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Role of Echogenic Amniotic Fluid Particles and Optical Density in prediction of Respiratory Distress Syndrome and Labor
Abstract
This study was aimed to correlate echogenic amniotic fluid particle size (AFPS) in late third trimester to fetal lung maturity and amniotic fluid optical density (AFOD) at labor. AFPS were measured with specified criteria by real time transabdominal USG (3.5MHz) while Amniotic Fluid Index (AFI) was measured during routine antenatal visits. The criteria for AFPS score which are taken into account are the amniotic fluid particle size, number and distribution. Serial AFPS measurements were done till onset of labor. AFPS was correlated to AFOD value at spontaneous labor in 123 women. Uncentrifuged fresh amniotic fluid samples were obtained during ARM/amniotomy and used for AFOD estimation at 650 nm. The mean AFPS and AFOD at onset of labor was found to be 5.14 ± 0.69 mm (3.67 – 6.7 CI 95%) and 1.03 ± 0.31 (0.35 -1.69 CI 95%) respectively in 116 women who delivered normal babies devoid of respiratory distress syndrome (RDS). Serial AFPS measurements showed a definite AFOD surge after a value in the region of 3.8 mm which is obtained culminating in onset of Labor. 28 women (24.1%) had dense clusters of free floating particles across the vertical pool in amniotic fluid with mean AFPS and AFOD of 5.6 ± 0.68 mm and 1.12 ± 0.21 respectively. In 123 women, AFPS < 3.8 mm had sensitivity of 85.74% and positive predictive value of 66.67% in predicting RDS. AFPS serves as a sonological marker for fetal lung maturity and labor. The range of AFOD values can be measured in terms of AFPS (r =0.6, F = 69.8, β= + 0.23, p < 0.001). Serial AFPS estimation predicts fetal maturity and onset of labor.
... Initially, they are few. The number, size, and distribution of the particles increase gradually and extend to other quadrants [11]. ...
... The role of amniotic fluid particles as a predictor of fetal lung maturity has been studied by several researchers including Ram and Ram [11]. For prediction of RDS, Ram and Ram [11] reported a higher sensitivity (85.74%) and a lower PPV (66.67%) compared to our findings. ...
... The role of amniotic fluid particles as a predictor of fetal lung maturity has been studied by several researchers including Ram and Ram [11]. For prediction of RDS, Ram and Ram [11] reported a higher sensitivity (85.74%) and a lower PPV (66.67%) compared to our findings. Differences in the procedure used (amniocentesis vs ultrasound) or an inter-observer variation could explain this discrepancy. ...
Background
In this study, we combined ultrasound and Doppler parameters to conclude the most accurate and applicable method for fetal lung maturity assessment. The purpose 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 particles with an 83% sensitivity and 63% specificity, while echogenic fetal thalamus showed 77% and 79% for sensitivity and specificity, respectively, for prediction of fetal lung maturity. By using the fetal biometry , we could report that a BPD between 82.8 and 93.5 mm, AC between 295 and 322 mm, and FL (62.7-72.1 mm) correlated with mature fetal lungs. Regarding Doppler indices , increased resistive index of umbilical artery > 0.69 and of pulmonary artery > 0.78 correlated with neonatal RDS while fetuses with UtA RI values between 0.43 and 0.66 noticed in RDS vs (0.42-0.57) in the non-RDS. MCA RI values are also higher in RDS 0.77–0.88 vs 0.74–0.79 in non-RDS.
On the other hand, analysis of colon grading and fetal lung echogenicity in relation to liver showed no significant value in the assessment of fetal lung maturity.
Conclusion
Ultrasound and Doppler showed good predictive value and accuracy and is considered a valuable non-invasive procedure in assessment of fetal lung maturity. However, no single parameter alone could show a definitive sign
... AFPS acts as a sonological marker for fetal lung maturity and labor . 16 ...
... The ability to read newspaper headlines through amniotic fluid in a test tube is just one of many indicators of foetal lung maturity that has been studied in the past. Trimester to trimester, the particles' origin could change [9] . The development of the foetus' lungs can be evaluated in real time using ultrasound by using free floating particles (FFPs) that look like snowstorms or blizzards in the amniotic fluid. ...
