Amniotic Fluid Spectrophotometry Research Articles

Rh alloimmunization: Doppler or amniotic fluid analysis in the prediction of fetal anemia?

Compare the results of amniocentesis and those of middle cerebral artery peak systolic velocity to detect anemic fetuses in Rh alloimmunized pregnancies. Descriptive observational study involving 99 consecutive Rh-negative pregnancies: 74 alloimmunized patients submitted to amniotic fluid spectrophotometry (group 1) and 25 alloimmunized cases managed with Doppler ultrasonography (group 2). Variables analyzed were the following: need for neonatal transfusion and neonatal hematocrit. Neonatal hematocrit was significantly lower and the need for neonatal transfusion was significantly higher in cases managed with spectrophotometry compared to those managed with Doppler. Infants managed with Doppler velocimetry had higher hematocrit and less need for neonatal transfusion, suggesting that this non-invasive method of monitoring fetal anemia may best preserve the neonate.

P09.06: Pregnancy outcome in Rh alloimmunized patients managed through amniotic fluid spectrophotometry or Doppler ultrasonography of the fetal middle cerebral artery

P09.06: Pregnancy outcome in Rh alloimmunized patients managed through amniotic fluid spectrophotometry or Doppler ultrasonography of the fetal middle cerebral artery

Pregnancy outcome for Rh-alloimmunized women

Objective: To compare perinatal results of Rh-alloimmunized pregnancies managed with spectrophotometric amniotic fluid analysis or fetal middle cerebral artery Doppler ultrasonographic velocimetry. Method: A descriptive observational study involving 291 consecutive Rh-negative pregnancies. Group 1 consisted of 74 isoimmunized women managed with amniotic fluid spectrophotometry; group 2 of 25 isoimmunized women managed with Doppler ultrasonography; and group 3 of 192 nonimmunized Rh-negative women. The variables analyzed were need for intrauterine or neonatal transfusion, mode and time of delivery, birth weight, neonatal hematocrit, and perinatal mortality. Results: Need for intrauterine transfusion, birth weight, prematurity, rate of cesarean section, and perinatal mortality were similar in groups 1 and 2. Neonatal hematocrit was significantly lower and the need for neonatal transfusion was significantly higher when spectrophotometry rather than Doppler ultrasonographic velocimetry was used. Conclusion: Fetuses managed with Doppler ultrasonographic velocimetry had a higher hematocrit at birth and a lesser need for neonatal transfusion, suggesting that this noninvasive method of monitoring fetal anemia is a better choice.

Management of Pregnancies Complicated by Anti-E Alloimmunization

There is limited information published about anti-E alloimmunization. We review our experience at The Ohio State University to determine appropriate management strategies. We reviewed records from June 1959 to April 2004 to identify pregnancies managed for anti-E alloimmunization. Information collected included antibody titers, DeltaOD450 values, Liley zones, middle cerebral artery peak systolic velocity, fetal and neonatal hemoglobin (Hb) and antigen typing, fetal and neonatal direct antiglobulin test, and outcomes. Pregnancies affected only by anti-E alloimmunization with a positive direct antiglobulin test or positive E antigen typing in the fetus or newborn were included. A total of 283 pregnancies were identified with anti-E. Of these, 32 pregnancies in 27 women were at risk for hemolytic disease of the fetus or newborn from anti-E only and had complete records. Sixteen of these pregnancies had titers greater than or equal to 1:32, with amniocenteses performed for DeltaOD450 in 15 pregnancies. Values of DeltaOD450 in zone IIB or zone III in combination with serologic titers identified all pregnancies with fetal or neonatal anemia. Five of 32 (15%) fetuses had Hb less than 10 g/dL and 1 fetus had hydrops fetalis due to anti-E alloimmunization. There was 1 perinatal death attributable to anti-E hemolytic disease of the fetus or newborn. Middle cerebral artery peak systolic velocity was measured in 2 cases and corroborated information obtained from amniocentesis. Anti-E alloimmunization can cause hemolytic disease of the fetus or newborn requiring prenatal intervention. Based on our population, clinical strategies developed for Rh D alloimmunization using maternal serology, amniotic fluid spectrophotometry, and fetal blood sampling are useful in monitoring E alloimmunization.

