Ultrasonographic evaluation of fetal lung histogram versus lamellar body count in the prediction of fetal lung maturity (original) (raw)
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A New Method for Assessment of Fetal Lung Maturity
BJOG: An International Journal of Obstetrics and Gynaecology, 1976
A new method for evaluation of fetal lung maturity in utero is described. The method is based on the fluorescence polarization (P) of the lipids in the amniotic fluid after labelling with a special dye. Tests performed with 49 amniotic fluid samples drawn from 33 pregnancies clearly demonstrated a decrease in P during gestation which correlated with the increase in the lecithin/sphingomyelin ratio (L/S) in the fluid. During gestation the P value at 24 "C decreased steadily from about 0.4 to 0.2 and the value of P (24 "C)= 0.310 has been tentatively chosen as the threshold above which respiratory distress syndrome may develop. The described method, which requires a specially designed instrument, offers a series of important advantages over the presently available methods. It is simple, rapid, highly accurate and reproducible, and independent of amniotic fluid volume. The P value reflects the microviscosity in the whole lipid assembly of amniotic fluid and is not confined specifically to lecithin.
Assessment of the Diagnostic Accuracy of the TDx-FLM II to Predict Fetal Lung Maturity
Background: Because respiratory distress syndrome (RDS) affects 1% of live births, accurate and rapid assessment of markers of fetal lung maturity is critical to clinicians in deciding whether to deliver a preterm infant. Our objective was to determine the optimal diagnostic cutoff value for the TDx-FLM II assay (Abbott Laboratories) for predicting clinically significant RDS. Methods: Amniotic fluid TDx-FLM II data were collected retrospectively over 4 years. Women were included in the study if they had delivered within 72 h of TDx-FLM II testing and both the mother and infant charts could be reviewed. Women who had been treated with steroids and delivered unaffected infants were excluded from the analysis. The diagnosis of RDS was defined as infants who either were treated with surfactant and/or were placed on a ventilator and/or required continuous positive airway pressure for >1 day. Results: A total of 185 women met all entry criteria (15 RDS, 170 non-RDS). A cutoff value for a mature result of >45 mg/g gave a sensitivity of 100% (95% confidence interval, 82-100%) and a specificity of 90% (95% confidence interval, 78 -89%). Conclusions: The TDx-FLM II appears to predict clinically significant RDS when a cutoff of >45 mg/g is used for mature results. Further studies will be required to confirm these findings.
Fetal Lung Maturity Assessment With MRI Fetal Lung-to-Liver Signal-Intensity Ratio
American Journal of Roentgenology, 2013
E arly delivery because of fetal and maternal health concerns is steadily increasing in obstetric practice. According to the National Vital Statistics Report for 2006, 4.3 million births occurred in that year [1]. The rate of preterm births (before 37 weeks' gestation) increased to more than half a million, or 12.8% of all births. This was mostly due to a 25% increase in births at 34-36 weeks of gestation [1, 2]. According to data published by the Quint-Boenker Preemie Survival Foundation [3], infant survival is significantly dependent on gestational age at birth. For example, for infants born at 32-33 weeks, the survival rate is 98%, compared with those born at 25 weeks, who have a 50% survival rate. Sufficient fetal lung growth and maturation are key components in postnatal surviv
A Simple Method of Assessing Fetal Lung Maturity by Lamellar Body Concentration in Amniotic Fluid
Journal of South Asian Federation of Obstetrics and Gynaecology, 2018
Objective: To find out whether amniotic fluid lamellar body concentrations (LBC) can predict neonatal respiratory distress syndrome (RDS) Materials and methods: Amniotic fluid was obtained at the time of cesarean section was sent to the laboratory for lamellar body concentrations in amniotic fluid. The lamellar body concentrations were analyzed and correlated with the incidence of RDS. Results: The incidence of RDS at different gestational age with an LBC cut off of 41,500 was studied. Among 220 patients studied, Respiratory distress was seen in 53 (24.09%) of patients. There is a significant correlation between decreasing lamellar body count in preterms and incidence of RDS. LBC count has a sensitivity of 92.7 %, the specificity of 90 %, a positive-predictive value of 73% and a negative-predictive value of 98% in predicting respiratory distress syndrome. Conclusion: LBC count in the current study is a cheap, easy and reliable method of assessing fetal lung maturity.
European Journal of Obstetrics & Gynecology and Reproductive Biology: X, 2019
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.
Values and validity of fetal parameters by ultrasound and Doppler as markers of fetal lung maturity
Egyptian Journal of Radiology and Nuclear Medicine
Background In this study, we combined ultrasound and Doppler parameters to conclude the most accurate and applicable method for fetal lung maturity assessment. Thepurpose is to reduce risk of neonatal respiratory distress by assessment of fetal lung maturity through ultrasound and Doppler instead of amniocentesis. Results A total of 120 women were included. The ultrasound examination was performed at a gestational age ranging between 30 and 37 weeks and delivery occurred within 72 h from ultrasound. After birth, 19 fetuses were diagnosed with RDS. The ultrasound parameters assessed for fetal lung maturity showed varying sensitivity and specificity but presence of proximal tibial epiphyses showed the highest sensitivity (91%) and specificity (95%) followed by the presence of distal femoral epiphyses with 90% sensitivity and 84% specificity. The placental grade III maturity showed a sensitivity of 81% and 74% specificity followed by the presence of the amniotic fluid free-floating par...
The tap test—a rapid bedside indicator of fetal lung maturity
BJOG: An International Journal of Obstetrics & Gynaecology, 1991
Summary. The reliability of two rapid bedside tests of fetal lung maturity was investigated in 80 amniotic fluid samples. The results of the ‘tap’ test and those of the shake test were compared with the results of laboratory measurements of phospholipid profiles for fetal lung maturity. The tap test was found to be more reliable with a positive predictive value of 91% and a negative predictive value of 63%, whereas the shake test had a positive predictive value of 79% and a negative predictive value of 31%. The tap test was also more reliable in identifying fetuses with borderline lecithin/sphingomyelin ratios in the range 3.2–3.7:1.
American Journal of Obstetrics and Gynecology, 2011
We sought to develop a gestational age-independent sonographic parameter to characterize lung growth. STUDY DESIGN: Reported descriptors of lung growth, including lungto-head circumference (HC) ratio (LHR) and observed/expected LHR, were examined. A new index, the quantitative lung index (QLI) was derived using published data on HC and the area of the base of the right lung.
Interpretation of indices of fetal pulmonary maturity by gestational age
Paediatric and Perinatal Epidemiology, 1988
Amniotic fluid indices of fetal pulmonary maturity, including the lecithin/sphingomyelin (L/S) ratio and quantitative saturated phosphatidylcholine (SPC), are commonly employed to determine the risk of respiratory distress syndrome (RDS) in pregnancies complicated by premature labour, ruptured membranes, or uncertain duration of gestation. Despite consensus on the value and interpretation of results in these clinical settings, controversy remains regarding the use of routine amniocentesis and examination of amniotic fluid indices of fetal pulmonary maturity prior to repeat Caesarean section in the near or full-term gestation of reasonably certain dates.
Amniotic fluid lamellar body count: cost-effective screening for fetal lung maturity
Obstetrics & Gynecology, 1999
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.