Prediction Of Fetal Lung Maturity Research Articles

Lamellar bodies as a predictor of fetal lung maturity

Introduction: Respiratory disorders remain an important newborn complication. Currently, there have been alarming information about the impact of repeated courses (even one “resque” course) of RDS prophylaxis on the quality of health in childhood and adulthood. Therefore, the search for available tests to determine the fetal lungs maturity in women at high risk of PTB is an important practical problem. Lamellar bodies (LBCs) produced by type II pneumocytes and appearing in the amniotic fluid in 28–32 weeks may serve as a possible such potential marker.

Lamellar Body Count With Cell Dyn Emerald And Cell Dyn Ruby Methods On Preterm Birth

Background: Lamellar bodies are produced by pneumocyte type II cells in the lung alveoli. Lamellar bodies are present in amniotic fluid in increasing quantities as gestation advances, 1 – 5 µm in size, similar in size to small platelets and can be counted on most electronic cell counters in hematology analyzer. Lamellar body count is useful for prediction of fetal lung maturity and neonatal respiratory distress syndrome. The current gold standard for determination of fetal lung maturity is the evaluation of phospholipids in amniotic fluid samples by thin-layer chromatography, but it is time-consuming and not continuously available at most institutions. In this study we compare Cell Dyn Emerald and Cell Dyn Ruby method, which is expected to be a review for lamellar body count method. Purpose: The aim of this study was to analyze lamellar body count with Cell Dyn Emerald and Cell Dyn Ruby method on preterm birth. Methods : This was a cross sectional study. Thirty three samples study were inpatient’s amniotic fluid with premature rupture of membranes in Obstetry and Gynecology ward emergency room Dr. Soetomo Hospital Surabaya. Lamellar body count was counted with Cell Dyn emerald and Cell Dyn Ruby method. The statistical differences were assessed using the ANOVA test . Results : The results showed significant differences (t=49,04), lamellar body count with Cell Dyn Ruby method was much lower than Cell Dyn Emerald method. The lowest result with Cell Dyn Ruby method was 3.38 x 103/µL and 17 x 103/ µL with Cell Dyn Emerald method. The highest results with Cell Dyn Ruby method was 98,2 x 103/ µL and 221 x 103/ µL with Cell Dyn Emerald method. Conclusion : Lamellar body count with impedance method (Cell Dyn Emerald) is significantly higher than optic method (Cell Dyn Ruby).

671: The accuracy of lamellar body count for prediction of fetal lung maturity: a systematic review and meta-analysis

671: The accuracy of lamellar body count for prediction of fetal lung maturity: a systematic review and meta-analysis

Amniotic Fluid Lamellar Bodies Count as a Predictor of Fetal Lung Maturity in High Risk Pregnancy

Amniotic Fluid Lamellar Bodies Count as a Predictor of Fetal Lung Maturity in High Risk Pregnancy

Feasibility and Reproducibility of Fetal Lung Texture Analysis by Automatic Quantitative Ultrasound Analysis and Correlation with Gestational Age

Objective: To evaluate the feasibility and reproducibility of fetal lung texture analysis using a novel automatic quantitative ultrasound analysis and to assess its correlation with gestational age. Methods: Prospective cross-sectional observational study. To evaluate texture features, 957 left and right lung images in a 2D four-cardiac-chamber view plane were previously delineated from fetuses between 20 and 41 weeks of gestation. Quantification of lung texture was performed by the Automatic Quantitative Ultrasound Analysis (AQUA) software to extract image features. A standard learning approach composed of feature transformation and a regression model was used to evaluate the association between texture features and gestational age. Results: The association between weeks of gestation and fetal lung texture quantified by the AQUA software presented a Pearson correlation of 0.97. The association was not influenced by delineation parameters such as region of interest (ROI) localization, ROI size, right/left lung selected or sonographic parameters such as ultrasound equipment or transducer used. Conclusions: Fetal lung texture analysis measured by the AQUA software demonstrated a strong correlation with gestational age. This supports further research to explore the use of this technology to the noninvasive prediction of fetal lung maturity.

