Lamellar body count: Marker for foetal lung maturation promoted by intra-amniotic infection and/or inflammation.

OBJECTIVE: There is evidence indicating that the risk of respiratory distress syndrome is reduced in preterm neonates exposed to intra-amniotic infection and/or inflammation. We hypothesised that foetal lung maturation promoted by intra-amniotic infection and/or inflammation results in elevated lamellar body count (LBC) in amniotic fluid (AF). This study aimed to determine the relationship between LBC in AF and intra-amniotic infection and/or inflammation in patients with threatened preterm birth. STUDY DESIGN: This was a retrospective cohort study of patients with threatened preterm birth. A total of 104 consecutive pregnant women underwent amniocentesis in the early preterm period [gestational age < 34 weeks] to evaluate intra-amniotic infection and/or inflammation and foetal lung maturity. Intra-amniotic infection was confirmed by positive AF culture results for aerobic/anaerobic bacteria, fungi, and genital mycoplasma. Intra-amniotic inflammation was defined as a positive AF matrix metalloproteinase-8 rapid test. Outcomes of the study population were compared according to LBC in AF using a cut-off of 15,000/mm3. RESULTS: The rates of elevated LBC and intra-amniotic infection and/or inflammation were 23% (24/104) and 52% (54/104), respectively. The median LBC was significantly higher in patients with intra-amniotic infection and/or inflammation than in those without [median LBC, 9,000/mm3 (interquartile range, IQR: 3,000-39,000) vs. 3,000/mm3 (IQR: 2,750-5,000), p < 0.001]. Intra-amniotic infection and/or inflammation was observed in 96% (23/24) of patients with elevated LBC and 39% (31/80) of patients without elevated LBC (p < 0.001). On multivariable analysis, the presence of intra-amniotic infection and/or inflammation was significantly associated with elevated LBC with an odds ratio (OR) of 66.0 [95% confidence interval (CI) 6.6-664.4, p < 0.001], even after accounting for gestational age at amniocentesis being a significantly related factor for predicting elevated LBC with an OR of 1.5 (95% CI 1.1-2.0, p = 0.004). CONCLUSION: LBC elevation was independently associated with the presence of intra-amniotic infection and/or inflammation in women with early threatened preterm birth (gestational age < 34 weeks). This finding may support the view that an intra-amniotic inflammatory response promotes foetal lung maturation that can be detected by elevated LBC in AF.

Diagnostic accuracy of lamellar body count as a predictor of fetal lung maturity: A systematic review and meta-analysis.

OBJECTIVE: This study aimed to synthesize evidence from published studies about the diagnostic accuracy of lamellar body count (LBC) as a predictor of fetal lung maturity. STUDY DESIGN: We searched Medline (via PubMed), EBSCO, Web of Science, Scopus and the Cochrane Library for relevant published studies assessing the accuracy of LBC as a predictor of fetal lung maturity. Studies were classified according to the counting essays, centrifugation protocols, and the reported optimum cut off values. Data of the true positive, true negative, false positive, and false negative were extracted and analyzed to calculate the overall sensitivity and specificity of the LBC. RESULTS: Thirty-one studies were included in the final analysis. Fourteen studies reported data for centrifuged amniotic fluid (AF) samples, 13 studies reported data for uncentrifuged samples, and four studies did not have enough information about whether centrifugation was done. LBC showed an area under the curve >80% in diagnosing lung immaturity with variable cut off values. Pooled analysis showed that LBC a 100% specificity to exclude respiratory distress syndrome (RDS) at a cut off value of 15,000 and 100% sensitivity to diagnose RDS at a cut off value of 55,000. CONCLUSION: Cases with LBC < 15,000 are considered to have lung immaturity while cases with LBC > 45,000 in centrifuged AF samples or >55,000 in uncentrifuged AF samples are likely to have mature lungs. Cases with LBC ranging between these maturity and immaturity limits should be considered for further evaluation by other lung maturity tests.

Maternal plasma LPCAT 1 mRNA correlates with lamellar body count.

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.

Relationship between Ultrasonic Marker of Fetal Lung Maturity and Lamellar Body Count.

BACKGROUND: The aim of this study was prediction the fetal lung maturity by ultrasonic markers and comparison by lamellar body count and fetal outcome. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Predicting respiratory distress syndrome using gestational age and lamellar body count.