Historical Perspectives: The Underpinnings of Neonatal/Perinatal Medicine

The accompanying article by Dr. John Bowman was contributed in response to a request to place his important paper (1) into context. Dr. Bowman is the former Medical Director of the Winnipeg Rh Laboratory and a Distinguished Professor Emeritus at the University of Manitoba. Although not the first to describe the use of Rh immune globulin, the clinicians in Winnipeg were leaders in the use of antenatal prophylaxis. At present, Rh isoimmunization is extremely rare, in large measure because of the pioneers described by Dr. Bowman. Antenatal administration of anti-D immune globulin now is “standard operating procedure,” but this was not always the case. It is important to understand how the problem of Rh isoimmunization has been virtually eliminated from neonatal practice. 1. ↵ Bowman JM, Chown B, Lewis M, Pollock JM. Rh isoimmunization during pregnancy: antenatal prophylaxis. Can Med Assoc J. 1978;118:623–627 [OpenUrl][1][Abstract][2] # Historical Perspectives: The Underpinnings of Neonatal/Perinatal Medicine {#article-title-2} Rh hemolytic disease was reported initially by a French midwife in 1609. She described the birth of twins: the first, who was pale and bloated with fluid (hydrops fetalis), died within minutes of birth; the second, in much better condition, became deeply jaundiced in the first 3 days after birth, developed rigidity, lay in a position of opisthotonus (kernicterus), and died on the fourth day after birth. Hydrops fetalis and kernicterus were not linked again until 323 years later. In 1932, Diamond and associates determined that they were simply different aspects of a spectrum representing the same disorder. The more severe, hydrops, was characterized by hemolysis of fetal red blood cells that produced severe anemia, followed by hepatosplenomegaly, extramedullary erythropoiesis, and the outpouring of immature nucleated fetal red cells, from which Diamond coined the diagnostic term “erythroblastosis fetalis.” Uncovering the cause of the fetal red blood cell hemolysis had to await the discovery of the Rh blood group system by Landsteiner and Wiener in 1940 and the subsequent determination in 1941 by Levine that the cause of hemolytic … [1]: {openurl}?query=rft.jtitle%253DCanadian%2BMedical%2BAssociation%2BJournal%26rft.stitle%253DCMAJ%26rft.issn%253D0008-4409%26rft.aulast%253DBowman%26rft.auinit1%253DJ.%2BM.%26rft.volume%253D118%26rft.issue%253D6%26rft.spage%253D623%26rft.epage%253D627%26rft.atitle%253DRh%2Bisoimmunization%2Bduring%2Bpregnancy%253A%2Bantenatal%2Bprophylaxis%26rft_id%253Dinfo%253Apmid%252F77714%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [2]: /lookup/ijlink?linkType=ABST&journalCode=cmaj&resid=118/6/623&atom=%2Fneoreviews%2F3%2F11%2Fe223.atom

Diagnostic and therapeutic proceedings in pregnancies with blood group incompatibility: A retrospective analysis over 30 years

To examine the development during the past 30 years of diagnostic and therapeutic procedures in pregnancies with blood group incompatibility. We evaluated 193 pregnancies with maternal red blood alloimmunisation treated at our hospital. At least one amniotic fluid spectrophotometry was performed. We observed a reduced average age of the patients, a reduced parity and an increase in the number of amniotic fluid examinations per pregnancy in the course of time. Amniotic fluid examinations tended to be performed earlier in pregnancy. Gestational time was reduced, the rate of spontaneous vaginal deliveries remained unchanged. The proportion of anti-D-alloimmunisation decreased in relation to other antigens and the severity of the cases increased (assessed according to the findings of the spectrophotometric amniotic fluid examinations performed while using the semiquantitative method of Liley). The haemoglobin values of the newborn, without intrauterine transfusions, were unchanged and the number of intrauterine deaths decreased. The rate of postnatal transfusions decreased dramatically, whereas the rate of phototherapeutic approaches increased. The spectrum of the antigens causing fetal haemolytic disease has changed during the last 30 years and so have the diagnostic and therapeutic procedures.