151: Assessing vaginal amniotic fluid (AF) for lamellar bodies (LB) as a predictor of fetal lung maturity after preterm rupture of membranes (PPROM)

PPROM is a risk factor for cord accident and chorioamnionitis. It is accepted that delivery is justified beyond 34w of gestation. Before 34w, amniocentesis is offered for assessing fetal lung maturity. Aniocentesis is an invasive procedure which harbors a risk of iatrogenic infection and may be difficult in cases of oligohydramnios. The purpose of this study was to validate an alternative non-invasive measurement of LB drawn from a vaginal pool for predicting fetal lung maturity and to set a cutoff for LB concentration above which fetal lung maturity is likely.

OC077: Acceleration/ejection time ratio in the fetal pulmonary artery as a predictor of fetal lung maturity

OC077: Acceleration/ejection time ratio in the fetal pulmonary artery as a predictor of fetal lung maturity

Contagem de corpos lamelares versus teste de Clements na avaliação da maturidade pulmonar fetal em gestantes diabéticas

OBJETIVOS: analisar a contagem dos corpos lamelares em comparação com o teste de Clements na avaliação da maturidade pulmonar fetal em gestantes diabéticas. MÉTODOS: estudo prospectivo envolvendo 62 gestantes submetidas a amniocentese entre a 26ª e a 39ª semana. O líquido amniótico foi imediatamente submetido ao teste de Clements e à contagem de corpos lamelares. Os partos ocorreram até três dias após a amniocentese. A ocorrência de síndrome de angústia respiratória, indicativa de imaturidade pulmonar, foi confrontada com os resultados de imaturidade da amniocentese (ausência de anel completo no 3º tubo e menos de 50.000 corpos lamelares). O teste do chi2 foi utilizado para comparar o desempenho dos dois métodos e p<0,05 foi considerado significante. RESULTADOS: sete neonatos apresentaram síndrome de angustia respiratória (11,3%). A contagem de corpos lamelares e o teste de Clements tiveram desempenhos semelhantes quanto à sensibilidade (100 vs 71,4%, respectivamente) e valor preditivo negativo (100 vs 93,5%). A contagem de corpos lamelares teve melhor especificidade (87,3% vs 52,7; p<0,001), valor preditivo positivo (50 vs 16,1%; p=0,017) e acurácia (88,7% versus 54,8%; p<0,001) que o teste de Clements. CONCLUSÕES: a contagem de corpos lamelares revelou ser método simples e preciso na avaliação da maturidade pulmonar fetal. Comparado ao teste de Clements, tem a vantagem de não necessitar de manipulações e reagentes e de ter melhor desempenho quanto à especificidade, valor preditivo positivo e acurácia. Assim como o teste de Clements, a contagem de corpos lamelares tem alto valor preditivo negativo, assegurando que diante de um resultado maduro (50.000 ou mais), não ocorrerá síndrome de angustia respiratória.

Role of lamellar body count for the prediction of neonatal respiratory distress syndrome in non-diabetic pregnant women.

Lamellar body count is a new and fast technique to establish the presence of fetal lung maturity. We have assessed the predictive ability of lamellar body count for neonatal respiratory distress syndrome (RDS) in a non-diabetic population. We accessed a cohort of amniocenteses in non-diabetic women from 1998 to 2002 (n=102). Neonatal RDS was defined as need for surfactant, intubation, or continuous positive airway pressure (CPAP) in the setting of chest X-ray findings consistent with RDS. The predictive ability of lamellar body count was compared with those of lecithin/sphingomyelin (L/S) ratio and presence of phosphatidylglycerol (PG) using logistic regression analysis. The optimal threshold value of lamellar body count for prediction of neonatal RDS was established with receiver operating characteristic (ROC) curve analysis. Lamellar body count ROC curve analysis identified a lamellar body count >37,000 microl(-1) as optimal diagnostic threshold for diagnosis of lung maturity, having a negative predictive value of 98%. Lamellar body count and PG, but not L/S ratio, added significantly to the prediction of RDS. Lamellar body count is a reliable predictor of fetal lung maturity in non-diabetic women and it can replace the L/S ratio.

