Quantitative ultrasound analysis in evaluation of fetal lung maturity / 中国介入影像与治疗学

Objective To investigate the application value of DFY-Ⅱ ultrasound imaging analysis software in evaluation of fetal lung maturity in different pregnancy.Methods Totally 315 cases of healthy single pregnancies (24-41 weeks) were collected.The sonographic views of fetal right side sagittal plane were obtained.The echo intensity of fetal lung and liver were analyzed and the ratio was canculated with DFY-Ⅱ ultrasound imaging analysis software.Results The ratio of echo intensity from fetal lung and liver had positive correlation with gestational weeks (r=0.94,P＜0.05),the linear regression equation was Y=0.60+0.07X (r2 =0.883).Conclusion The ratio of echo intensity by fetal lung and liver analyzed with DFY-Ⅱ ultrasound imaging analysis software can be an effective method to evaluate fetal lung maturity.

Value of Doppler ultrasound in monitoring velocity waveforms in the fetal main pulmonary artery in patients with early onset severe preeclampsia / 中华超声影像学杂志

Objective To explore the change of Doppler velocity waveforms in the fetal main pulmonary artery in patients with early onset severe preeclampsia and to assess its value in fetal lung maturity.Methods A prospective study was conducted to analyze fetal main pulmonary artery velocity waveforms parameters including acceleration time(AT),ejection time(ET),acceleration time/ejection time (AT/ET),peak systolic velocity (PSV) in 30 cases of pregnant women with early onset severe preeclampsia.According to neonatal outcome,these cases were divided into respiratory distress syndrome (RDS) group (18 cases) and non-RDS group (12 cases).Each group was compared with 54 cases and 36 cases that were normal and had corresponding gestational age separately.Doppler parameters were compared between these two groups and their corresponding normal control groups.Results Gestational age at sonographic examination,gestational age at delivery and birth weight of neonates in RDS group were significantly lower than those in non-RDS group(all P ＜0.001).The value of AT,ET,AT/ET,PSV were lower in RDS group than those in gestational age-matched control group(all P ＜0.05),while there were no significant difference between non-RDS group and gestational age-matched control group(all P ＞ 0.05).Conclusions Doppler ultrasound monitoring fetal main pulmonary artery velocity waveforms to evaluate fetal lung maturity in patients with early onset severe preeclampsia has clinical application value.

Ultrasound Observation of Fetal Lung Maturity in Pregnant Women with Preeclampsia / 中国医科大学学报

Objective To study the sonographic features of fetal lung in normal and preeclampic pregnancies,with follow-up on the occurrence of neonatal respiratory distress syndrome (NRDS),as well as,examine the effects of preeclampsia (PE) on fetal lung maturity (FLM).Methods We collected data from 140 cases during the early pregnancy period (29 to ＜34 weeks),100 cases during the late pregnancy period (34 to 39 weeks),as well as 240 cases of normal pregnancies with the same gestational ages for the contwl group.Data included the parameters of fetal lung maturity measured by ultrasound and the incidence of NRDS postpartum.We analyzed the effects of PE on fetal lung maturity.Results The right fetal lung from the early onset PE group was significantly smaller than that of the normal group.There was no difference in the right lung area between the PE group and the normal group of the same gestational age.Compared with the normal group of the same gestational age,the LHR group had no difference in the early and late PE groups.The acceleration time/ejection time of the main pulmonary artery in the early and late PE group was significantly higher than that of the normal group.There was no difference in the incidence of NRDS among all the groups of the same gestational age.Conclusion PE has no significant effect on fetal lung function or maturation of the pulmonary tissues.Lung maturation may precede the same gestational age without PE.

Madurez pulmonar fetal: evaluación ecográfica, ¿es confiable?

El objetivo de la presente comunicación es revisar la importancia del tema de la madurez fetal mediante procedimientos no invasivos empleando los ultrasonidos en sus variantes de flujometria Doppler y escala de grises. Los autores destacan la importancia de precisar con la mayor exactitud el grado de madurez pulmonar alcanzada por el feto a la hora de tomar la decisión de interrumpir la gestación por diversas indicaciones. Todo ello con la finalidad de evitar las consecuencias de la prematuridad que incluyen el síndrome de dificultad respiratoria (SOR) del recién nacido ocasionado por la ausencia de surfactante pulmonar que pudiera inclusive llevarlo a la muerte. Coinciden los autores en que se trata de un diagnóstico multiparamétrico que tiene como punto de partida el cálculo de la edad gestacional a partir de un primer estudio ultrasonográfico realizado entre las 5 y 10 semanas, luego la evaluación de la impedancia vascular del lecho pulmonar por medio del Doppler, acompañado de otros parámetros tales como la madurez intestinal, el grado de corticalización cerebral, la presencia de núcleos de osificación, la edad biométrica fetal actual y la estimación del peso. Concluyen enfatizando que ante la duda y la existencia de un feto sano, con crecimiento adecuado, perfil biofísico y hemodinámico normal, la conducta más sensata es la de esperar la culminación de la gestación según los nuevos criterios que redefinen la duración del embarazo y que han sido propuestos por la ACOG.