... Ram et al. [18] assessed the amniotic fluid particles and its predictive value for fetal lung maturity and found a sensitivity of 85.74% which was higher than this study findings and PPV of 66.67% higher than this study which was 15.4% in the prediction of RDS. This variation might be attributed to the difference in the used technique (amniocentesis versus ultrasound) or inter-observer variations. ...
... [24][25][26] Exact measurements of AFOD is possible in AFI value of 9-16. 27 Ram et al reported mean optical density of 1.03±0.31 in babies devoid of RDS. 28,29 Babies With AFOD 0.98±0.27 ...
Background: Respiratory distress is the common cause of neonatal morbidity and mortality. Babies born even at 40 weeks of gestation developed respiratory distress. The maturity of newborn is independent of gestational age and birth weight of newborn. In this study amniotic fluid optical density (AFOD) is correlated with the functional maturity of newborn.Methods: In this study, hundred singleton pregnant women who underwent first trimester scan and crown rump length estimation, and who were on spontaneous labor were selected for this observational study. Under aseptic precautions AF samples were collected while doing amniotomy with 2 ml disposable syringe, also collected during caesarean section after careful hysterotomy from the bulging membranes. Amniotic fluid optical density studied with spectrometer at 650 nm. Birth weights were recorded for all the babies. Babies are also looked for the respiratory distress, NICU admission.Results: In this study, respiratory distress was reported in 28% of newborns whereas 72% of newborns did not have distress. In the present study, 27% of newborns were admitted in NICU where as 73% of the newborns were on mother’s side following delivery. Babies with AFOD 0.98±0.27 were functionally mature, skin was pleased brown in colour with little vernix, none of them had respiratory distress. Amniotic fluid optical density <0.4 developed respiratory distress.Conclusions: Amniotic fluid optical density is a simple method to assess the functional maturity of newborn.
... Other studies recorded different values. Ram SHS and Ram S. (24) assessed the amniotic fluid particles and its predictive value for fetal lung maturity and found a sensitivity of (85.74%) which was higher than our finding and PPV of (66.67%) lower than ours (93.3%) in the prediction of RDS. This variation might be attributed to the difference in the used technique (amniocentesis versus ultrasound) or inter-observer variations. ...
... Other studies recorded different values. Ram SHS and Ram S. (24) assessed the amniotic fluid particles and its predictive value for fetal lung maturity and found a sensitivity of (85.74%) which was higher than our finding and PPV of (66.67%) lower than ours (93.3%) in the prediction of RDS. This variation might be attributed to the difference in the used technique (amniocentesis versus ultrasound) or inter-observer variations. ...
Objective: to evaluate the value of ultrasonic fetal thalamic echogenicity and epiphyseal ossification centers of femur and tibia as signs of fetal lung maturity. Methods: one hundred pregnant women, at their 34-42 weeks of gestation were included in this prospective study. Ultrasound examination of biparietal diameter, echogenicity of the thalamus, ossification centers of distal femur epiphyses (DFE) and proximal tibia epiphyses (PTE), amniotic fluid vernix and placental changes were performed. The outcome measures were fetal weight, Apgar score at 1 & 5 minutes, admission to neonatal intensive unit & duration, and signs of respiratory distress syndrome (RDS). Results: the presence of PTE by ultrasound as sign of fetal lung maturity had a higher specificity, accuracy, and positive predictive value than DFE and thalamic echogenicity (91.7% versus 75% and 50% for specificity), (95% versus 92.0 and 77.0% for accuracy) and (98.8% versus 93.5% and 95.8% for PPV respectively). The sensitivity of PTE is 95.5% which is lower than DFE (97.7%) but higher than the thalamic echogenicity (77.3%). Conclusion: the use of thalamic echogenicity and epiphyseal ossification centers in the distal femur and proximal tibia by ultrasound were valuable for a more accurate assessment of fetal lung maturity.
... All these babies were fully functionally mature, and none of them developed RDS. It appears that, the concept of 'individual term for each fetus' is also applicable to women with GDM 4, 8 . ...
... While newer investigation has been focused on correlation between echogenic amniotic fluid particle size in late trimester and fetal lung maturity (6,7), the present article investigates the causes of hyperechogenisity of amniotic fluid. ...
