication of pregnancy despite well-organized antenatal antiD prophylaxis programs. At the Perinatal Center of Kaunas University of Medicine the incidence has remained stable at around 60 cases of alloimmunized pregnancies and from 30 to 40 cases of haemolytic disease of newborn annually. Perinatal mortality in cases of rhesus alloimmunization has been estimated to be at around 1 to 3.5 percent. Due to failure to apply or comply with antiD prophylaxis guidelines and limitations of the prophylaxis rhesus sensitization continues to occur. Rhesus alloimmunization is diagnosed when the test of a rhesus negative woman for red cell alloantibodies is positive. Prognosis for the fetus and perinatal outcomes depends much on how severely the fetus is affected by the disease at the time of diagnosis. The main pathological entity of the disease is fetal red blood cell destruction and hemolytic anaemia. Most textbooks and clinical guidelines still consider amniocentesis and amniotic fluid spectrophotometry to estimate bilirubin levels (expressed as _OD450), plotted in Liley’s chart, the cornerstone of the management of rhesus disease. The management of pregnancy is still based on amniotic fluid spectrophotometry. Accepted recommendations are to perform serial amniocentesis and according to _OD450 readings to decide on the timing of cordocentesis, the need for intrauterine blood transfusion, to decide on the delivery date and to induce labour or to perform Cesarean section. Amniocentesis and amniotic fluid spectrophotometry for the management of rhesus disease were introduced at the Clinic of Obstetrics and Gynecology of Kaunas University of Medicine in 1967 by Professor D.K. Baliutavièiene (Baliutavièiene D.K., 1967). The main disadvantages of this method are related to its invasive nature. Complication rates of amniocentesis are around 1 percent above the background risk (Oepkes D., 2003) and include infection, bleeding, fetal bradycardia, premature rupture of the membranes and fetal death. According to some investigators the incidence of fetal loss during amniocentesis is 0.25-1 percent (Urbaniak S.J. et al., 2000). Fetal mortality associated with cordocentesis is estimated to be from 1 to 3 percent, but may increase up to 15 percent in cases of hydropic fetuses (Urbaniak S.J. et al., 2000). Both of these invasive procedures potentially increase sensitization. Nicolaides et al. found the clinical usefulness of amniotic fluid analysis before 27 weeks of gestation to be disappointing (Nicolaides K.H. et al., 1986). The primary goal of noninvasive diagnostic methods is the selection of patients eligible for invasive testing and treatment. However, for decades there was not any reliable noninvasive method to evaluate the severity of fetal disease in rhesus alloimmunization. Noninvasive tests, using ultrasound and Doppler techniques to predict fetal anemia and to estimate the time for amniocentesis or cordocentesis have been studied extensively in the last two decades. Several Doppler indices (for example, Doppler flow velocity measurement in the descending aorta and ductus venosus) showed disappointing results as predictors of fetal anemia. Most relevant for clinical practice are the good results described for Doppler measurements in the intrahepatic umbilical vein and the middle cerebral artery (Oepkes D., 2000). These flow velocities showed good reproducibility. The promising results from retrospective studies of peak systolic velocity in the middle cerebral artery (MCA PSV) (Vyas S. et al., 1990; Oepkes D. et al., 1994; Mari G. et al., 1995), were confirmed by semi-prospective (Mari G. et al., 2000) and prospective studies (Iskarios J., 1998; Deti L., 2003; Nishie E.N. et al., 2003; Pereira L. et al., 2003). The use of MCA-PSV could have detected all the cases of significant fetal anemia requiring transfusion and would have avoided approximately 70 percent of the unnecessary invasive procedures (Mari G., 2000). However, only one study was classified as level 1 evidence in a systematic review on noninvasive techniques to detect fetal anemia due to red cell alloimmunization (Divakaran T.G., 2001). A recent review has reported that the assessment of fetal anemia with MCA-PSV needs further evaluation before being incorporated into the management protocol for this condition (Harrington K. et al., 2002). The fetal spleen plays a central role in red cell alloimmunization. It is both responsible for the final destruction of the corpuscles damaged by circulating antibodies and also helps to compensate for the resulting anemia by manufacturing new red blood cells. Doppler data provide convincing evidence of hyperdynamic circulatory changes in the splenic artery resulting from the anemia (Nicolaides K.H. et al., 1990). It was hypothetized that both the site of red blood cell destruction and production and changes in splenic artery circulation, as assessed by Doppler velocimetry, would correlate with the