OBJECTIVES: To design a predictive model for assessing the risk of developing respiratory distress syndrome (RDS) using gestational age (GA) and lamellar body counts (LBC). DESIGN AND METHODS: LBCs and patient outcome data was obtained from five medical centers. A total of 223 patients were included in this study; 19 gave birth to infants that developed RDS, 204 gave birth to infants that were unaffected. The absolute risk and odds ratios of an infant developing RDS as a function of GA and LBC were calculated. Logistic analysis was used to model the odds of RDS as a function of GA and LBC. RESULTS: The odds of RDS decreased for each increasing week of GA and decreased with increase in the LBC. GA-specific LBC cutoffs are provided for sensitivities between 84 and 100%. The bias adjusted area under the ROC curve for the classification of RDS, based on GA and LBC, was 0.906 using the logistic model and 0.746 using a single cutoff of LBC (50,000/µL) to classify immaturity. CONCLUSIONS: GA-specific risk assessment and GA-specific cutoffs provide increased sensitivity and specificity in the evaluation of fetal lung maturity.

Lecithin/sphingomyelin ratio and lamellar body count for fetal lung maturity: a meta-analysis.

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 24h per day.

The Efficacy of Lamellar Body Counts for Prediction of Perinatal Outcome / 대한산부인과학회잡지

OBJECTIVE: This study is aimed to evaluate whether lamellar body count (LBC) in amniotic fluid could be used as a predictor of neonatal morbidity as well as respiratory distress syndrome (RDS) and to determine the value of lamellar body count that maximizes sensitivity and specificity. METHODS: We conducted a prospective clinical outcome study. Amniotic fluid was obtained from 39 pregnant women at various gestational ages (29 to 36 weeks) from March 1, 2002 to February 28, 2003. They delivered within 72 hours of amniocentesis, excluding 6 cases of contaminated amniotic fluid. A LBC was performed on each specimen. The frequencies of RDS, minor and major morbidity of newborn in different LBC cutoff value were analyzed. Statistic analysis was done by Chi-square test. RESULTS: LBCs increased with gestation (r=0.533, p<0.05). The LBC cutoff value that best agreed with RDS (sensitivity 36.4%, specificity 93.8%), minor morbidity (sensitivity 100.0%, specificity 50.0%) and major morbidity (sensitivity 45.5%, specificity 81.3%) was 30,000/ l. CONCLUSION: These results indicate that LBC might be useful as a predictor of neonatal morbidity as well as respiratory distress syndrome.

The clinical efficacy and cost-effectiveness of Lamellar body count in fetal lung maturation test / 대한산부인과학회잡지

OBJECTIVE: To evaluate the availability and efficacy of the Lamellar body count as a predictor of fetal lung maturity METHODS: Amniocentesis was performed for evaluation of fetal lung maturity status within 72 hours of delivery in 32 patients. A Lamellar body count in clean amniotic fluid (AF) was analyzed right after amniocentesis. In case of contaminated AF with meconium or blood, samples was centrifuged for 3 minutes and divided into three. The average of three samples was analyzed successively from Coulter counter. RESULTS: The incidence of RDS showed significant relation with gestational age, 1-minute and 5-minute Apgar Score. Using a value greater than 30,000/ l to indicate pulmonary maturity, the Lamellar body count predicted all lung-maturated cases with no false-negative results (100% negative predictive value). All 4 cases of RDS demonstrated Lamellar body count less than 30,000/microl. By using a lower cutoff of 10,000/microl to predict pulmonary immaturity. Positive predictive value was 100% in RDS patients. CONCLUSION: In high risk pregnancy, fetal lung maturity test from amniotic fluid lamellar body count is a rapid, simple and reliable method in making a decision of delivery-time. And also it has universal availability with cost-effectiveness when we consider the reality of korean medical situation

The Clinical Efficacy of Lamellar Body Count to Predict Fetal Lung Maturity / 대한산부인과학회잡지

From July 1994 through August 1995, 31 patients who delivered before 37 weeks gestation at the Ajou University Hospital were tested for lamellar body count in the amniotic fluid. The obtained results are summarized as follows; 1. Lamellar body count was associated with 1 minute Apgar score(p=0.02). 2. There was no sexual, gestational and birth weight differences in the incidence of respiratory distress syndrome. 3. Lamellar body count showed that the positive predictive value for respiratory distress syndrome was 90.0 %, the negative predictive value was 95.2 %, and the sensitivity was 90.0 %, and the specificity was 95.2 %, therefore it may be regarded as more accurate than other previously employed methods. This study suggests that the lamellar body count reflects fetal lung maturity sufficiently to assure that the neonate will not develop respiratory distress syndrome, and can be used as a quick screening test or one in series of tests for thorough assessment of fetal lung maturity.