Introduction: The incidence of very echogenic amniotic fluid on ultrasonographic examination at term pregnancy is very low and its causes and significance in outcome of pregnancy are not well- understood. In previous studies, meconium was considered to be an important cause of very echogenic amniotic fluid and follow-up with amniocentesis and fetal well-being tests were recommended; however, in recent studies vernix caseosa has been identified to be an important cause. As a result, termination of pregnancy should not be performed due to discovery of ultrasonographic echogenic amniotic fluid because it is not associated with adverse pregnancy outcomes. Case Presentation: We report a single term pregnancy with very echogenic amniotic fluid diagnosed by ultrasonography that was terminated by cesarean section. Conclusions: There were no adverse outcomes for the mother or neonate and the amniotic fluid was clear at the time of delivery.
... While newer investigation has been focused on correlation between echogenic amniotic fluid particle size in late trimester and fetal lung maturity (6,7), the present article investigates the causes of hyperechogenisity of amniotic fluid. ...
Objective: To assess the trend of rise in Amniotic Fluid Optical Density (AFOD) with the onset of spontaneous term labor. Methods: Amniotic Fluid (AF) samples collected by amniocentesis for lung maturity assessment in 12 preterm labor subjects were utilized for AFOD estimation. After successful tocolysis and continuation of pregnancies, AFOD estimations were repeated when women presented with labor pains again before 37w+6days. AF samples were also collected while doing amniotomy at spontaneous labor in all subjects. Un-centrifuged fresh AF samples were used for AFOD estimations with colorimeter at 650nm. Babies were evaluated for functional maturity in terms of RDS, color of the skin, and adherence of vernix caseosa to skin surface at birth. Results: Among these 12 subjects the CRL gestational age at delivery ranged from 35w+3days to 42w+0days. The AFOD values at amniotomy ranged from 0.74 to 1.54. In 11 subjects who underwent repeat amniocentesis we could observe a slow and prolonged rise in AFOD till a value around 0.40 was reached. After this value, the AFOD rose rapidly like a surge, which coincided with the onset of spontaneous labor. All babies born were functionally fully mature irrespective of gestational age and birth weight. In 6 subjects the duration of surge was observed to range from 6 to 10 days. Conclusion: There was a definite surge of AFOD which coincided with completion of fetal functional maturity and onset of spontaneous labor. All these factors occurring at different gestational ages with different fetuses indicate individualized term gestation for each fetus.
Objective: To establish the correlation between the
Amniotic fluid (AF) Optical density (OD) at the
onset of spontaneous labor and the functional
maturity, gestational age and birth weight of the
newborn.
Methods: Uncentrifuged fresh amniotic fluid
samples from 360 singleton pregnancies were
collected during artificial rupture of membranes or
amniotomy at LSCS after onset of labor for AFOD
estimation at 650 nm .
Results: The mean AFOD at spontaneous labor
was found to be 0.98±0.27 (n=360). The study
population was divided into 7 different groups
according to gestational age (GA) (35 1/7 -36 wks,
36 1/7-37wks, 37 1/7-38 wks, 38 1/7-39 wks, 39
1/7-40 wks , 401/7-41wks, and above 41 wks of
GA respectively). In different GA groups, the mean
AFOD at spontaneous labor ranged from
0.50±0.13 to 1.03±0.24. Between any two groups
among 2 to 7 (i.e. after 36 wks GA) when cases of
respiratory distress syndrome (RDS) was
excluded, there is no essential change in mean
AFOD values (range 0.85 to 1.03). The results
were same after adjusting for birth weights. All the
babies delivered at AFOD value of mean ± SD
0.98 ±0.27 (0.40 to 1.55 CI 95 %) ,were fully
functionally mature and did not develop RDS.
Babies born with AFOD < 0.40 (n=8) had varying
degrees of RDS with birth weights ranging from
2300 to 3000 gms. Also they had more vernix on
their body than the non RDS babies The mean
birth weights progressively increased from group 1
to 7.
