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Objectives To document the maternal and fetal cord blood levels of human epididymis protein 4 (HE-4) in term and preterm newborns in order to investigate the possible physiological role of HE-4 in fetal lung development. Methods This cross-sectional study was conducted in a university-affiliated hospital between April 2018 and September 2018. The study population consisted of cesarean section (C-section) deliveries after 24 weeks of pregnancy. Both maternal and umbilical cord HE-4 levels (mHE-4 and uHE-4, respectively) were measured using chemiluminescent microparticle immunoassay. Amniotic fluid was sampled from each case to determine the lamellar body count (LBC) as the gold standard test for lung maturation. All the parameters, including the uHE-4 levels, were compared between the term delivery (≥37 weeks) (n=52) and preterm delivery (24–37th weeks) (n=30) groups. The best cut-off value of uHE-4 was calculated for fetal lung maturity. Results There were no statistically significant differences between the groups regarding the demographic data. The mHE-4 levels did not statistically significantly differ between the groups (p>0.05) whereas the uHE-4 level of the preterm newborns was significantly higher than that of the term newborns (p Conclusions Although the exact physiological role of HE-4 has not yet been elucidated, this preliminary study supports the idea that HE-4 plays a role in fetal lung maturation to some extent.

Made available in DSpace on 2021-06-25T10:58:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01. Added 1 bitstream(s) on 2021-07-15T14:35:56Z : No. of bitstreams: 1 S0100-736X2020001201039.pdf: 3041931 bytes, checksum: 9b717136f14b98809111f44afce14c21 (MD5) The aim of this study was to evaluate the lung maturity of premature and full-term lambs by analyzing amniotic fluid using the following methods: Clements test, Nile blue cytology test, hematoxylin-Shorr stain, lamellar body count, and radiographic tests. The use of these methods is intended to identify high-risk newborns and provide immediate clinical intervention after birth. Altogether, 56 animals (24 ewes and 32 lambs) were included in the study and divided into 3 groups. Group I consisted of 8 ewes that were at approximately 145 days of gestation; this group delivered 10 lambs naturally. Group II consisted of 8 ewes that were at 138 days' gestation; this group delivered 11 lambs by cesarean section. Group III consisted of 8 ewes at 138 days' gestation; this group was administered intramuscular dexamethasone (16mg/animal) 36 hours prior to a cesarean section. Group III delivered11 lambs. Cytological tests were performed using a microscope with a maximum magnification of 1000x, while the Clements test was visually observed by one of the researchers. Amnioticfluid lamellar body counts were measured using transmission electron microscopy. Among the staining methods, hematoxylin-Shorr was reliable, and Group III had a greater number of orangeophilic cells when compared to Group II, probably due to corticoid administration. The Clements test showed pulmonary maturity in approximately 20% of Group I lambs and Group II showed 9.1% of bubbles; however, Group III had the highest pulmonary maturity percentage (36.4%). The lamellar bodies were measured, and all groups had sizes between 0.019 and 0.590µm. Radiographic evaluation revealed that the majority of lambs presented some level of pulmonary radiodensity, indicating an acinar pattern at birth. These results are in line with the expectations of each group. We found that the normal group showed greater pulmonary maturity, whereas Group II presented pulmonary immaturity, which is expected because this group comprised lambs born prematurely and Group III showed pulmonary. Graduate Program in Animal Science Departamento de Clínica Cirurgia e Reprodução Animal Faculdade de Medicina Veterinária Universidade Estadual Paulista Júlio de Mesquita Filho (Unesp) Campus Araçatuba, Rua Clóvis Pestana 793, Jardim Dona Amélia Faculdade de Ciências Agrárias Andradina (FCAA) Fundação Educacional de Andradina (FEA), Rua Amazonas 571 Universidade Federal de Mato Grosso do Sul (UFMS) Cidade Universitária, Av. Costa e Silva s/n, Pioneiros Veterinarian Universidade Federal de Juiz de Fora (UFJF) Campus Universitário, Rua José Lourenço Kelmer s/n Universidade Federal de Juíz de Fora (UFJF) Campus Universitário, Rua José Lourenço Kelmer s/n Graduation in Veterinary Medicine Faculdade de Medicina Veterinária Universidade Estadual Paulista Júlio de Mesquita Filho (Unesp) Campus Araçatuba, Rua Clóvis Pestana 793, Jardim Dona Amélia Departamento Clínica Cirurgia e Reprodução Animal Faculdade de Medicina Veterinária Universidade Estadual Paulista Júlio de Mesquita Filho (Unesp) Campus Araçatuba, Rua Clóvis Pestana 793, Jardim Dona Amélia Graduate Program in Animal Science Departamento de Clínica Cirurgia e Reprodução Animal Faculdade de Medicina Veterinária Universidade Estadual Paulista Júlio de Mesquita Filho (Unesp) Campus Araçatuba, Rua Clóvis Pestana 793, Jardim Dona Amélia Graduation in Veterinary Medicine Faculdade de Medicina Veterinária Universidade Estadual Paulista Júlio de Mesquita Filho (Unesp) Campus Araçatuba, Rua Clóvis Pestana 793, Jardim Dona Amélia Departamento Clínica Cirurgia e Reprodução Animal Faculdade de Medicina Veterinária Universidade Estadual Paulista Júlio de Mesquita Filho (Unesp) Campus Araçatuba, Rua Clóvis Pestana 793, Jardim Dona Amélia

Objective During the last decade, guidelines published by the American College of Obstetricians and Gynecologists (ACOG) and Society for Maternal Fetal Medicine (SMFM) have emphasized an increasingly limited role for fetal lung maturity (FLM) testing. As a reference laboratory for FLM testing, we were therefore interested in determining the impact of changing guidelines on our test volumes. Methods We retrospectively reviewed FLM test volume data from 2006 to 2016 for the following FLM assays: lecithin/sphingomyelin ratio, phosphatidylglycerol , disaturated lecithin , and lamellar body count. Results We found that there was a precipitous decline in test volumes from 2006 to 2016; our analysis led us to discontinue providing reference laboratory FLM testing in 2016 given the very low volumes. Conclusions The 2019 ACOG guidelines now state that FLM testing no longer has clinical utility. Therefore, clinical laboratory directors should meet with obstetrics providers to discuss discontinuation of FLM testing at their institutions.

Background It is not known if the endogenous surfactant pool available early in life is associated with the RDS clinical course in preterm neonates treated with CPAP. We aim to clarify the clinical factors affecting surfactant pool in preterm neonates and study its association with CPAP failure. Methods Prospective, pragmatic, blind, cohort study. Gastric aspirates were obtained (within the first 6 h of life and before the first feeding) from 125 preterm neonates with RDS. Surfactant pool was measured by postnatal automated lamellar body count based on impedancemetry, without any pre-analytical treatment. A formal respiratory care protocol based on European guidelines was applied. Clinical data and perinatal risk factors influencing RDS severity or lamellar body count were real-time recorded. Investigators performing lamellar body count were blind to the clinical data and LBC was not used in clinical practice. Results Multivariate analysis showed gestational age to be the only factor significantly associated with lamellar body count (standardized β:0.233;p = 0.023). Lamellar body count was significantly higher in neonates with CPAP success (43.500 [23.750–93.750]bodies/μL), than in those failing CPAP (20.500 [12.250–49.750] bodies/μL;p = 0.0003).LBC had a moderate reliability to detect CPAP failure (AUC: 0.703 (0.615–0.781);p