The management of hemolytic disease in the fetus and newborn

Rh hemolytic disease (HDN) is the prototype of maternal alloimmunization and fetal hemolytic disease. There are other antigens capable of causing alloimmunization and hemolytic disease such as c, Kell, and Fya. Rh immunization is usually caused by a prior Rh positive fetal maternal transplacental hemorrhage, which occurs in at least 75% of pregnancies. Unless treated, hemolytic disease will result in kernicterus or fetal hydrops in 25% of cases, respectively. Neonatal exchange transfusion has eradicated kernicterus. Measures available to predict severity of fetal hemolytic disease are maternal antibody titers, prior history of hemolytic disease, in vitro cell-mediated maternal antibody functional assays, amniotic fluid spectrophotometry, ultrasound fetal assessment, and fetal blood sampling. The Rh or Kell antigen status of the fetus may be determined by amniotic fluid PCR testing. The management of the severely affected fetus consists of early delivery, with or without fetal transfusions, depending on the gestation of the fetus. With the use of these diagnostic and treatment measures, perinatal mortality from hemolytic disease of the fetus and newborn has been reduced in Manitoba, population one million, from 100 per year in the early 1940s to 1 every 3 years in the mid 1990s.

Second-trimester echogenic bowel and intraamniotic bleeding: Association between fetal bowel echogenicity and amniotic fluid spectrophotometry at 410 nm

OBJECTIVE: Our purpose was to determine whether the presence of heme pigments in amniotic fluid is associated with the ultrasonographic findings of increased fetal bowel echogenicity in the second trimester. STUDY DESIGN: Spectrophotometric analysis of amniotic fluid for optical density at 410 nm was prospectively performed to study the presence of heme pigments in (1) 104 pregnancies undergoing second-trimester amniocentesis for routine cytogenetic indications and (2) in 14 pregnancies undergoing amniocentesis for prenatal karyotyping because of fetal strongly echogenic bowel. In the routine amniocentesis group the fetal small bowel echogenicity was assessed immediately before amniocentesis and classified as nonechogenic ( n = 64), mildly echogenic ( n = 36), or hyperechogenic ( n = 4) with the fetal iliac wing and liver used as references. Only amniotic fluid specimens that were obtained at the first attempt and that were not blood-stained were included in this study, with the first milliliter being discarded in all samples. RESULTS: In the routine amniocentesis group abnormal amniotic fluid optical density readings were significantly more frequent in fetuses with increased bowel echogenicity compared with those with nonechogenic bowel (8/40 [20%] vs 3/64 [5%], respectively; p < 0.001). In the hyperechogenic bowel group abnormal amniotic fluid optical density readings were found in four samples (29%). Overall, 12 of 54 fetuses (22%) with increased bowel echogenicity had a detectable peak at 410 nm. Three of the 12 (25%) fetuses with echogenic bowel and positive readings for hemoglobin were chromosomally abnormal. CONCLUSIONS: Fetal small bowel echogenicity is associated with the presence of heme pigments in amniotic fluid as determined by amniotic fluid optical density at 410 nm. Swallowing of amniotic fluid after intraamniotic bleeding seems implicated in the etiology of second-trimester echogenic bowel in both euploid and aneuploid fetuses. (A M J O BSTET G YNECOL 1996;174:839-42.)

Spectrophotometry of amniotic fluid: a simple and rapid method for distinguishing between gestational sacs in second-trimester amniocentesis of twin pregnancies

To evaluate the use of an alternative and simple spectrophotometric method that could replace the intraamniotic injection of dye in the second-trimester amniocentesis of twins. Optical densities (OD) of amniotic fluid (AF) obtained at second-trimester genetic amniocentesis were measured at 360 nm. Comparison was made between 36 twin pregnancies and 60 singleton controls. The mean difference in OD between two samples taken from the same sac of singleton pregnancies was very small (mean 0.004, standard deviation [SD] 0.003). However, samples drawn from each of the twin pairs' amniotic sacs varied widely (raw mean 0.176, SD 0.223; median 0.096, range 0.011–0.943). The difference between the groups was highly significant statistically ( P < .001). Our preliminary experience with spectrophotometry of AF in twin amniocentesis suggests that this simple test may be useful in ascertaining that the AF samples were obtained from each of the two gestational sacs.

Second trimesterechogenic bowel and intra-amniotic bleeding: Correlation between fetal small bowel echogenicity and amniotic fluid spectrophotometry at 410nm: [formula omitted], R. Reid, x O. Prendiville, x R. Chapman, x N.M. Fisk. x Centre for Fetal Care, Royal Postgraduate Medical School, Institute of Obstetrics and Gynaecology, Queen Charlotte's and Chelsea Hospital, and Department of Chemical Pathology, Hammersmith Hospital, London, U.K.