degree of fetal alloimmunization and the severity of anemia (Rosenberg A.A. et al., 1985). Bahado-Singh et al. studied splenic artery Doppler waveforms. They found that the deceleration angle between the line describing the average slope during the diastolic phase of the cycle and the vertical axis predicted fetal anemia with a sensitivity of 100 percent and an 8.8 percent false positive rate (Bahado-Singh R. et al., 1999). According to Bahado-Singh et al. it was also shown that Doppler peak systolic velocity in the splenic artery predicts severe anemia of the fetus (Bahado-Singh R. et al., 2000). Although these few studies showed the possible potential of the splenic artery Doppler in the management of rhesus alloimmunisation, more investigations were needed. We conducted a prospective study designed to determine the value of Doppler indices of splenic artery and middle cerebral artery velocimetry in prediction of fetal anemia and to compare the values of these indices with the value of the amniotic fluid spectrophotometry. 2. AIM AND OBJECTIVES OF THE STUDY Aim of the study The aim of this study was to assess changes of blood flow in the splenic artery and middle cerebral artery in cases of rhesus alloimmunization and to establish whether indices of Doppler velocimetry in splenic artery and middle cerebral artery are valuable for the prediction of fetal anemia in cases of rhesus alloimmunization. Objectives of the study The objectives of this study were as follows: 1. To establish nomograms of Doppler indices for various gestational ages in splenic artery and middle cerebral artery. 2. To determine the value of the peak velocity of systolic blood flow in the middle cerebral artery for the prediction of fetal anemia due to maternal red cell alloimmunization. 3. To determine the value of the Doppler velocimetric indices of the splenic artery for the prediction of fetal anemia due to maternal red cell alloimmunization. 4. To compare the value of the Doppler velocimetric indices of the middle cerebral artery and the splenic artery for the prediction of fetal anemia due to maternal red cell alloimmunization. 5. To compare the value of the Doppler velocimetric indices of the middle cerebral artery and the splenic artery with the value of the antibody titre and amniotic fluid spectrophotometry for the prediction of fetal anemia due to maternal red cell alloimmunization. 6. To determine the value of the Doppler velocimetric indices of the splenic artery and middle cerebral artery for the prediction of pregnancy and perinatal outcomes. 7. To establish correct criteria for determing the degree of fetal anemia and to propose guidelines for the management of rhesus alloimmunized pregnancies. 3. PATIENTS AND METHODS 3.1. General design of the study This prospective case-control study with the intention to treat was undertaken at the Clinic of Obstetrics and Gynecology of Kaunas University of Medicine from January 2001 to October 2004. Women were referred to the study center for amniocentesis and amniotic fluid spectrophotometry. According to DOD450 readings plotted in Liley’s chart the pregnancy management plan was scheduled. Doppler examination of the middle cerebral artery and splenic artery was performed before the first and each subsequent amniocentesis procedure in all cases. The principal doctor of each patient was informed about the results of Doppler examination and this could influence the management plan in every case. Out of this population we included in our study group those 157 pregnant women diagnosed with the rhesus alloimmunization who delivered at Kaunas Perinatal Center. Retrospectively according to the hemoglobin level of the newborn the study group was divided into the case group and the control group. The case group comprised 66 (41.7%) women who delivered anemic babies. According to the severity of the anemia (to evaluate the degree of anemia we used the concept described by K. H. Nicolaides) the group was further divided into the three subgroups of mild (case subgroup 1, n=25 (16%)), moderate (case subgroup 2, n=23 (14.1%)) and severe (case subgroup 3, n=18 (11.6%)) anemia. The control group comprised 91 (58.3%) women who delivered babies with no anemia or haemolytic disease of the newborn. 3.2. Inclusion and exclusion criteria for the cases The following inclusion criteria for the study group patients were set: 1.
dc.language.iso lit
dc.subject Vidurinė smegenų arterija
dc.subject Blužniies arterija
dc.subject Doppler velocimetrytrija
dc.subject Splenic artery
dc.subject Middle cerebral artery
dc.subject Doplerome fetal anemia
dc.subject Vaisiaus anemija
dc.title Vaisiaus kraujotakos tyrimų vertė blužnies ir vidurinėje smegenų arterijose rezus izoimunizacijos atvejais
dc.title.alternative Fetal splenic artery and middle cerebral artery doppler velocimetry in cases of Rhesus alloimmunization
dc.type Daktaro disertacija


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