INTRODUCTION Predicting maturity of the foetal lung is extremely important in many obstetric situations as respiratory distress syndrome caused by surfactant deficiency remains one of the leading causes of neonatal morbidity and mortality. The need for predicting the foetal lung maturity by means of an accurate test which is done rapidly and available in majority of centres was the objective for this study. AIM To find out the optimum lamellar body count which correlates with foetal lung maturity and to compare the lamellar body count with shake bubble test. MATERIAL AND METHODS This prospective study was designed to evaluate the lamellar body count by standard haematology cell counter that is coulter counter and compare it with shake bubble test. Both the tests were done on 100 amniotic fluid samples in women with gestational age more than 28 weeks. Patients recruited were those who were sure of their last menstrual period (LMP), who were in active labour, and likely to deliver within 72 hours of collection of sample. Amniotic fluid samples obtained by transabdominal amniocentesis or by aspirating the forewaters per vaginum. Both shake bubble test and lamellar body count were done on the sample. RESULTS Lamellar body counts ranged from 10,000-2,43,000/microlitre and had a linear relationship with gestational age. The cut-off level of 30,000/microlitre was considered to be optimum to predict foetal lung maturity. Sensitivity and negative predictive value of lamellar body count at 30,000/microlitre and shake bubble test were comparable at 91.7%/91.7% and 97.3/96.6% respectively whereas with respect to specificity and positive predictive value, lamellar body count was superior to shake bubble test at 93.4%/73.7% and 81.5%/50%. CONCLUSION Lamellar body count is a rapid, inexpensive, simple and more reliable test to assess foetal lung maturity

Objective: The current study aims to compare the ultrasonographic evaluation of fetal lung Gray-level histogram width (GLHW) ratio with an amniotic fluid lamellar body count (LBC) in the prediction of fetal lung maturity. Methods: A prospective cohort study was conducted at a tertiary University Hospital in the period between May 1, 2017 and March 31, 2018. The study included pregnant women with a single fetus at ≥37 weeks of gestation scheduled for delivery by elective cesarean section (CS). Ultrasound evaluation was performed for assessment of the fetal lung to liver GLHW ratio to predict lung maturity. Lamellar body count was determined from an amniotic fluid sample obtained via amniotomy during CS. The lamellar body count for this sample was measured using a hematology analyzer. These data were further compared to Apgar scores at 1 and 5 minutes after delivery to assess the condition of the newborn immediately after birth, the degree of respiratory distress syndrome (RDS) and the need for resuscitation. Results: One hundred twenty women and their neonates were included in the study. There was a statistically significant decrease in the levels of both GLHW and LBC among those neonates that showed distressed respiration after Apgar testing as compared with those who did not show similar distress, with p-value

Background Twin pregnancies have a higher rate of preterm births, making precise prediction of neonatal respiratory disorders essential. We herein examined the amniotic lamellar body count (LBC) and found it to be an accurate predictor of respiratory disorders in twin pregnancies. Methods Five hundred fourteen amniotic fluid samples, comprising 132 dichorionic twin (DCT) and 125 monochorionic twin (MCT) gestations, were obtained at cesarean section performed at 29 to 38 gestational weeks. Samples were analyzed immediately without centrifugation. Results There were 26 neonates (5.1%) with respiratory distress syndrome (RDS) and 43 (8.4%) with transient tachypnea of the newborn (TTN). The LBC in neonates with TTN (5.12 × 104/μl) was between the counts in RDS (1.26 × 104/μl) and controls (10.6 × 104/μl), which differed significantly. Twin concordance rates were significantly higher for TTN in MCT gestations than DCT gestations (p = 0.003) and delta LBC value was significantly smaller in MCT (3.15 ± 0.4 × 104/μl) than DCT (5.17 ± 0.5 × 104/μl) gestations (p = 0.003). Conclusions The amniotic LBC is useful for predicting respiratory disorders, including RDS and TTN, in twin pregnancies. The data in this study may indicate a genetic predisposition to TTN among MCTs.

Human lysophosphatidylcholine acyltransferase 1 (hLPCAT1) is a protein which helps produce surfactant in the fetal lung. We previously reported that levels of cell-free fetal mRNA for hLPCAT1 in amniotic fluid are correlated with lamellar body count (LBC) (r2=0.93). This short communication demonstrates that fetal hLPCAT1 mRNA is also present in maternal blood. Its quantity also correlates with amniotic fluid LBC (r2=0.81). Research in maternal plasma hLPCAT1 may assist in understanding fetal and placental maturational processes.

Respiratory distress syndrome causes morbidity and mortality of the newborn and is most often associated with premature birth. Laboratory testing can be helpful in establishing fetal lung maturity (FLM) status in situations when premature delivery may be necessary. In addition, the rising incidence of late-preterm births at >34 and =50 k/mm3.

The aim of this study was prediction the fetal lung maturity by ultrasonic markers and comparison by lamellar body count and fetal outcome.A prospective Longitudinal study Department of perinatology of performed Emam Khomeini hospital and Mirza Kochak Khan Hospital in Tehran, Iran from March 2013 to January 2014. 100 pregnant women (37-40 weeks of gestation) who were admitted for elective cesarean section and referred for an obstetric ultrasound scan at the same day of their elective cesarean section were included. Scanning with linear ultrasound with convex transducer frequency of 3.5 MHZ was utilized to measure the biparietal diameter, Amniotic fluid vernix and placental grading. Statistical analysis was performed using Spss version 20. Validity of the indicators compared with lamellar body count and fetal outcome.In this study, from 100 patients under study, 8 cases were hospitalized in NICU (neonatal intensive care unit) which all of them had LAMELAR BODY COUNT 14000 (10000-14000). There were 6 boys and 2 girls. In this study, there was no perinatal mortality.In study we used ultrasonic marker of fetal lung maturity and related this to lamellar body count and neo natal outcome. The ultrasonic marker of fetal lung maturity can reduce mortality and morbidity in neonate.

The aim of this study is to evaluate the performance of amniotic fluid lamellar body count (LBC) on the timing of elective caesarean delivery (CS) at ≥ 39 weeks. After allocating the study group (group I, transient tachypnoea of newborn (TTN), n = 14), an age-matched control group (group II, no TTN, n = 79) was selected for amniotic fluid LBC analysis. The median amniotic fluid LBC levels in group I were significantly lower than in the control group. Furthermore, the median values of mean lamellar body volume, median lamellar body distribution width and lamellar bodycrit in group I were also significantly lower than in group II. The best amniotic fluid LBC value to predict TTN was 40.15 × 10(3)/μl, with 82.3% sensitivity and 64.3% specificity. The favourable sensitivity and specificity values to predict the TTN for amniotic fluid LBC may suggest using it as an elective caesarean delivery-time scheduling marker.

Objectives To evaluate surfactant content and function through the lamellar body count (LBC) and stable microbubble test (SMT) in mechanically ventilated infants with severe acute viral bronchiolitis. Study design Controlled cross-sectional study of 32 infants receiving mechanical ventilation: 16 with a diagnosis of acute viral bronchiolitis and 16 with normal lungs. Tracheal fluid was collected and LBC was performed in an automated cell counter. Samples were kept frozen and thawed for testing. At the time of analysis, samples were diluted in a dithiothreitol solution, vortexed for 10 seconds, and aspirated by the cell counter. SMT was performed using the Pattle technique. Results In the bronchiolitis group, the median (IQR) LBC was significantly lower than in the control group: 130 000 (61 250-362 250) vs 518 000 (180 250-896 000) lamellar bodies/μL; P = .003. Median (IQR) SMT values were also significantly lower in the bronchiolitis group: 10 (2-13) vs 400 (261-615) microbubbles/mm 2 ; P Conclusions Infants with acute viral bronchiolitis have reduced surfactant content and function. We speculate that these simple tests may be useful to identify infants with bronchiolitis who would benefit from surfactant replacement therapy.