Synopsis: Spontaneous normal labor takes
place with complete fetal functional maturity at an
optimum AFOD value of 0.90 irrespective of the
GA and birth weight in our study population. The
correlation of AFOD with functional maturity
supports the concept of individual term
In this study, we aimed to analyse the clinical features of the third-trimester pregnant women, with echogenic amniotic fluid and to compare their obstetric and neonatal outcomes with pregnant women with normal amniotic fluid echogenicity. This case-control study was conducted in a tertiary antenatal care centre. A total of 560 term (37–42 weeks of gestation) singleton women; 280 with echogenic particles in amniotic fluid and 280 with clear amniotic fluid, who delivered within 24 h after the ultrasound scan were evaluated. The women in the two groups were similar in terms of age, parity, body mass index, foetal birth weight, and gestational age. More patients in the particulate amnion group had lower Apgar scores (
This article reports a stable vessel object tracking method for the treatment of twin-to-twin transfusion syndrome based on our previous 2 DOF endoscope. During the treatment of laser coagulation, it is necessary to focus on the exact position of the target object, however it moves by the mother's respiratory motion and still remains a challenge to obtain and track the position precisely. In this article, an algorithm which uses features from accelerated segment test (FAST) to extract the features and optical flow as the object tracking method, is proposed to deal with above problem. Further, we experimentally simulate the movement due to the mother's respiration, and the results of position errors and similarity verify the effectiveness of the proposed tracking algorithm for laser ablation endoscopy in-vitro and under water considering two influential factors. At average, the errors are about 10 pixels and the similarity over 0.92 are obtained in the experiments.
Proteomics helps to understand the basic biological processes critical to normal cellular functions as well as the development of diseases. It identifies the essential components of these processes and exploits these components as targets in the development of new methods to prevent or treat diseases. Proteomics, although in an infancy stage in India, has the potential to complement and further enlarge the wealth of information in medicine, especially in the field of cancer. This article reviews the recent progress in proteomic techniques and their applications in the field of obstetrics and gynecology.
In order to investigate the role of amniotic fluid cells (AFC) in the establishment of feto-maternal immune relationship, we evaluated their phenotype and capacity to produce cytokines.
CK 7-8, human leukocyte antigen (HLA)-I, HLA-DR, HLA-G, CD1d, CD34, CD45, CD14 surface antigens expression and the intracellular production of IL-4, IL-6, IL-8, IL-10, IL-12, interferon-gamma and tumor necrosis factor-1 were studied in cultured AFC and in eight samples immediately after amniocentesis using flow cytometry. IL-6 and IL-8 were detected by ELISA in all amniotic fluids and in all culture supernatants. Moreover, IL-6 and IL-8 mRNA were tested in nine samples.
Cultured AFC express HLA-I, HLA-G and CK 7-8 and are able to produce IL-6 and IL-8, confirmed by presence of their mRNA. We quantified IL-6 and IL-8 levels in all amniotic fluids and in all supernatants.
Surface antigen expression of AFC are not specific of immune cells, but AFC are able to produce cytokines and we can postulate that they may participate in mechanisms involved in normal as well as pathological pregnancy.
Acne vulgaris is a self-limiting skin disorder primarily seen in ado- lescents, whose etiology appears to be multifactorial. Immunologi- cal factors including interleukins, epidermal growth factor, trans- forming growth factor, and extracellular products produced by the acne-causing organism, Propionibacterium acnes, play significant roles in acne pathogenesis. Sebaceous gland secretions also ap- pear to be important as sebum itself is comedogenic and initiates inflammation when exposed to dermal tissue. These immunologic factors in light of recent studies on retinoids are significant in treat-
Interleukin 1 (IL-1) immunoreactivity in sebaceous glands was studied in paraffin sections of normal human skin. A panel of antibodies against IL-1 alpha and beta was tested using an immunoperoxidase labelling method. All the antibodies showed a similar specific labelling pattern: both glandular and ductal cells were immunoreactive for both IL-1 alpha and beta, provided optimal tissue fixation was used.
A prospective study was performed to examine the hypothesis that sonographically homogeneous echogenic amniotic fluid (AF) may provide a marker for the presence of meconium-stained AF. Twenty term gestations in which homogeneous echogenic AF was demonstrated sonographically were compared with 40 cases with sonographically clear AF. Two cases in the study group had meconium-stained AF at delivery. All of the controls had clear fluid by amniocentesis (performed for lung maturation studies) immediately after the sonographic examination. Thus, homogeneous echogenic AF had a sensitivity of 100%, a specificity of 69%, a positive predictive value of 10%, and a negative predictive value of 100% in detecting meconium. We conclude that homogeneous echogenic AF does not necessarily detect meconium-stained AF.
