Research progresses of ultrasound in evaluation of fetal lung maturity / 中国医学影像技术

The most common cause of increased premature mortality and neonatal morbidity is lung immaturity. The evaluation of fetal lung maturity plays an important role in perinatal management. Prenatal evaluation of fetal lung maturity has become the key to improve the survival rate of newborns, especially preterm infants. Ultrasound has great value in prenatal assessment. The research progresses of ultrasound in evaluation of fetal lung maturity were reviewed in this article.

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.

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.

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.

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.

Amniotic Fluid Optical Density (AFOD) correlates with the lung maturity as well as complete maturity of the fetus A clinical observational study.

According to ACOG committee, complications of non-medically indicated (elective) deliveries between 37 and 39 weeks are faced with increased NICU admissions, transient tachypnea of thenewborn (TTN), respiratory distress syndrome (RDS), increased need for ventilator support, increased sepsis rates (suspected or proven) and higher incidence of newborn feeding problems and other transition issues. Cesarean sections done at less than 39 weeks gestation have increased risk of neonatal morbidity including respitory distress, hypoglycemia, sepsis, NICU admissions, hospitalization for more than 5 days, etc this study aims at correlating fetal maturity with amniotic fluid optic density.

Glucocorticoid in promoting fetal/neonatal lung maturity / 国际儿科学杂志

Perinatal glucocorticoid therapy has been proved to be effective on promoting fetal/neonatal lung maturity and has contributed to a dramatic improvement in the mortality and morbidity associated with neonatal respiratory distress syndrome.The underlying mechanisms studies are aimed primarily at accelerating the development of alveoli and pulmonary surfactant system.Meanwhile,a growing number of investigations focus on the side effects of perinatal glucocorticoid therapy on fetal/neonatal.Whether the repeat antenatal glucocorticoid and early postnatal glucocorticoid by intravenous injection is safe remains unclear.More studies are needed on the different route of giving glucocorticoid,the effect of different doses and their machanisms.This review presents the relevant information surrounding perinatal glucocorticoid therapy to enhance fetal/neonatal lung maturity,including clinical and animal studies over the last decades.

Morbilidad y mortalidad neonatal en pacientes con rotura prematura de membranas pretérmino / Neonatal morbidity and mortality in patients with premature rupture of membranes

Introducción: según la Organización Mundial de la Salud, aproximadamente el 40 % de los partos prematuros están precedidos de ruptura prematura de membranas. Objetivo: identificar la morbilidad y mortalidad neonatal de las pacientes que presentaron rotura prematura de membranas pretérmino entre las 28,0 y 32,6 sem en el Hospital Ginecoobstétrico "Ramón González Coro". Métodos: se realizó un estudio descriptivo retrospectivo de 45 gestantes con rotura prematura de membranas pretérmino, entre las 28,0 y 32,6 sem de edad gestacional, que ingresaron en el Hospital Ginecobstétrico Ramón González Coro, entre enero de 2006 y diciembre de 2008. Se utilizó el porcentaje, las frecuencias, datos de contingencia y medias. La información fue procesada en el paquete estadístico SPSS 11.5. Resultados: el 48,9 % pesó menos de 1 500 g; el 22,0 % presentó síndrome de distrés respiratorio y enfermedad de membrana hialina; el 60,0 % de los que continuaron con una conducta expectante por más de 8 días luego de culminado el tratamiento antimicrobiano tuvieron sepsis neonatal; el 50,0 % presentó enfermedad de membrana hialina luego de 8 días de administrados los inductores de la madurez pulmonar fetal; todos los fallecidos pesaron menos de 1 500 g. Conclusiones: aproximadamente la mitad de los recién nacidos tuvo un peso inferior a los 1 500 g. La enfermedad de membrana hialina y la sepsis neonatal fueron las complicaciones más frecuentes. Predominó la enfermedad de membrana hialina en los que concluyeron la terapia esteroidea por más de 8 días. La mortalidad neonatal fue significativa en los recién nacidos con peso inferior a 1 500 g.