Respiratory distress syndrome is a major cause of neonatal morbidity and mortality that is most commonly caused by a deficiency in lung surfactant in premature infants. Therefore, laboratory tests were developed to measure the presence and/or concentration of lung surfactant in amniotic fluid in order to estimate maturity of the fetal lung. Although these tests were once widely employed, their utilization by physicians has decreased in recent years. Several studies have shown that demonstration of a mature fetal lung index by antenatal testing does not improve neonatal outcomes. Instead, decreased respiratory and nonrespiratory morbidities are most highly correlated with gestational age of the fetus. Therefore, fetal lung maturity testing may have passed the point of being clinically useful.

Objective: The study was designed to acquire the cut-off value for lamellar body count and its role in predicting the presence of Respiratory Distress Syndrome (RDS) in pregnancy with gestational age above 28 weeks. Method: Amniotic fluid specimens were collected by amniotomy during cesarean section from women with gestational age above 28 weeks. A haematology analyzer (Advia 120) was used to determine the lamellar body counts. We also performed foam stability test and observed the development of respiratory distress syndrome. Receiver operating characteristics curve was estimated to assess the threshold of lamellar bodies count that may predict the presence of Respiratory Distress Syndrome. Result: Fifty nine specimens were collected from woman with 29 - 42 weeks gestational age. The incidence of Respiratory Distress Syndrome was 15.3%. Area under the curve for lamellar body count was 0.94. Lamellar body count, with the best cut-off point of 50,000 cell/μl had sensitivity 89% and specifity 92% for predicting the presence of RDS, while the sensitivity of foam stability test was 67% and specificity was 90%. The negative predictive value of the lamellar body count was 98% slightly better than the negative predictive value of the foam stability test 94 %. Conclusion: Although both test are good predictor of RDS, lamellar body count has higher sensitivity and specificity. It also has more advantages as it only requires small amount of sample, fast, easy and more objective. [Indones J Obstet Gynecol 2012; 36-4: 176-80] Keywords: foam stability test, lamellar body, respiratory distress syndrome

Objective To determine the diagnostic accuracy of the surfactant adsorption test (SAT) as a predictor for the need for surfactant replacement therapy in neonates with respiratory distress syndrome (RDS). Study design Amniotic fluid samples were collected from 41 preterm neonates with RDS treated with continuous positive airway pressure (CPAP) and 15 healthy control term neonates. Purified porcine surfactant served as a further control. Lamellar bodies and lung ultrasound score were also measured in a subset of the neonates treated with CPAP. Surfactant was administered according to the European guidelines, and clinical data were collected prospectively. Surfactant activity was measured as adsorption at the air/liquid interface and given in relative fluorescent units (RFU). Results Surfactant activity differed among native porcine surfactant (median, 4863 RFU; IQR, 4405-5081 RFU), healthy term neonates (median, 2680 RFU; IQR, 2069-3050 RFU), and preterm neonates with RDS (median, 442 RFU; IQR, 92-920 RFU; P .0001). The neonates who failed CPAP had lower surfactant activity compared with those who did not fail CPAP (median, 92 RFU; IQR, 0-315 RFU vs 749 RFU; IQR, 360-974 RFU; P = .0002). Differences between groups were more evident beyond 20-30 minutes of fluorescence; the 30-minute time point showed the highest area under the curve (0.84; P .001) and the best cutoff level (170 RFU; specificity, 72%; sensitivity, 96%) for the prediction of CPAP failure. Surfactant activity at 30 minutes was significantly correlated with lamellar bodies ( r = 0.51, P = .006) and lung ultrasound score ( r = -0.39, P = .013). Conclusion This technique has the potential to be developed into a fast, simple-to-interpret clinical test. The SAT can reliably identify preterm infants with subsequent CPAP failure and shows promise as a screening test for surfactant replacement in preterm neonates.

Objective To evaluate surfactant production and function in term neonates with transient tachypnea of the newborn (TTN). Study design Samples of gastric aspirates collected within 30 minutes of birth from 42 term newborns with gestational age ≥37 weeks (21 patients with TTN and 21 control subjects), delivered via elective cesarean delivery, were analyzed with lamellar body count and stable microbubble test. Results Results of lamellar body counts and stable microbubble tests were significantly lower in the TTN group than in control subjects ( P = .004 and .013, respectively). Lamellar body counts were significantly lower in infants with TTN requiring oxygen for ≥24 hours after birth than in infants requiring oxygen for P = .029). When the cutoff point was 48 hours, the stable microbubble count was significantly lower in the group requiring oxygen for ≥48 hours than in the group requiring oxygen for P = .047). Conclusions Term infants with TTN had low lamellar body counts associated with decreased surfactant function, suggesting that prolonged disease is associated with surfactant abnormalities.

The lamellar body count (LBC) represents an alternative method to the TDx-FLM II (Abbott Laboratories, Abbott Park, IL), which is planned to be discontinued, for assessing fetal lung maturity. Our objective was to validate the LBC on 3 hematology analyzers (Coulter LH 750 and Coulter Ac·T diff2, Beckman Coulter, Brea, CA; and Sysmex XE-2100, Sysmex, Mundelein, IL) to serve as a template for other laboratories attempting to perform in-house validation. Intra-assay and interassay coefficients of variation ranged from 1.7% to 21.8% and 1.9% to 7.1%, respectively, and all analyzers demonstrated excellent linearity. Whole blood and meconium were shown to interfere with LBCs, and specimens with these contaminants should be tested using phosphatidyl glycerol. With a TDx-FLM II cutoff of 55 mg/g or more and an LBC cutoff of 50,000/μL or more for maturity, concordance between the TDx-FLM II and the LBC on all instruments was poor (

Background: Lamellar bodies are present in amniotic fluid and their quantity increases with increased gestational age. Preterm premature rupture of the membranes (P-PROM) is one of the most common complications of pregnancy and is a major cause of preterm deliveries and thus the important cause of RDS. Fetal pulmonary maturity can be assessed by direct or indirect measurement of surfactant phospholipids secreted by the fetal lungs into amniotic fluid. Lamellar body count (LBC) has been introduced as an alternative to other methods.Methods: The study’s prime aim is to establish LBC as a predictor of RDS in P-PROM. We included pregnant women with P-PROM and gestational age between 28 weeks and 37 weeks and singleton live pregnancy. The lamellar body counting from amniotic fluid was done with the use of a standard hematology cell counter, sysmex KX-21. There was statistically significant co-relation between lamellar body count and period of gestation (by applying ANOVA).Results: Lamellar body counts were significantly less in cases of RDS as compared to non RDS cases.Conclusions: LBC count was selected among all other tests because the test can be performed with equipment found in most clinical analysis laboratories and is reliable in predicting fetal lung maturity.

Objective. A lamellar body count (LBC) ≥50,000/μl is suggested to document fetal lung maturity (FLM). We sought to determine the LBC threshold for FLM with the Cell-dyn 4000 hematology analyser.Methods. We queried our database for patients who underwent LBC testing from 2001 to 2007. Included were deliveries between 35 and 38 weeks gestation with testing ≤7 days from delivery. We excluded twins, anomalies and cases of ruptured membranes. Data were analysed for sensitivity and specificity of predicting respiratory distress syndrome (RDS) and plotted on a receiver operating characteristic curve.Results. There were 209 patients meeting study criteria. Of these, 120 had diabetes. Five neonates experienced RDS, all born to non-diabetic mothers with LBC values ≤72,000/μl. At this value the sensitivity is 100%, false positive rate 18% and the p value is 0.0146.Conclusion. Our results question the 50,000/μl threshold and demonstrate the need for hematology analyser specific thresholds.