Lamellar body count in amniotic fluid: a comparative study of four different hematology analyzers.

The accurate antenatal prediction of fetal lung maturity (FLM) based on results from amniotic fluid samples is of utmost importance in the prevention of neonatal respiratory distress syndrome and its complications. The current “gold standard” for the determination of FLM is the evaluation of phospholipids (i.e., measurement of lecithin/sphingomyelin ratio and quantification of phosphatidylglycerol) in amniotic fluid samples by thin-layer chromatography. These tests are, however, time-consuming and not continuously available at most institutions. Lamellar bodies are lamellated phospholipids that represent a storage form of surfactant (1). Because lamellar body diameter (range, 1–5 μm) is similar to that of small platelets, lamellar body counts (LBCs) can be obtained rapidly with use of the platelet channel of a hematology analyzer (2). Recently, a consensus LBC protocol was published, and a FLM cutoff of 50 000/μL was suggested without discussion regarding the hematology analyzer used (3). The majority of published reports to date have used a Coulter brand of hematology analyzer to establish clinical decision limits (2)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). The published experience with other hematology analyzers, such as the Sysmex NE-1500 (14), for obtaining LBCs is limited. One study used LBCs from three different analyzers (two from Coulter, one from Sysmex) to assess FLM without providing any evidence that the instrumentation was not a source of imprecision (9). Our objective was therefore to compare LBC concordance from the following four hematology analyzers: Coulter Gen-S (Beckman Coulter), Sysmex XE-2100 (Sysmex), Cell-dyn 3500 (Abbott Laboratories), and ADVIA 120 (Bayer Corporation). Leftover amniotic fluid samples sent to the Barnes-Jewish …

The use of lamellar body counts to predict fetal lung maturity in pregnancies complicated by diabetes mellitus

Objective: The purpose of this study was (1) to correlate amniotic fluid lamellar body counts with the lecithin/sphingomyelin ratio and the presence of phosphatidylglycerol in pregnancies that were complicated by maternal diabetes mellitus and (2) to determine a lamellar body count value that maximizes sensitivity and specificity in the prediction of fetal lung maturity. Study Design: We reviewed our prospectively collected perinatal database from November 1992 through October 1999 to identify pregnancies that were complicated by diabetes mellitus for which fetal lung maturity studies had been performed within 72 hours of delivery. Lamellar body counts were correlated with lecithin-sphingomyelin ratio and phosphatidylglycerol values. The sensitivities and specificities of various lamellar body count cutoff values were calculated with the lecithin/sphingomyelin ratio and phosphatidylglycerol values as indicators of fetal lung maturity. Receiver operating curves were used to determine the lamellar body count that indicated fetal lung maturity. Our neonatal database was reviewed for this same time period to obtain all cases of respiratory distress syndrome. The maternal data were compared with the neonatal data to determine whether distress syndrome had developed in an infant who had undergone fetal lung maturity testing respiratory. Results: Lamellar body counts were correlated with lecithin/sphingomyelin ratio (r = 0.51, P <.001) and phosphatidylglycerol values (r = 0.57, P <.001) in 90 diabetic pregnant patients. A lamellar body count of 37,000/μL was found to have a sensitivity of 80% and a specificity of 100% in the prediction of fetal lung maturity by standardized methods of phospholipid analysis. There were no cases of neonatal respiratory distress syndrome in this study population. Conclusion: The lamellar body count is a valid, rapid screening test for the determination of biochemical fetal lung maturity in pregnancies that are complicated by diabetes mellitus. A lamellar body count of ≥37,000/μL correlated with the lecithin/sphingomyelin ratio and phosphatidylglycerol values in the pregnancies of diabetic patients. Use of lamellar body counts in pregnancies that are complicated by diabetes mellitus could decrease the need for time-consuming and more costly phospholipid profiles. A full phospholipid profile is recommended for amniotic fluid specimens with lamellar body count values of <37,000/μL. (Am J Obstet Gynecol 2002;187:908-12.)