The purpose of this communication is to review the importance of fetal maturity determination by non-invasive procedures using ultrasound Doppler velocimetry and grayscale. The authors emphasize the importance of precisely specifying fetal lung maturity when deciding to terminate pregnancyfor various indications in order to avoid consequences of prematurity including newborn's respiratory distress syndrome (ROS) due to absence of lung su rfactant that could lead even to death. The authors coincide that a multiparameter diagnosis of gestational age calculation starts from a first ultrasound study between 5 and 10 weeks, assessment of lung vascular impedance by Doppler accompanied by intestinal maturity, degree of cerebral corticalization, presence of nuclei ossification, current biometric fetal age and estimation of weight. They conclude emphasizing that in doubt and presence of a healthy fetus, with good growth, and normal hemodynamic biophysical profile, the more sensible course is to wait for the completion of gestation according to new criteria that redefine the duration of pregnancy and has been proposed by the ACOG.

TDx-FLM Test to Determine the Fetal Lung Maturity / 대한산부인과학회잡지

OBJECTIVE: Our purpose is to determine the optimal cutoff value for the TDx-FLM assay for predicting fetal lung maturity and its clinical efficiency. METHODS: We reviewed records of 81 pregnant women (117 fetuses), who had TDx-FLM assay performed from 1996 through 2000 at Ajou University Hospital. All were delivered between 28 and 37 weeks' gestation. Women treated with steroids after fetal lung maturity test were excluded in this study. In neonatal respiratory outcomes, result of fetal lung maturity was defined as neonates who were not affected by respiratory distress syndrome (RDS). All neonates were divided into mature and immature group according to their respiratory outcomes and clinical characteristics of both groups were evaluated. The predictive values for maturity and immaturity were calculated as previously defined. RESULTS: Among 117 newborns, RDS developed in 8 cases (immature group), and 109 cases were unaffected (mature group). In mature and immature group, mean gestational age was 35.0 weeks and 33.1 weeks (p=0.038), mean fetal birth weight 2313.4 gm and 2036.3 gm respectively (p=0.279). Preterm deliveries were due to preterm labor (32.1% vs 25.0%, p=0.676), premature rupture of membranes (11.9% vs 12.5% p=0.962), preeclamsia (17.4% vs 37.5%, p=0.384), intrauterine growth restriction (11.0% vs 0%, p=0.211), discordant twin (16.5% vs 0%, p=0.212) and other maternal complications (35.8% vs 37.5%, p=0.922) And also, frequencies of twin were 0% vs 64.2% (por=24.7 mg/g which gave a sensitivity 93.6%, specificity 87.5%, positive predictive value (PPV) 99.0%, negative predictive value (NPV) 50.0% and efficiency 93.1. CONCLUSION: The best cutoff value of TDx-FLM levels for assessment of fetal lung maturation was 24.7 mg/g in our study group.

TDx-FLM Test to Determine the Fetal Lung Maturity / 대한산부인과학회잡지

OBJECTIVE: Our purpose is to determine the optimal cutoff value for the TDx-FLM assay for predicting fetal lung maturity and its clinical efficiency. METHODS: We reviewed records of 81 pregnant women (117 fetuses), who had TDx-FLM assay performed from 1996 through 2000 at Ajou University Hospital. All were delivered between 28 and 37 weeks' gestation. Women treated with steroids after fetal lung maturity test were excluded in this study. In neonatal respiratory outcomes, result of fetal lung maturity was defined as neonates who were not affected by respiratory distress syndrome (RDS). All neonates were divided into mature and immature group according to their respiratory outcomes and clinical characteristics of both groups were evaluated. The predictive values for maturity and immaturity were calculated as previously defined. RESULTS: Among 117 newborns, RDS developed in 8 cases (immature group), and 109 cases were unaffected (mature group). In mature and immature group, mean gestational age was 35.0 weeks and 33.1 weeks (p=0.038), mean fetal birth weight 2313.4 gm and 2036.3 gm respectively (p=0.279). Preterm deliveries were due to preterm labor (32.1% vs 25.0%, p=0.676), premature rupture of membranes (11.9% vs 12.5% p=0.962), preeclamsia (17.4% vs 37.5%, p=0.384), intrauterine growth restriction (11.0% vs 0%, p=0.211), discordant twin (16.5% vs 0%, p=0.212) and other maternal complications (35.8% vs 37.5%, p=0.922) And also, frequencies of twin were 0% vs 64.2% (por=24.7 mg/g which gave a sensitivity 93.6%, specificity 87.5%, positive predictive value (PPV) 99.0%, negative predictive value (NPV) 50.0% and efficiency 93.1. CONCLUSION: The best cutoff value of TDx-FLM levels for assessment of fetal lung maturation was 24.7 mg/g in our study group.