Background The amniotic lamellar body count (LBC) is useful for predicting respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN) in twin pregnancies. However, the risk of neonatal respiratory complications varies with gestational age (GA). We herein created a model to predict the risk for RDS and TTN using GA and the LBC in twin pregnancies. Methods Six hundred thirty-two amniotic fluid samples, comprising 169 dichorionic twin (DCT) and 147 monochorionic twin (MCT) gestations, were obtained at Cesarean section. The samples were analyzed immediately without centrifugation. A logistic regression model including the LBC and GA was used to develop the prediction model for RDS/TTN. Results There were 101 neonates (16.0%) with RDS/TTN. The GA and LBC were significant independent factors affecting RDS/TTN. According to the logistic regression model, we determined the probability of RDS/TTN given the values of GA and the LBC. The overall diagnostic accuracy for predicting neonatal RDS/TTN using GA and the LBC was higher than the use of the LBC alone. Conclusions GA-specific LBC cutoffs for the risk assessment of neonatal RDS/TTN have been considered to be more accurate in twin pregnancies. Our findings provide valuable, new information for the management of twin pregnancies.

Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is required in the biosynthesis of pulmonary surfactant. This short communication describes our assessment of LPCAT1 mRNA levels in human amniotic fluid. We found a direct correlation between LPCAT1 mRNA copies and the amniotic fluid lamellar body count (LBC). This finding corroborates an association between LPCAT1 and surfactant phospholipid biosynthesis in humans. It may provide a model for future research in perinatal medicine.

Fetal lung maturity assessment in twin pregnancy has been discussed, but is still controversial. The purpose of this study is to predict the occurrence of respiratory distress syndrome (RDS) using lamellar body count (LBC) and analyze the validity of LBC for fetal lung maturity assessment in twin pregnancy. Three-hundred two amniotic fluid samples were obtained at cesarean section from 29 to 38 weeks of gestation. Samples were analyzed immediately with no centrifugation and the number of lamellar bodies was counted using a platelet channel on the Sysmex SF-3000. There were 18 neonates (6.0%) suffering from RDS. An LBC cut-off value of 2.95 × 104/μL resulted in 91.5% sensitivity and 83.3% specificity for predicting RDS. This cut-off value for predicting RDS was the same as that in singleton pregnancy. Moreover, the median LBC value in RDS cases was significantly lower than in non-RDS cases (1.50 ± 1.1 × 104/μL vs. 10.6 ± 7.5 × 104/μL; p < .001). This is the first report on the validity of LBC in twin pregnancy and also the largest study on fetal lung maturity assessment in twin pregnancy. An LBC value of >2.95 × 104/μL means reassuring findings for RDS even in twin pregnancy. We believe the data in this study provide valuable, new information for the management of twin pregnancies.

Objective To use amniotic fluid (AF) lamellar body count (LBC) to assess the influence of pre-eclampsia and associated pathologic conditions on fetal lung maturity (FLM). Methods A prospective study was conducted to analyze 378 AF samples containing 5 mL of AF from 306 singleton pregnancies at 26–39 weeks. Stratified by gestational age groups, pregnancies were categorized as follows: pre-eclampsia (n = 25); intrauterine growth restriction (IUGR) (n = 74); pre-eclampsia and IUGR (n = 63); and control (n = 144). Amniotic fluid LBC in each group was estimated and medians were compared for defined gestational age periods. Statistical analyses were performed via non-parametric tests. Results Between 31 and 33 weeks, significantly lower median LBCs were found in the pre-eclampsia group than in the IUGR group (P = 0.022) and in pregnancies with both entities (P = 0.031). Between 34 and 36 weeks, there were significantly lower median LBCs in the pre-eclampsia and the pre-eclampsia/IUGR groups than in the IUGR group (P = 0.026 and P = 0.004, respectively), as well as in the pre-eclampsia/IUGR group compared with the control group (P = 0.04). Conclusion Significantly lower LBCs in pre-eclamptic pregnancies between 31 and 36 weeks of gestation indicate delayed FLM associated with pre-eclampsia.

Objectives: To determine the number of lamellar bodies in the amniotic fluid indicating fetal lung maturity and to define the effectiveness of a diagnostic test in a healthy pregnant population. Methods: The study took place at the Hospital General de Zona #16 Centro Medico Nacional del Instituto Mexicano del Seguro Social. Torreon, Coahuila, Mexico, where 264 pregnant women were followed-up from August 1997 to October 1998. The women presented in labor between 26 and 41 weeks of gestation. Amniotic fluid was obtained during cesarean section or from the vaginal pool and lamellar bodies were counted without prior centrifugation in Cell-Dyn 3000's channel for blood platelets. Results were masked for neonatologists. Results: The prevalence of respiratory distress syndrome (RDS) was found to be 14.9%. At the 8200/μl threshold, sensitivity was: 15.4% (95% CI=5.9–30.5%), specificity: 99.6% (95% CI=97.5–99.9%), positive predictive value (PPV): 85.7, negative predictive value (NPV): 87.1, likelihood ratio for a negative test (LR−): 0.85, and likelihood ratio for a positive test (LR+): 85.7. At the 57 000/μl level, sensitivity was: 92.3% (95% CI=79.1–98.3%), specificity: 70.9% (64.4–76.7%), PPV: 35.6, NPV: 98.1, LR−: 0.11, and LR+: 3.17. When the cut-off point was 79 000/μl, sensitivity was: 100.0%, specificity: 43.0% (95% CI=36.5–49.8%), PPV: 23.5, NPV: 100.0, LR+: 34.3, and LR−: less than 0.001. Conclusions: Counting lamellar bodies is a quick, readily available, and very effective test.

AIMS To develop a predictive model for assessing the risk of developing neonatal respiratory morbidity using lamellar body counts (LBCs) and gestational age (GA) to provide a more patient-specific assessment. METHODS Retrospective cohort study of patients' ≥32 weeks' gestation who received amniocentesis with LBC analysis over a 9-year period. Respiratory morbidity was defined as respiratory distress syndrome, transient tachypnea of the newborn or oxygen requirement for >24 h. Logistic regression analyses were used to predict the absolute risk and odds of respiratory morbidity as a function of GA and lamellar body count. RESULTS Two hundred and sixty-seven mother-infant pairs included in the analysis with 32 cases (12.0%) of respiratory morbidity. When compared to those without respiratory morbidity, neonates with respiratory morbidity had amniocentesis performed at an earlier median GA, had lower mean birthweight and had lower median LBC (P

To determine whether meconium-contaminated amniotic fluid falsely elevates the lamellar body count in fetal lung maturity testing.Thirty mothers undergoing amniocentesis for fetal lung maturity testing were prospectively consented. A 2 mL portion of the patient's sample was mixed with a 10% meconium solution and the meconium-stained sample was then run in tandem with the patient's sample used in clinical management. Pure meconium samples without amniotic fluid were also run through the cell counter for analysis.Following meconium contamination, the lamellar body count value increased in 67% of the cases, decreased in 23% and remained the same in 10%. There were 13 test results that had "immature" values in the uncontaminated patient management sample group and nine of these (69%) became elevated to a "mature" level (a false elevation) following the addition of meconium. All of the 10 pure liquid meconium samples devoid of amniotic fluid processed by the cell counter identified and quantified some particle the size of platelets.The lamellar body count test result is not reliable in meconium-stained amniotic fluid specimens. There is some unknown particle found in meconium that is the size of platelets/lamellar bodies that can falsely elevate the test result. Currently, the only reliable fetal lung maturity test in meconium-stained amniotic fluid is the presence of phosphatidylglycerol.