580 The use of lamellar body counts as a predictor of fetal lung maturity in pregnancies complicated by diabetes

580 The use of lamellar body counts as a predictor of fetal lung maturity in pregnancies complicated by diabetes

Comparison of infrared spectroscopic and fluorescence depolarization assays for fetal lung maturity

Objective: Infrared spectroscopic analysis of amniotic fluid was recently shown to be a potential useful method for the determination of fetal lung maturity. Those studies used thin-layer chromatography as a reference method for the calibration of the infrared-based technique. However, thin-layer chromatography is compromised by large intra-assay and interlaboratory coefficients of variation. Therefore in this study we have used a reference method that is based on fluorescence depolarization, the TDx FLM II assay, to verify the sensitivity and precision of infrared spectroscopy for assessment of fetal lung maturity status. Study Design: Samples of amniotic fluid were obtained by amniocentesis from 101 patients between the 24th and 40th weeks of pregnancy. Small volumes (35 μL) of amniotic fluid specimens were dried, and the infrared spectra were measured with a commercial infrared spectrometer. The fetal lung surfactant/albumin ratio was determined separately for each specimen with the TDx FLM II assay. The proposed infrared method was then calibrated and tested with a partial least-squares regression analysis to quantitatively correlate the infrared spectra with the surfactant/albumin ratios provided by the TDx FLM II assays. Results: A total of 144 training spectra were used to build the partial least-squares calibration model. The correlation coefficient for the training set was excellent (r = 0.92), with an SE between infrared-predicted and reference surfactant/albumin ratios of 17 mg/g. The model was then validated on a set of 69 test spectra and yielded an SE of 14 mg/g (r = 0.86). The final partial least-squares model included the 900- to 1500-cm–1 and 2800- to 3200-cm–1 spectral ranges and 6 partial least-squares factors. Conclusion: Because the infrared-based fetal lung maturity measurements correlated well with assays from both of the current standard clinical techniques (thin-layer chromatography and fluorescence depolarization) and the procedure is less labor and training intensive, we concluded that infrared spectroscopy has the potential to emerge as the method of choice for prediction of fetal lung maturity from amniotic fluid analysis. (Am J Obstet Gynecol 2000;183:181-7.)

Comparison of infrared spectroscopic and fluorescence depolarization assays for fetal lung maturity

Objective: Infrared spectroscopic analysis of amniotic fluid was recently shown to be a potential useful method for the determination of fetal lung maturity. Those studies used thin-layer chromatography as a reference method for the calibration of the infrared-based technique. However, thin-layer chromatography is compromised by large intra-assay and interlaboratory coefficients of variation. Therefore in this study we have used a reference method that is based on fluorescence depolarization, the TDx FLM II assay, to verify the sensitivity and precision of infrared spectroscopy for assessment of fetal lung maturity status. Study Design: Samples of amniotic fluid were obtained by amniocentesis from 101 patients between the 24th and 40th weeks of pregnancy. Small volumes (35 μL) of amniotic fluid specimens were dried, and the infrared spectra were measured with a commercial infrared spectrometer. The fetal lung surfactant/albumin ratio was determined separately for each specimen with the TDx FLM II assay. The proposed infrared method was then calibrated and tested with a partial least-squares regression analysis to quantitatively correlate the infrared spectra with the surfactant/albumin ratios provided by the TDx FLM II assays. Results: A total of 144 training spectra were used to build the partial least-squares calibration model. The correlation coefficient for the training set was excellent (r = 0.92), with an SE between infrared-predicted and reference surfactant/albumin ratios of 17 mg/g. The model was then validated on a set of 69 test spectra and yielded an SE of 14 mg/g (r = 0.86). The final partial least-squares model included the 900- to 1500-cm–1 and 2800- to 3200-cm–1 spectral ranges and 6 partial least-squares factors. Conclusion: Because the infrared-based fetal lung maturity measurements correlated well with assays from both of the current standard clinical techniques (thin-layer chromatography and fluorescence depolarization) and the procedure is less labor and training intensive, we concluded that infrared spectroscopy has the potential to emerge as the method of choice for prediction of fetal lung maturity from amniotic fluid analysis. (Am J Obstet Gynecol 2000;183:181-7.)