Second trimesterechogenic bowel and intra-amniotic bleeding: Correlation between fetal small bowel echogenicity and amniotic fluid spectrophotometry at 410nm: [formula omitted], R. Reid, x O. Prendiville, x R. Chapman, x N.M. Fisk. x Centre for Fetal Care, Royal Postgraduate Medical School, Institute of Obstetrics and Gynaecology, Queen Charlotte's and Chelsea Hospital, and Department of Chemical Pathology, Hammersmith Hospital, London, U.K.

256 Amniotic fluid spectrophotometry is useful after 20 weeks gestation in the care of pregnancies complicated by red blood cell isoimmunization

256 Amniotic fluid spectrophotometry is useful after 20 weeks gestation in the care of pregnancies complicated by red blood cell isoimmunization

Abnormal amniotic fluid spectrophotometry in a pregnancy associated with fetal duodenal atresia

Abnormal amniotic fluid spectrophotometry in a pregnancy associated with fetal duodenal atresia

Heparin-induced inhibition of 1,25-dihydroxyvitamin D formation

vise intrauterine transfusion because of the suspicion that normal clearance of the amniotic fluid bilirubin may be impeded by the presence of duodenal atresia, which keeps amniotic fluid bilirubin high. This theory has been previously published without case studies.’ Sources of error in amniotic fluid spectrophotometry included blood, maternal or fetal, meconium, urine, ascitic fluid, and congenital anomalies, such as anencephaly, duodenal atresia, jejunal atresia, and tracheoesophageal fistula. This report confirms that suspicion. It is believed that the bilirubin which enters the amniotic fluid returns to the fetal circulation and subsequently to the placenta by fetal swallowing and absorption from the fetal gastrointestinal tract.’ In cases of upper intestinal obstruction in the fetus, this amniotic fluid clearance of indirect bilirubin is impeded, with resulting abnormal AOD rises in amniotic fluid. To our knowledge, this is the first reported case of abnormal amniotic fluid AOD at 450 rnp with evidence of fetal duodenal atresia. The recently increasing incidence of amniocentesis for various reasons will undoubtedly create situations in which similar findings are observed, and, if so, the suspicion of fetal abnormalities should be raised in the absence of isoimmunization. Investigations done after delivery confirmed the absence of intrauterine or extrauterine hemolysis. The mild hyperbilirubinemia observed in this infant was the result of prematurity. Upper intestinal obstruction in the fetus may cause abnormal amniotic fluid spectrophotometric findings, and this should be taken into account when management of such cases is planned. Intrauterine transfusions in these cases are unnecessary and may be dangerous.

84 ESTIMATION OF FETAL LUNG MATURITY AND GESTATIONAL AGE BY AMNIOTIC FLUID PARAMETERS

This study correlates some parameters for gestational age estimation with amniotic fluid data of fetal lung maturity, obtained in the third trimester of pregnancy. Eighty three amniotic fluid samples obtained from 47 complicated pregnancies were processed. The parameters studied were: a) Amniotic fluid spectrophotometry, b) Percentage of fat cells in amniotic fluid c) Gestational age according to amniotic fluid parameters, d) Lung surfactant in amniotic fluid (Clement's test), e) L/S ratio in amniotic fluid, f) Gestational age determined by examination of the neonate. A statistically significant correlation was found between Clement's test and percentage of fat cells in amniotic fluid, increase in optical density, and estimate of gestational age by amniotic fluid parameters. On the other hand, when the fat cells and gestational age by amniotic fluid parameters, no statistically significant relationship was found. It is stressed that special care should be taken in those cases in which parameters for gestational age estimation indicate fetal maturity and those of fetal lung maturity are in disagreement. If pregnancy is interrupted, the infant might develop respiratory distress syndrom (RDS), the main cause of morbi-mortality in the neonatal period.