Objective To compare the performance of the lecithin/sphingomyelin ratio and the lamellar body count in the prediction of neonatal respiratory distress syndrome. Design Meta-analysis. Sample Six studies reporting on the performance of both the lecithin/sphingomyelin ratio and the lamellar body count published between January 1966 and August 1999. Methods We performed a computerised MEDLINE search to identify articles published on the subject. For the six selected studies, prevalence of respiratory distress syndrome and sensitivity and specificity of the tests in the prediction of respiratory distress syndrome were calculated, and overall performance was assessed by constructing summary receiver–operating characteristic curves. Results The constructed summary receiver–operating characteristic curves showed the lamellar body count to perform slightly better than the lecithin/sphingomyelin ratio in the prediction of respiratory distress syndrome (P= 0.13). Conclusions Since the lamellar body count can be performed quickly and since it is less expensive than the lecithin/sphingomyelin ratio, we recommend the former as the test of first choice in the assessment of fetal lung maturity.

Objective: To compare lamellar body counts with the lecithin/sphingomyelin ratio and phosphatidylglycerol analysis in terms of assessment of risk of respiratory distress syndrome (RDS). Methods: Lamellar body counts, lecithin-sphingomyelin ratios (L/Ss), and phosphatidylglycerol levels were assessed in 1611 amniotic fluid samples obtained at four clinical sites from pregnant women whose fetuses were at risk for RDS. Cases in which delivery occurred within 72 hours of sample collection (n = 833) were analyzed. Specific cutoffs for predicting the likelihood of RDS for both the lamellar body count and the L/S had been derived previously at each of the clinical sites based on receiver operating characteristic curves using unrelated samples, whereas phosphatidylglycerol was reported as either mature (present) or immature (absent). Standard clinical and radiographic criteria were used to diagnose RDS, and the diagnosis was confirmed by review of newborn records. Results: One hundred (12.0%) of the 833 infants delivered within 72 hours of sample collection developed RDS. The negative predictive value of the lamellar body count (97.7%) was similar to that of the L/S (96.8%) and slightly better than that of phosphatidylglycerol analysis (94.7%) (P = .048). The lamellar body count performed as well as phospholipid analysis irrespective of gestational age or patient population. Conclusion: The lamellar body count compares favorably with traditional phospholipid analysis as an assay for assessment of fetal lung maturity. Lamellar body counts are preferable because they are faster, more objective, less labor intensive, less technique dependent, and less expensive and because they can be performed with equipment available in every hospital laboratory.

Objective: To create a highly specific cascade testing scheme for fetal lung maturity using the lamellar body count, lecithin/sphingomyelin ratio (L/S), and phosphatidylglycerol. Methods: A nondedicated hematology analyzer (Sysmex NE 1500, Toa Medical Electronics, Los Angeles, CA) was used to determine the lamellar body counts of 209 unspun amniotic fluid specimens. Maximally specific lamellar body count cutoffs for biochemical maturity and immaturity were determined using receiver operating characteristic curves. Biochemical lung maturity was defined as either a mature L/S ratio or phosphatidylglycerol. Biochemical lung immaturity was defined as both an immature L/S ratio and an immature phosphatidylglycerol. Results: A lamellar body count of less than 8000 (n = 17) was 100% specific for biochemical lung immaturity (positive predictive value = 100%, negative predictive value = 86%). A lamellar body count of greater than 32,000 was 98% specific for biochemical lung maturity (positive predictive value = 99%, negative predictive value = 63%). Conclusion: Testing only specimens where the lamellar body count was greater than 8000 and less than or equal to 32,000 for the L/S ratio and phosphatidylglycerol would preclude the need for 76% of all L/S and phosphatidylglycerol assays. Because the lamellar body count is quick, simple, and universally available, it could serve as an extremely cost-effective screening test for fetal lung maturity.

Despite the development of artificial surfactant and advances in respiratory support, respiratory distress syndrome (RDS) remains a major clinical concern. The relatively low prevalence of RDS requires test methods with very high diagnostic sensitivity and specificity for fetal lung maturity (FLM). Such methods often require sophisticated instrumentation, skilled staff, and long analytic times. This practice parameter discusses the usefulness of widely available methods and reaches several conclusions: (1) A satisfactory specimen of amniotic fluid is essential for effective laboratory assessment of FLM. (2) No test is immune from analytic interferences. (3) The lecithin/sphingomyelin (L/S) ratio or phosphatidylglycerol (PG) by thin-layer chromatography are unnecessary as obligatory panel components. (4) Either fluorescence polarization or lamellar body number density is an acceptable initial screening test. If maturity is indicated, no further testing is generally necessary. (5) If the result of the initial test in no. 4 is below but near the maturity criterion, the second rapid test usually can offer resolution; if the result is still immature, a third rapid test can be added (PG by Amniostat-FLM). (6) In the setting of poorly controlled diabetes, PG assessment by Amniostat-FLM should be performed to rule out false maturity predictions by the other rapid tests. Nevertheless, RDS will not develop in most fetuses in whom PG is not detected. (7) Clinical judgment remains the single most important criterion for fetal delivery.

Objective: To assess fetal lung maturity tests in hypertensive pregnancies and to examine the effect of glucocorticoid therapy. Methods: In a cohort study involving 68 pregnant women with hypertension, 34 received antenatal betamethasone before amniocentesis and 34 did not. Controls were 68 women with uncomplicated pregnancies, matched for gestational age at amniocentesis and fetal gender. Amniotic fluid (AF) samples were analyzed by lamellar body count, planimetric and stechiometric lecithin-sphingomyelin ratio (L/S), and presence of phosphatidylglycerol. Results: Fetal lung maturity, as determined by lamellar body counts and by planimetric L/S, was lower in hypertensive pregnancies not treated with steroids than in controls (19,600 ± 14,500 versus 39,800 ± 22,700, P < .009, and 1.9 ± 0.6 versus 3.9 ± 1.8, P < .01, respectively). In the period of 24 to 33 weeks’ gestation, the percentage of untreated pregnancies with mature lamellar body counts and mature L/S was significantly lower than that of controls (13% versus 33%, P < .001; 6% versus 40%, P < .002 and P < .003, respectively). In contrast, in patients treated with betamethasone, the percentage of cases with mature indices for both tests was not significantly different from that of controls, but was higher than that of untreated hypertensive patients (40% versus 13%, P < .001; 33% versus 6%, P < .001). Phosphatidylglycerol did not differ among groups. From 34 to 38 weeks, no difference was found in the percentage of mature cases for lamellar bodies in pregnant women with hypertension not treated with steroids in comparison with controls (68% versus 84%), nor between cases treated and controls (74% versus 84%). In the same period, no difference in L/S values was found among groups, and the percentage of cases positive for phosphatidylglycerol was lower in hypertensive pregnancies than in controls (47% versus 95%, P < .001) and was not affected by steroid treatment (37% versus 95%, P < .001). Conclusion: Fetal lung maturity, as reflected in AF tests, is delayed in hypertensive pregnant patients, and steroids increase all lung maturity indices except phosphatidylglycerol between 24 and 33 weeks’ gestation.