Interobserver reliability of the click test: a rapid bedside test to determine surfactant function.

To determine the interobserver reliability of the click test, a rapid bedside test of surfactant function. One hundred samples (48 amniotic fluid, 28 gastric aspirates, 24 tracheal aspirates) were obtained from pregnant women, term and preterm infants managed at two perinatal centres. Gestational ages of the pregnancies or infants at time of sampling ranged from 24 to 40 weeks (mean +/- s.d.: 31+/-5). The click test was performed independently by two observers, with differing levels of experience, and blinded to each other's results. Interobserver reliability was determined for samples classified as negative (no clicking bubbles), equivocal (a few clicking bubbles seen after 2 min of looking), and positive (clicking bubbles seen easily on first look). As negative and equivocal test results suggest surfactant dysfunction, these results were also combined to provide a dichotomised result. For samples classified as negative, equivocal and positive the interobserver agreement was 0.83, with agreement beyond chance shown by a quadratic weighted Kappa of 0.74 (95% CI = 0.62-0.86). When negative and equivocal results were combined, the simple Kappa was 0.73 (95% CI = 0.59-0.87). The click test has a high level of interobserver reliability. It is rapid, simple, accurate and able to be taught to medical and nursing staff with appropriate training. It has many potential applications including the prediction of fetal lung maturity in women with premature rupture of membranes, and in term and preterm infants who require the bedside testing of surfactant function.

Clinical Microscopy: Coulter STKSvsAbbott Cell-Dyn 3500 for Counting Lamellar Bodies in Amniotic Fluid

Lamellar body counts in human amniotic fluid assist in the prediction of fetal lung maturity and can be performed rapidly and inexpensively by using the platelet channel of a hematology analyzer. We compared two analyzers for enumerating lamellar bodies. We tested 100 fresh amniotic fluid samples on both instruments. The lamellar body counts ranged from 3 to 364 × 10 3 /μL (3−364 × 10 9 /L) on one analyzer and from 3 to 195 × 10 3 /μL (3−195 × 10 9 /L) on the other. Statistical analysis showed excellent correlation (r = 0.99) yielding a regression equation of y = 3.91 + .467x. This analysis demonstrates that institutions will be faced with the challenge of establishing and incorporating instrumentspecific lamellar body reporting protocols and reference ranges that include the specific analyzer and method used.

Prediction of fetal lung maturity from near-infrared spectra of amniotic fluid

Objective: The aim of this study was to attempt to correlate the quantitative data obtained from the near-infrared (near-IR) spectra of amniotic fluid with the lecithin/sphingomyelin ( L S ) ratio determined from thin layer chromatographic analysis on the same samples, in order to establish the feasibility of near-IR spectroscopy as an alternate method for the prediction of fetal lung development. Methods: Samples of amniotic fluid were obtained by amniocentesis from 52 patients between the 26th and 41st week of pregnancy. About 350 μl of amniotic fluid was required to record the near-IR spectrum over the entire spectral range between 400 and 2500 nm using a commercial spectrometer. The L S ratio was determined independently by thin layer chromatography (TLC) for each sample. For correlating the infrared spectra with the TLC-based L S ratios, a partial least squares analysis was used. Results: The L S ratios predicted from the near-IR spectra of amniotic fluid were highly correlated and in excellent agreement with those determined by TLC ( r = 0.91). Conclusion: Near-IR spectroscopy has the potential to become an alternate method to TLC for prediction of fetal pulmonary maturity.