CONTINUOUS-FLOW PLASMAPHERESIS IN MANAGEMENT OF SEVERE RHESUS DISEASE

Eight patients with severe rhesus disease and expected fetal loss were treated by intensive plasmapheresis using a continuous-flow cell separator. Plasmapheresis was started at 16-27 weeks' gestation, and continued until planned intrauterine transfusion or until the infant was delivered or the rhesus disease became uncontrolled again. Altogether 24 to 2371 of plasma was exchanged over periods ranging from seven to 16 weeks. In seven of the eight patients the anti-D concentration fell during the period of plasmapheresis. Amniotic fluid spectrophotometry values remained below those recorded in the preceding pregnancy in six out of seven women. In five patients an attempt was made to control the rhesus disease by plasmapheresis alone, and two of these women delivered infants who survived. In the other three cases the infants died, one from the idiopathic respiratory distress syndrome and the other two in utero. These preliminary findings suggest that intensive plasmapheresis with a cell separator may reduce fetal haemolysis is delivered. Nevertheless, plasmapheresis may best be used to reduce haemolysis until intrauterine transfusions may be given more safely after 30 weeks' gestation.

The predictive value of amniotic fluid spectrophotometry

Amniotic fluid spectrophotometry is the most accurate tool available in management of the Rh (D) sensitized pregnancy. The most important findings from our experience with 685 amniocenteses from 367 pregnancies would appear to be: (1) the importance of amniocentesis at low titer and (2) the value of frequent serial examinations. Comparison of certain techniques designed to estimate amniotic fluid bilirubin content reveals the singular superiority of the standard Liley method.

Amniotic fluid spectrophotometry, urinary estrogen estimations, and intrauterine transfusion in severe Rh isoimmunization

Amniotic fluid spectrophotometry, urinary estrogen levels, and intrauterine transfusion were utilized in the management of 11 severely Rh-isoimmunized pregnancies. Four infants survived. Three deaths were directly related to the transfusion procedure, and the clinical and biochemical data suggested that the remainder were moribund at the time of initial therapy. A modification of the Liley method of amniotic fluid analysis is presented in which bilirubin is reported as milligrams per cent with a semilogarithmic scale. A rapid estrogen assay, taking 6 hours, was carried out and found to relate well to bilirubin levels. The estrogen excretion curve is the only useful method for fetal assessment following intrauterine transfusion, and stable or rising levels give the clinicians confidence to carry the pregnancy closer to term. Falling levels of urinary estrogens, even if still within normal limits, indicate fetal deterioration, except immediately after transfusion when the fall may be due to fetal trauma.

Factors in prenatal prognosis of hemolytic disease of the newborn due to Rh immunization

Features of the obstetric history, antibody titers, and amniotic fluid spectrophotometry were examined in pregnant women with rhesus isoimmunization to ascertain their relative value in predicting the severity of hemolytic disease in the newborn. Among 17,420 pregnant women, rhesus isoimmunization was found in 158 cases with hemolytic disease of the newborn in 132 cases of varying severity including 24 perinatal deaths. The accuracy of predictions based upon features of the obstetric history and antibody titers was contrasted against predictions made from examination of the amniotic fluid. The use of the obstetric history and antibody titrations in predicting the fetal involvement was not as reliable as amniotic fluid analysis and both under and over assessment of the severity of the hemolytic process in the baby were seen. These features nevertheless remain of value in indicating pregnant women in whom rhesus isoimmunization has occurred and in whom a severely affected baby or perinatal death may occur. The conditions under which this may occur are described and these are also the conditions which become indications for amniocentesis and examination of amniotic fluid for changes in optical density at 450 mμ. It was found that amniotic fluid analysis besides being of increased accuracy, allowed greater confidence in the identification of severely affected babies and gave great assistance in the assessment of the exact timing for interruption of pregnancy. Without its use the indications for more radical therapeutic measures are inadequately defined. The natural outcome of pregnancies regarded as exceptionally high risk cases was examined and showed that the majority of babies survived and a few appeared less affected than in previous pregnancies.

Amniotic fluid spectrophotometry.

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Spectrophotometric analysis of amniotic fluid: Direct assessment of fetal status in the isoimmunized pregnancy

Forty-two pregnancies with various types of isoimmunization have been evaluated by direct spectrophotometry of amniotic fluid. The 450 mμ peak was plotted against the week of gestation in which the fluid was obtained. The resultant graph was arbitrarily divided into three zones. A high degree of correlation exists between the zone of the 450 mμ peak and the severity of the fetal hemolytic process. The results of this study indicate that amniotic fluid analysis is a safe procedure, and provides a reliable guide to fetal status in utero and the need for premature delivery in the isoimmunized pregnancy.A plan of management for the isoimmunized pregnancy is presented.