Objective To determine and compare the diagnostic accuracy of the lecithin/sphingomyelin (L/S) ratio and lamellar body count (LBC) in the prediction of neonatal respiratory distress syndrome (RDS). Study design A systematic review was performed to identify studies comparing either the L/S ratio or the LBC with the occurrence of RDS published between January 1999 and February 2009. Two independent reviewers performed study selection and data extraction. For each study sensitivity and specificity were calculated. Summary receiver-operating characteristics (ROC) curves, assessing the diagnostic performance of both tests, were constructed. A subgroup analysis was performed to estimate the sensitivity and specificity of the various cut-off values. Results 13 studies were included. The ROC curves of the collected data illustrate that the LBC and L/S ratio perform equally well in the prediction of RDS. Comparison of the two summary ROC curves of each test indicates that the diagnostic performance of LBC might even have a slight advantage over L/S ratio. Due to the wide cut-off range it was not possible to define specific cut-off values with the best accuracy. Conclusion We recommend replacing the L/S ratio as gold standard with the lamellar body count since the LBC is easy to perform, rapid, inexpensive, and available to all hospitals 24 h per day.

Background Pregnancies with placenta previa are significantly associated with preterm delivery and cesarean section. Therefore particular attention should be paid to the incidence of neonatal respiratory disorders in pregnancies with placenta previa. Aims The purpose of this study is to examine the relationship between placenta previa and neonatal respiratory disorders, including respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN), and to evaluate the impact of placenta previa on the amniotic lamellar body count (LBC) values. Methods We analyzed the data from 186 registered elective cesarean cases without fetal or maternal complications at 36–38 weeks of gestation. Amniotic fluid samples were analyzed immediately without centrifugation, and the LBC was measured using a platelet channel on the Sysmex XE-2100. Results RDS was present in four neonates (2.2%) and TTN in 12 neonates (6.5%). The rate of TTN was significantly higher and the LBC values were significantly lower in the placenta previa group than in the control group (P = 0.002 and P = 0.024). The adjusted odds ratio for neonatal TTN was 7.20 (95% confidence interval: 6.58–7.88) among females with placenta previa. In placenta previa, warning bleeding was a significant factor protecting against neonatal respiratory disorders (P = 0.046). Conclusions Placenta previa in itself is a risk factor for neonatal TTN. When an elective cesarean section is performed in cases with uncomplicated placenta previa, special care should be taken to monitor for neonatal TTN even at 36–38 weeks of gestation.

We examined the extent of fetal lung hypoplasia and lung maturation using the amniotic lamellar body count (LBC) in congenital diaphragmatic hernia (CDH). We obtained 30 amniotic fluid samples from human CDH cases during cesarean section. We assessed LBC, magnetic resonance imaging (MRI), and ultrasound findings for predicting the prognosis of CDH. We collected newborn amniotic fluid and lung tissue at embryonic day (E)21 from normal and nitrofen-induced CDH rats (administered 100 mg orally at E9). Amniotic LBCs in rats were measured using light microscopy. In human CDH, LBC was significantly higher in the surviving than in the deceased group (P < 0.01). A significant positive correlation was observed between LBC and percentage of fetal lung volume on MRI (P < 0.001; r = 0.716). In rats, LBC was significantly higher in controls than in CDH rats (P < 0.01) and correlated with fetal lung weight. We conclude that LBC is useful for predicting lung hypoplasia in human CDH after 35 gestational weeks and in a rat model of nitrofen-induced CDH.

Amac : Fetal akciger maturasyonunun degerlendirilmesinde en sik kullanilan testler olan lameller cisimcik sayimi ile TDxFLM testinin birbirlerine ustunluklerinin incelenmesi ve lameller cisimcik sayiminda halen netlesmeyen esik degerinin nedenlerini arastirmak. Gerec ve Yontem: Hastanemizde 1 yil icinde 56 hastadan alinan amnion sivilari 2 ayri tup ile her iki test acisindan degerlendirildi. Yenidogan bebekler test sonuclarini bilmeyen bir neonatalog tarafindan yenidogan solunum sikintisi acisindan degerlendirildi ve takip edildi. Dogum sonrasi 6 ila 8 saat icinde baslayan takipne, inleme, cekilmeler ve siyanoz gibi bulgular, 24 saat uzerinde suren oksijen ihtiyaci, oksijen kismi basinci 50mm Hg’dan daha dusuk arteryal kan gazi sonucu, klinik tablosu ile uyumlu akciger filmi bulgulari varligi yenidogan solunum sikintisi olarak kabul edildi. Bulgular: 56 yenidogandan 44 tanesinde solunum sikintisi izlenmezken, 12 tanesinde (%21.4) yenidogan solunum sikintisi tablosu gerceklesmistir. Lamellar cisimcik sayisi santrifuj edilmeden olculmesi sonrasinda deger >55000 / mm³ olan 30 hastanin hicbirinde RDS gelismemistir. Lamellar cisimcik 4 olarak tespit edildiginde, olgularin hepsini tespit etmekte, duyarliligi ve ozgullugu %100 seviyesine cikarmaktadir. Sonuc: Lameller cisimcik sayimi; hizli, pratik, kolay ulasilabilir ve maliyet etkinlik acisindan avantajlari tartisilmaz bir tani yontemidir. Farkli esik degerleri olmasinin gecerli nedenleri oldugu gozlenmektedir. Bu nedenle her klinigin kendi sinirlarini belirlemesinin gerekli oldugu sonucuna ulasilmistir. Ayrica ara degerlerde kalinan durumlarda TDxFLM testi ile ilave degerlendirme yapilmasinin duyarliligi ve ozgullugu arttirdigi belirlenmistir. Anahtar kelimeler : Solunum sikintisi sendromu; lameller cisimcik sayimi; fetal akciger maturitesi

The lamellar body count (LBC) plays a crucial role in fetal lung maturity testing. Lamellar bodies are often counted in the platelet channel of routine hematology analyzers, resulting in a rapid and inexpensive assay for fetal lung maturity. Recently, significant imprecision was noted during LBC validation on the Beckman Coulter Unicel DxH 800.The results of two Beckman Coulter Unicel DxH 800 instruments were compared to those of a Coulter LH 750 and Coulter LH 500. Three pools of amniotic fluid, commercial quality control materials, and proficiency test specimens were analyzed on all four instruments. Fifty patient specimens were also analyzed using the Coulter LH 500 and the Unicel DxH 800.The mean values and precision obtained from commercial quality control materials and proficiency test samples were comparable on all four instruments. However, many erroneously low LBC results were produced from amniotic fluid pools using both DxH 800 instruments. The erroneous values were approximately 50% lower than respective target values, occurred randomly, and affected the low, medium, and high LBC results. Inter-assay precision of the three pools ranged from 24.7 to 39.0 CV% on the DxH 800 instruments.The source of LBC errors likely involves the exclusion of smaller lamellar bodies from the counts. The DxH 800 combines new data fusion technology and mathematical algorithms to produce increased accuracy and flagging efficiency. Laboratorians should be aware that the improved specificity of the DxH 800 may preclude its use for this laboratory-developed test.