Prediction of Fetal Lung Maturity in Infants of Diabetic Mothers Using the FLM S/A and Disaturated Phosphatidylcholine Tests

The authors evaluated the performance of the amniotic fluid surfactant to albumin ratio (FLM S/A), and disaturated phosphatidylcholine (DSPC) tests in assessing fetal lung maturity in infants of mothers with insulin-dependent diabetes mellitus antedating pregnancy. The distribution of the study population (n = 180) by class of diabetes was class B (27%); class C (28%); class D (29%); class F, FR and T (8%); and class R patients (8%). The diagnosis of respiratory distress syndrome (RDS) was the standard for evaluating the performance of FLM S/A and DSPC. The mean estimated gestational age was 37.4 weeks. Three infants (1.7%) were diagnosed with RDS. All three were delivered before 36 weeks. FLM S/A at the cut-off for "maturity" of > or = 70 mg/g, had a sensitivity of 66.6%, specificity of 94.9%, positive predictive value (PPV) of 18.2%, and negative predictive value (NPV) of 99.4%. DSPC at the cut-off for "maturity" of 1,000 micrograms/dL, had identical sensitivity and NPV, but lower specificity (89.2%) and PPV (9.5%) than FLM S/A. Both tests mispredicted maturity in the same case of RDS. The false "mature" rate of FLM S/A was 0.6% (95% confidence interval 0.0%-3.2%). The FLM S/A result of > or = 70 mg/g, obtained at or near-term, is a reliable predictor of the absence of RDS in infants of mothers with diabetes mellitus antedating pregnancy.

Amniotic fluid lamellar body count: a rapid and reliable fetal lung maturity test

To evaluate the lamellar body count as a predictor of fetal lung maturity. We conducted a prospective clinical outcome study. Amniocentesis was performed for evaluation of fetal lung maturity status within 72 hours of delivery in 130 patients. A lamellar body count was performed on each specimen, and a lecithin-sphingomyelin ratio and lung phospholipid profile were performed when possible (insufficient sample or contamination in eight cases). Each infant was evaluated for evidence of respiratory distress syndrome (RDS). A lamellar body count exceeding 30,000/microL predicted pulmonary maturity correctly in all cases (negative predictive value 1.00). All 16 cases of RDS had counts of 30,000/microL or less. If the lamellar body count was less than 10,000/microL, the positive predictive value for RDS was 67%, and the likelihood of a mature result from chromatographic phospholipid analysis was low (one of 14, 7%). Values between 10,000-30,000/microL indicated intermediate risk (four of 39, 10%) for developing RDS. Phospholipid analysis indicated fetal lung maturity in 35 of 39 (90%) cases with lamellar body counts in the intermediate risk range. The lamellar body count compares favorably with traditional phospholipid testing in the prediction of fetal lung maturity. Phospholipid analysis is not needed with lamellar body counts greater than 30,000/microL or less than 10,000/microL, but may be of benefit for values in the intermediate risk range. Advantages of this test include speed, objectivity, small sample volume required, and universal availability of instrumentation.

Enzyme-linked immunosorbent assay for human pulmonary surfactant protein D

We developed a simple and sensitive enzyme-linked immunosorbent assay (ELISA) for human pulmonary surfactant protein D (SP-D). Human SP-D was purified from bronchoalveolar lavage fluids of patients with pulmonary alveolar proteinosis. Nine monoclonal antibodies (MAbs) were established from BALB/c mice immunized of patients with pulmonary alveolar proteinosis or in amniotic fluids from healthy normal pregnancies. The ELISA is based on a sandwich method using two MAbs, 6B2 and 7C6. Cross-reactivity to human SP-A or rat SP-D was evaluated as below 0.6%. The recovery of different concentrations of SP-D ranged from 94.4% to 111.2%, and serial dilutions of amniotic fluids showed good linearity. SP-D concentrations in 21 amniotic fluids from normal pregnancies were measured by the ELISA. The mean concentrations in amniotic fluids pregnancies in the third trimester was significantly higher than that from earlier stages of gestation ( p < 0.001), indicating that this ELISA may be applicable for prediction of fetal lung maturity.