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

Assessment of fetal lung maturity by free-floating particles in amniotic fluid and biparietal diameter by ultrasonography.

The accuracy of Free-floating particles (FFPs) and biparietal diameter (BPD) detected and measured by ultrasonography for assessment of fetal lung maturity were compared with the lecithin/sphingomyelin (L/S ratio) which was used as the gold standard. One hundred pregnant women in the lately third trimester who required amniocentesis for fetal lung maturity testing, from July 1998 to August 1999 at Siriraj Hospital, were included in this study. Ultrasonography was performed to evaluate the presence of FFPs in the amniotic fluid and the BPD was measured. Amniotic fluid for L/S ratio was obtained by amniocentesis. The presence of FFPs had a 58.3% specificity and a 41.7% false positive rate. A BPD value of at least 94 millimeters had 100% specificity and no false positives. When the presence of FFPs and a BPD value of at least 93 millimeters were used in combination, the test gave 100% specificity and no false positives. The presence of FFPS and a BPD value of at least 93 millimeters detected by real time ultrasonography may be used as predictive parameters to indicate fetal lung maturity.

Assessment of fetal lung maturity by multiple testing with shake test, tap test and OD 650.

Assessment of fetal lung maturity is of great importance in obstetric practice to plan for the future care and proper time for termination of pregnancy. At present, there are many methods used for screening for fetal lung maturity. A good screening test should be simple, easy to perform, rapid, inexpensive and be sensitive and specific. This study was a comparative study of fetal lung maturity assessment by using multiple testing: shake test, tap test and OD 650. These three tests were performed simultaneously and interpreted within 10-15 minutes. The results were compared with lecithin and sphingomyelin ratio (L/S ratio) which was used as the gold standard. L/S ratio > 2 was interpreted as “mature” in this study. Aminotic fluid samples wee obtained from women with uncomplicated pregnancies who underwent amniocentesis for fetal lung maturity testing with consent. All samples were uncontaminated by blood or meconium. The results, analysed from 185 samples studied, showed that the shake test, tap test and OD 650 gave a sensitivity of 79.3%, 87.1%, 76.6% and a specificity of 60.0%, 45.0% and 54.2% respectively, which were not statistically different (P>0.05, Cochran’s test). Screening for maturity using two or more tests gave a sensitivity of 82.7% and a specificity of 55.8% which were also not statistically different when compared with each test. In conclusion, shake test, tap test or OD 650 can be easily used as a simple and sensitive screening method for fetal lung maturity. Multiple testing, performing all three tests simultaneously, did not increase the sensitivity or specificity of the test and is not recommended. The choice of test at a screening method is therefore up to individual preference of depends on facilities available.

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.

Evaluation of fetal lung maturity by using free-floating particles in amniotic fluid ultrasonography.

The examination of amniotic fluid for the presence or absence of free-floating particles (FFPs) by real-time ultrasound was performed in 100 non-diabetic patients undergoing amniocentesis for maturity testing. A modified lecithin to sphingomyelin ratio (L/S ratio) was the gold standard of the test. The sensitivity and specificity were 97.6% and 62.5% respectively. The presence of FFPs had 93.2 positive predictive value and 83.3% negative predictive value. FFPs grade 2, 1, 0 had 100%, 70% and 16.7 positive predictive value respectively. The mean value of L/S ratio varied with the FFPs grading, with the mean of 5.09+ 2.48, 2.84 + 0.71, 2.02+ 0.01 in grade 2, 1 and 0 respectively. This study suggests that the presence of FFPs especially FFPs grade 2 on real-time ultrasound may be used to confirm fetal lung maturity.

Assessment of optical density on amniotic fluid in predicting fetal lung maturity.

The optical density (OD) of 107 amniotic fluids obtained by the amniocentesis after centrifugation at 450 x g or 2000 x g were measured at wave lengths varying from 500 to 650 nm. The OD was found to be lower at the centrifugation at 2000 x g than that at 450 x g and showed a reverse relationship to the wave lengths. In comparison with the foam test, OD measurements predicted the maturity of the fetal lung with less degree of accuracy and gave a higher false negative prediction was still relatively high. It was there fore concluded that OD measurements can not be used to replace the foam test because of their high degree of false negative prediction.