Respiratory distress syndrome (RDS) occurs in infants delivered before the completion of fetal lung maturation and remains a major cause of neonatal morbidity and mortality in premature infants (1). RDS affects approximately 1% of all live births, but 10 to 15% of all infants with a birth weight less than 2500 g (2). The risk of RDS is increased with prematurity, but is also significant in infants born by electively scheduled cesarean delivery between 38 and 39 weeks of gestation (3). Therefore, the American College of Obstetricians and Gynecologists recommends the documentation of fetal lung maturity for elective deliveries at less than 39 weeks of gestation to avoid neonatal RDS (4). There are several antenatal tests for lung maturity. Evaluation is commonly based on laboratory measurements of the concentrations of particular components of pulmonary surfactant (4-7). Most of them are either complex, expensive, or with low diagnostic efficiency (8). Amniotic fluid lamellar body count (LBC) is one among various biophysical tests, based on measuring the concentration of pulmonary surfactant in amniotic fluid (9). Lamellar bodies (LB) are storage form of surfactant within type II pneumocytes and are actively secreted into the alveolar space and hence into the amniotic fluid (4). The size of LBs, similar to platelets, permits the use of a standard hematologic counter to quantify LB concentration in amniotic fluid samples. This technique quantitatively estimates surfactant production and thus can predict the degree of fetal lung maturation. Still, there are no clearly established protocols and cutoff values for LBC that predict RDS (4). The maturity thresholds for LB vary due to different factors, ie, centrifugation (leads to substantial loss of the LBs), sample contamination (meconium or platelets from the blood can be counted as LBs), and sample type (vaginal pool specimen containing mucus can artificially increase the LBC) (10,11). Depending on the protocols, the cutoff values of LBC that predict the absence of neonatal RDS can vary from 15 000 to even 80 000/µL (4,10,11). Also, the type of particle count analyzer used is critical in setting the cutoff values, so it has been proposed to establish analyzer-specific references for LBC (1). The aim of our investigation was to evaluate the LBC cutoff value using Cell-Dyn 1800 analyzer (Abbott Diagnostics, Abbott Park, IL, USA) and evaluate the efficiency in predicting different grades of neonatal RDS.

Introduction. Respiratory distress syndrome of the newborn caused by the fetal lung immaturity is a very serious clinical problem. Different tests of prenatal analysis of amniotic fluid, such as lamellar body count and Clements’ test, are available for predicting the fetal lung maturity. Material and methods. A prospective clinical study was conducted on amniotic fluid samples from 2005 to 2006. The amniotic fluid samples were obtained at the gestational age of 30 to 42 weeks and collected by vaginal amniotomy, amniotomy during Caesarean section and 72 hours before the delivery by amniocentesis. A haematology analyzer (Nikon-Kohden®) was used to determine the lamellar body counts. Clements’ test involved adding an equal volume of 96% ethanol to the multiple amniotic fluid volume (1:2, 1:4, 1:16, 1:32), followed by shaking and noting the presence of ring of bubbles. After the delivery, we compared the lamellar body count results and Clements’ test and the outcome of pregnancies, primarily the development of respiratory distress syndrome. The most specific lamellar body cutoffs for maturity and immaturity were determined according to receiver operating characteristic curves. Results and Discussion. Out of 232 amniotic fluid samples which were tested, 112 samples were collected after vaginal amniotomy, 88 during the Caesarean delivery and 32 samples by amniocentesis. The overall incidence of respiratory distress syndrome was 14.6%. Receiver operating characteristic curves were used to identify cutoff points for the test. We found that both tests are good screening tests for predicting the fetal lung maturity with the area under the curve of 0.782 in Clements’ test and 0.751 in the lamellar body count. Clements’ cutoff 2 with sensitivity of 67.6% and specificity of 72.2%, proved best in the prediction of the fetal lung maturity. The lamellar body count cutoff of 42x10³/μl had the sensitivity of 82.4% and specificity of 64.6% in predicting the fetal lung maturity. Conclusion. Although both tests are good in predicting the fetal lung maturity, the lamellar body count has more advantages, because it is not only more objective, but also inexpensive, easy and fast to do, requires a small sample volume and is universally available.

OBJECTIVES: To evaluate the performance of lamellar body count in tracheal aspirates from intubated preterm babies to predict respiratory distress syndrome. DESIGN: Case-control study. SETTING: Three neonatal intensive care units. PATIENTS: Seventy-two patients not older than 3 days were included in the study, 38 preterm infants with respiratory distress syndrome, 16 preterms without respiratory distress syndrome, and 18 term infants. All required mechanical ventilation. INTERVENTIONS: Lamellar body count was performed in an automated cell counter. Tracheal samples were diluted in dithiothreitol without centrifugation and kept frozen at -20°C until use. Samples were placed in a dithiothreitol-containing test tube at a ratio of one part tracheal aspirate to six parts dithiothreitol solution, vortexed for 10 secs, and aspirated by the cell counter. Lamellar body count was performed using the platelet channel. All results were multiplied by seven. The stable microbubble test was done for comparison. MEASUREMENTS: Lamellar body count and stable microbubble test. MAIN RESULTS: Lamellar body count was significantly lower in the respiratory distress syndrome group compared with the non respiratory distress syndrome preterm group and also with the term group. The median and interquartile range obtained for lamellar body count were 38,500/μL (14,000-112,000) for the respiratory distress syndrome group, 822,500/μL (442,000-962,500) for the non respiratory distress syndrome preterm group, and 633,000/μL (322,000-1,608,000) for the term group (p < .001). The sensitivity and specificity of lamellar body count and stable microbubble test for the diagnosis of respiratory distress syndrome were calculated, taking into consideration the respiratory distress syndrome and the non respiratory distress syndrome preterm groups. Considering a cutoff point of 200,000 lamellar bodies/μL, lamellar body count sensitivity was 92.1% (95% confidence interval 78.6-98.3) and lamellar body count specificity was 93.8% (95% confidence interval 69.8-99.8). The area under the curve was 0.94 (95% confidence interval 0.84-1.00). CONCLUSIONS: Lamellar body count and stable microbubble test can be rapidly and easily performed on tracheal aspirates and they seem to have very good performance for diagnosing respiratory distress syndrome in intubated patients.

Introduction. Respiratory distress syndrome (RDS) of the newborn infant caused by immaturity of fetal lung is a very serious clinical problem. Surfactant is stored in the form of lamellar bodies. They are secreted into alveolar space and passed into amniotic fluid where they can be found. The similarity of lamellar body size to platelet size permits the use of a standard automated hematologic cell counter to estimate the number of lamellar bodies in amniotic fluid. Material and Methods. We conducted a prospective clinical study from 2005 - 2006 on amniotic fluid samples. Amniotic fluid samples were collected near delivery by transvaginal amniotomy, amniotomy during Cesarean section and 72 hours before delivery by amniocentesis. A hematology analyzer (Nikon - Kohden?) was used to determine the lamellar body counts. After birth of newborns we compared their complete clinical examination results particularly emphasizing the prediction of the method of RDS by lamellar body count. Maximally specific lamellar body cutoffs for maturity and immaturity were determined using ROC curves. Results and Discussion. Of 232 amniotic fluid samples which were tested, 112 samples were collected by transvaginal amniotomy, 88 were taken during Cesarean delivery and 32 samples were collected by amniocentesis. The incidence of RDS was 14.6%. ROC curves were used to identify cut points for the test. We found that LBC is a good screening test for predicting fetal lung maturity with the area under the curve of 0.751. LBC cutoff of 42x10?/?l, with sensitivity of 82.4% and specificity of 64.6%, proved best for predicting fetal lung maturity. Conclusion. LBC is a good screening test for predicting fetal lung maturity. The advantages of LBC are speed, objectivity, low price, low sample volume required and universal availability.