Introduction: according to the World Health Organization, approximately 40 % of preterm births are preceded by premature rupture of membranes. Objective: to identify neonatal morbidity and mortality in patients who had premature rupture of membranes between 28.0 and 32.6 weeks at Ramón González Coro Maternity Hospital. Methods: a retrospective study was conducted in 45 pregnant women with preterm premature rupture of membranes between 28.0 and 32.6 wk gestational age, they were admitted to Ramón González Coro Maternity Hospital, from January 2006 to December 2008. Percentage, frequencies, and average data contingency were estimated. The information was processed using SPSS 11.5. Results: 48.9 % weighed less than 1 500 g, 22.0 % had respiratory distress syndrome and hyaline membrane disease, 60.0 % of those who continued with watchful approach for more than 8 days after completed antimicrobial treatment, had neonatal sepsis, 50.0 % had hyaline membrane disease after 8 days receiving inducers of fetal lung maturity, all dead cases weighed less than 1 500 g. Conclusions: about half of these infants weighing less than 1 500 g. Hyaline membrane disease and neonatal sepsis were the most common complications. Hyaline membrane disease was predominant in those who completed steroid therapy for more than eight days. Neonatal mortality was significant in infants weighing less than 1 500 g.

Modificaciones en el flujo sanguíneo del tronco de la arteria pulmonar en fetos prematuros que recibieron corticoides

Objetivos: Evaluar las modificaciones de la velocimetría Doppler en el flujo sanguíneo del tronco de la arteria pulmonar en fetos prematuros expuestos a corticoesteroides. Diseño: Estudio prospectivo. Institución: Instituto Latinoamericano de Salud reproductiva (ILSAR), Lima, Perú. Participantes: Madres con 29 a 36 semanas de edad gestacional y sus fetos. Intervenciones: En gestantes con 29 a 36 semanas de gestación que habían recibido corticoides para madurez pulmonar fetal, se hizo velocimetría Doppler del flujo sanguíneo del tronco de la arteria pulmonar de sus fetos. Principales medidas de resultados: Correlación de los cambios de la velocimetría Doppler con la madurez pulmonar en el neonato. Resultados: Los fetos prematuros que recibieron corticoides no tuvieron complicaciones respiratorias neonatales cuando el índice tiempo de aceleración/tiempo de desaceleración sistólico (TA/TD) fue igual o mayor a 0,57, cuyo valor se alcanzó en fetos con 33 semanas o más y con peso desde 2 000 g. Los valores de TA/TD luego de corticoides tuvieron una correlación estadística alta con las complicaciones respiratorias del RN (p<0,0001). Conclusiones: Después de aplicar corticoides para madurar el pulmón en fetos prematuros, se observó modificaciones en el flujo del tronco de la arteria pulmonar medidos con el índice TA/TD, con valores superiores a los observados para la misma edad gestacional en fetos sin corticoides. La diferencia fue altamente significativa desde la semana 33. El índice TA/TD del tronco de la arteria pulmonar es una herramienta útil para determinar madurez pulmonar.

Objectives: To determine changes in pulmonary artery blood flow Doppler velocimetry in preterm fetuses exposed to corticosteroids. Design: Prospective study. Setting: Instituto Latinoamericano de Salud Reproductiva (ILSAR), Lima, Peru. Participants: Mothers 29-36 weeks of gestation and their fetuses. Interventions: In fetuses of mothers 29-36 weeks of gestation who had received corticosteroids for maturation pulmonary artery blood flow Doppler velocimetry was performed. Main outcome measures: Correlation of Doppler velocimetry changes and neonate lung maturity. Results: Preterm fetuses that received corticosteroids did not present neonatal respiratory complications when systolic acceleration time/deceleration time (AT/DT) index was equal or over 0,57, value obtained in fetuses 33 weeks or more and weight over 2 000 g. AT/DT values following corticosteroids showed high statistical correlation with newborn respiratory complications (p<0,0001). Conclusions: Pulmonary artery blood flow measured with AT/DT index was modified after corticosteroids administration for preterm fetal lung maturation; values were superior to those observed for same gestational age fetuses without corticosteroids. Difference was highly significant starting at week 33. AT/DT index of the pulmonary artery stem is a useful tool to determine pulmonary maturity.

Prenatal assessment of normal fetal pulmonary grey-scale and lung volume by three-dimensional ultrasonography / 西安交通大学学报·英文版

Objective: To quantitatively analyze the fetal lung echo and right lung volume in the third trimester by real-time three-dimensional ultrasound (3-D US) and evaluate the feasibility of fetal lung maturity. Methods: A total of 732 women with normal singleton pregnancies between 28 and 42 weeks of gestation underwent ultrasound examination. The 3-D US equipment with a 3.5-5 MHz transabdominal transducer was used for the fetal biometric measurement. The echogenicity ratio between fetal lung and liver was compared. The fetal lung volume was calculated by the rotational multiplanar technique for volume measurement (VOCAL). Results: The right fetal lung volume increased with the increase of gestational age with a linear positive correlation (r = 0.884, P<0.01). After 34 weeks, the echogenicity ratio of fetal lung to liver was more than 1.1. Conclusion: The echogenicity of lung/liver and fetal lung volume could be used as normal fetal predictable indicators for fetal lung maturity.