Even though artificial surfactant is now available, respiratory distress syndrome still remains a serious problem in neonatology. Prenatal analysis of the amniotic fluid can provide data giving insight into the fetal lung maturity, which enables planning of the further outcome of high-risk pregnancies. Surfactant prevents atelectasis by forming a layer rich in phospholipids between the air and liquid phase in alveoli thus leading to increased surface tension in them, which is a precondition for a good lung function after birth. Lamellar bodies are a form of stored surfactant, and their count in the amniotic fluid can be determined simply by a standard hematology analyzer. The method of determining lamellar body count has found an important place in prenatal diagnostics and is recommended as an initial method of a ?cascade? procedure of testing fetal lung maturity. However, considering the importance of procedure of sample collection, storage and centrifugation, which can significantly affect the results obtained for the lung maturity, the amniotic fluid samples must be absolutely free of contamination with blood, meconium, mucus, bacteria and leucocytes.

Aims: The purpose of this study is to predict the occurrence of transient tachypnea of the newborn (TTN) using amniotic lamellar body count (LBC) and compare the LBCs in neonates with TTN with the LBCs in neonates with respiratory distress syndrome (RDS) and controls. Methods: Three hundred and eighty-one amniotic fluid samples were obtained at cesarean section from 27 to 40 weeks of gestation. Samples were analyzed immediately without centrifugation and the number of lamellar bodies was counted. Results: The LBC in amniotic fluid ranged from 1,000 to 577,000/μL. An LBC cut-off value of 48,500/μL resulted in 84.7% sensitivity, 76.2% specificity, and 98.1% negative predictive value for predicting TTN. The LBC in neonates with TTN was significantly lower than that in controls (50,000 vs. 122,000; P < 0.001) and significantly higher than that in neonates with RDS (50,000 vs. 21,000; P=0.042). Conclusions: We established a cut-off value of LBC for predicting the occurrence of TTN. The LBC in neonates with TTN was significantly lower than that in controls. Amniotic LBC can be a useful marker to predict if neonatal respiratory management is required.

Background The surfactant/albumin ratio is a popular fetal lung maturity (FLM) test that will be unavailable in the near future. We conducted surveys of obstetricians and clinical laboratorians to assess FLM testing trends from the perspectives of both disciplines and to identify how both communities might adapt to the loss of the surfactant/albumin ratio. Methods 2067 physicians were surveyed about their familiarity with and clinical utility of various FLM tests. 6137 laboratorians were surveyed about their FLM test menu and volumes. Results Twenty-five percent of physicians indicated a decrease in FLM test ordering and the frequency of FLM testing has decreased significantly (p = 0.011) since 1998. The surfactant/albumin ratio is the most frequently offered FLM test and was the test of choice for 62% of physicians. Without the surfactant/albumin ratio, 68% of physicians would order the lecithin/sphingomyelin ratio and 44% would order the lamellar body count (LBC) which were offered by 18 and 13% of laboratories, respectively. 16% of laboratories were planning to offer the LBC within 24 months. Conclusions FLM testing is decreasing. The loss of the surfactant/albumin ratio will increase the demand for the lecithin/sphingomyelin ratio and the LBC, yet few laboratories offer either test and most are not planning to offer the LBC.

Backgrounds. The lecithin/spingomyelin (L/S) ratio and lamellar body count (LBC) are two tests that can be used to estimate the probability of the occurrence of respiratory distress syndrome (RDS). Our objective was to compare the prognostic capacity of the L/S ratio and the LBC in the prediction of RDS from amniotic fluid that was obtained either transabdominally or vaginally. Methods. Consecutive women undergoing amniotic fluid sampling for determination of fetal lung maturity were included. In case the membranes were ruptured, amniotic fluid was obtained vaginally. Otherwise, amniotic fluid was obtained by transabdominal amniocentesis. In each specimen, an L/S ratio and a LBC were measured. The predictive capacity of specimens that were obtained vaginally and transabdominally were compared by calculating the area under the receiver-operating-characteristic curve (AUC) analysis. Results. In 260 patients amniotic fluid was collected transabominally, whereas in the other 67 patients there were ruptured membranes, and fluid was collected vaginally. RDS occurred in 25% of the patients without ruptured membranes, and in 34% of the patients with ruptured membranes. For the L/S ratio, the AUC was 0.56 (SE 0.09) for the vaginally collected specimens, and 0.93 (SE 0.02) in the specimens that were collected abdominally. For the LBC, the AUCs were 0.52 (SE 0.08) and 0.84 (SE 0.03), respectively. Conclusions. Fetal lung maturity tests that are performed in vaginally obtained specimens in patients with ruptured membranes are of no use in the prediction of RDS

To examine the lamellar body count (LBC) value in intra-amniotic infection cases and evaluate its association with the incidence of respiratory distress syndrome (RDS).Three hundred sixty-five amniotic fluid (AF) samples were obtained at caesarean section from 27 to 38 weeks of gestation. LBC and glucose concentrations in AF were measured with no centrifugation. We defined AF glucose concentrations0.8 mmol/L and positive C-reactive protein (CRP) of the neonates as intra-amniotic infection.An LBC cutoff value of 29,500/μL resulted in 94.0% sensitivity, 82.4% specificity, and 99.1% negative predictive value (NPV) for RDS. Neonates with glucose concentrations0.8 mmol/L in AF and positive CRP had no RDS and significantly higher LBC values than controls before 34 weeks of gestation (17.0 vs. 4.3, p0.05 and 25.5 vs. 5.0, p0.05, respectively), but there were no significant differences after 34 weeks of gestation.LBC is an accurate predictor of foetal lung maturity and our LBC cutoff value had a high NPV for predicting RDS. We showed that intra-amniotic infection was associated with significantly higher LBC values than the value in controls before 34 weeks of gestation, which correlated with a low incidence of RDS.

OBJECTIVES: The lecithin/sphingomyelin (L/S) ratio and the lamellar body count (LBC) can be used to predict respiratory distress syndrome (RDS). DESIGN: We performed a retrospective cohort study among consecutive women who underwent amniotic fluid sampling for the assessment of fetal lung maturity. Logistic regression was used to construct models for the prediction of RDS in three gestational age categories, with models based on clinical characteristics only, clinical characteristics and the LBC, and on clinical characteristics and L/S ratio. RESULTS: When amniotic fluid was collected

To evaluate the influence of glycemic control on fetal lung maturity in pregnancies affected by diabetes or mild hyperglycemia.Cross-sectional study.Level III maternity center.A total of 187 pregnant women were submitted to routine amniocentesis for the assessment of fetal lung maturity up to 72 hours before delivery.Fetal lung maturity thresholds were: Clements-positive at a dilution of 0.5; OD(650) (nm)or =0.15; and lamellar body count (LBC)or = 32,000/microl. The relation of test results with adequate (or =6.7 mmol/l) or poor (6.7 mmol/l) glycemic mean (GM) at term and at preterm was evaluated.Delay in fetal lung maturity when glycemic control was poor.Glycemic control was adequate in 146 (78.1%) women. Clements maturity rates were higher at term (91.9%) than at preterm (64.7%) when GMor = 6.7 mmol/l (p0.001), but not when control was inadequate. LBC median was higher at term (99.0; 62.0-154.0) than at preterm (66.5; 40.5-108.25) (p=0.009) when GMor = 6.7 mmol/l, while GM6.7 mmol/l did not lead to any difference between these rates at term or preterm. When glycemic control was adequate, OD(650) (nm) medians at term and at preterm were similar. However, when GM6.7 mmol/l, OD(650) (nm) median at term (0.29; 0.22-0.40) was higher than that observed at preterm (0.15; 0.12-0.18) (p0.001).Our results suggest that in term pregnancies routine amniocentesis for the assessment of fetal lung maturity should be abandoned. In preterm pregnancies, or when glycemic control is inadequate it is recommended.