Prenatal assessment of normal fetal pulmonary grey-scale and lung volume by three-dimensional ultrasonography / 药物分析学报

Objective To quantitatively analyze the fetal lung echo and right lung volume in the third trimester by real-time three-dimensional ultrasound (3-D US) and evaluate the feasibility of fetal lung maturity. Methods A total of 732 women with normal singleton pregnancies between 28 and 42 weeks of gestation underwent ultrasound examination. The 3-D US equipment with a 3.5-5MHz transabdominal transducer was used for the fetal biometric measurement. The echogenicity ratio between fetal lung and liver was compared. The fetal lung volume was calculated by the rotational multiplanar technique for volume measurement (VOCAL). Results The right fetal lung volume increased with the increase of gestational age with a linear positive correlation (r=0.884, P<0.01). After 34 weeks, the echogenicity ratio of fetal lung to liver was more than 1.1. Conclusion The echogenicity of lung/liver and fetal lung volume could be used as normal fetal predictable indicators for fetal lung maturity.

Evaluación de la morbi-mortalidad neonatal con el uso de esteroides prenatales / Neonatal morbidity and mortality evaluation in the prenatal steroids use

Antecedentes: Los esteroides prenatales han sido utilizados para reducir la frecuencia de complicaciones respiratorias neonatales. Anualmente se informan 13 millones de nacimientos prematuros en el mundo, el Instituto Nacional de Perinatología Isidro Espinosa de los Reyes informa el 19.7%. Objetivo: El objetivo del presente trabajo fue conocer el riesgo de utilizar uno o más esquemas de esteroides antenatales en amenaza de parto prematuro. Material y Métodos: Se trata de un estudio retrospectivo en un hospital de tercer nivel, del primero de enero del 2002 al 31 de diciembre del 2003, se incluyeron neonatos prematuros entre la semana 26 a 32 de gestación, cuyas madres recibieron uno o más esquemas de esteroides antenatales, dos dosis de 12 mg de betametasona intramuscular con intervalo de 24 horas o cuatro dosis de 6 mg de dexametasona intramuscular. Resultados: Se revisaron 108 expedientes que cumplieron con los criterios de inclusión, se dividieron en dos: grupo I, 69 neonatos con un solo esquema y grupo II con 39, con dos o más esquemas. La edad gestacional fue significativamente menor para el grupo I con 28 semanas (p = 0.001). La ruptura prematura de membranas de más de 24 horas tuvo mayor frecuencia en el grupo I: 65% de los neonatos de este grupo necesitaron intubación endotraqueal durante la reanimación al nacimiento, contra el 59% del grupo II. Aumentó el riesgo para septicemia en el grupo I. La principal causa de muerte en ambos grupos fue el choque séptico. El riesgo de muerte fue mayor para el grupo I, OR 3.57; IC 95%: 1.2 - 11.36. Conclusión: No se pudo demostrar que la utilización de más de un esquema de maduración pulmonar sea perjudicial para el neonato.

Introduction: Prenatal steroids have been used to reduce the frequency of neonatal respiratory complications. 13 million of preterm births are reported annually. Nineteen point seven percent of the births at The National Institute of Perinatology in Mexico City are preterm. We want to know the risks of antenatal corticosteroid therapy in pregnant women with preterm labor. Material and Methods: We conducted a retrospective study in a third level hospital between January first 2002 and December 31 2003. Neonates with gestational ages between 26 and 32 weeks whose mothers received one or more antenatal corticosteroids therapy schemes (2 doses of 12 mg of intramuscular betametasone with 24 hour interval or 4 doses or 6 mg of intramuscular dexamethasone) were included. Results: One hundred and eight clinical records were reviewed and divided into two different groups: Group I (n = 69) who received one antenatal steroid scheme and Group II (n = 39) with 2 or more antenatal steroids therapy schemes. Men gestational age was significantly lower, 28 weeks, in group I (p = 0.001). Premature rupture of membranes of 24 hour of duration or more was more frequent in group I and 65% of the neonates in this group required endotracheal intubation during neonatal reanimation and 59% of the neonates in group II. Required this maneuver. There was an increased risk of septicemia and death in group I. The principal cause of death in both groups was septic shock. The risk of death was higher in group I; OR 3.57 IC 95% 1.2,11.36. Conclusion: According to this results we were no able te demonstrate that more than one maturation treatment schedule were benefitial in any way to the neonates.

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.