The regulatory signals responsible for the increased biosynthesis of prostaglandins during parturition have not been established. Interleukin-1 (IL-1) is capable of stimulating prostaglandin production by intrauterine tissues and is an inflammation mediator. It has been postulated as a signal for the onset of labor in the setting of intrauterine infection. A study was designed to determine if spontaneous labor at term was associated with changes in IL-1 activity in amniotic fluid. Such fluid was retrieved from 41 women in labor and from 39 women who were not in labor at term. Immunodetectable IL-1 beta was present in 22 of the 41 women in labor but in only 8 of the 39 women without labor. IL-1-like bioactivity was not different between the two groups at a dilution of 1:4, but at dilutions of 1:12, 1:36 and 1:108, amniotic fluid from women in labor had significantly higher bioactivity than that from women not in labor. A significant correlation was found between the bioassay and immunoassay results. Our data show that inhibitors of IL-1 bioactivity are present in amniotic fluid and suggest that in a subset of laboring women at term, an inflammatory reaction may play a role in triggering the onset of parturition.
Epidermal growth factor (EGF)/alpha-transforming growth factor (alpha-TGF) concentrations were measured in amniotic fluid by radioreceptor assay in non-laboring and laboring patients at term. The median concentrations of EGF/alpha-TGF were 1.28 ng/ml and 5.0 ng/ml in non-laboring and laboring patients respectively (p less than 0.05, Wilcoxon test). EGF was then incubated with amnion cells in monolayer culture to ascertain the effect of this hormone on the release of prostaglandin E2. Experiments were carried out in quadruplicate in 11 separate primary amnion-cell cultures (EGF was used at 1 ng/ml and 5 ng/ml, respectively). An increased release of prostaglandin E2 into the media was found. The response was concentration-dependent (p less than 0.01). We suggest that there may be a role for EGF in the mechanism of human parturition.
Amniocentesis for the determination of fetal lung maturity is associated with some morbidity, and so the prediction of a mature fetus by noninvasive means could be useful in managing certain high-risk patients. In the first portion of this study, 467 amniotic fluid specimens were classified into one of five groups based on the turbidity and particulate matter present. The mean lecithin: sphingomyelin (L/S) ratios and the proportion of mature US values increased with increasing turbidity of the amniotic fluid. In the second portion of this study, the presence of amniotic fluid freefloating particles (FFPs) detected by real-time ultrasound was correlated with fetal lung maturity. When FFPs were present, the W S was uniformly mature, but when FFPs were absent, the LIS was mature in 74% of patients (P < 0.01). Among the patients in whom the LIS ratios were mature, 39/110 were associated with positive FFPs (sensitivity = 35%). This preliminary study suggests that the presence of FFPs on real-time ultrasound could be used to confirm fetal lung maturity.
Supported in part by NIH USPHS grants M01 RR00210 and 1P50 HD11089
Fetal pulmonary maturity is generally determined by analyzing amniotic fluid for surfactants. This task is accomplished by lipid extraction of the fluid and resolution, identification and quantitation of the isolated lipids with thin-layer chromatography. These methods are lengthy, cumbersome and often not available on demand. A quick, simple, reliable and economical test therefore would be highly desirable. We have been able to correlate an optical density (OD) reading of amniotic fluid at 650 nm greater than or equal to 0.15 with the absence of hyaline membrane disease (HMD). For 428 fluids in which an OD reading of greater than or equal to 0.15 was found and delivery occurred within 48 hours, HMD was present in only two infants. The accuracy of the test was 99.53% , with a false-positive rate of 0.47%. With the use of this simple and accurate test one can satisfy the requirement of an on-demand test to determine fetal pulmonary maturity.
This prospective study of 131 pregnant women was designed to determine the incidence and significance of floating particles in amniotic fluid. Floating particles ranging in size from 1 to 5 mm were seen in the amniotic fluid of pregnant women at 15 to 40 weeks' gestation. Since vernix is rarely present before 35 weeks' gestation, a source other than flakes of vernix must be sought to explain the floating particles in amniotic fluid in early gestations. There was no significant difference in the sizes or numbers of particles at different gestational ages (from 15 to 40 weeks). Therefore, it is concluded that ultrasonographic demonstration of floating particles in amniotic fluid cannot be considered an indicator of fetal maturity.
The objective of this study was to determine the rate of ultrasound-detected free-floating particles in amniotic fluid during the early second trimester and their relationship with maternal serum alpha-fetoprotein (MSAFP) in patients with normal amniotic fluid alpha-fetoprotein (AFAFP). Ninety-eight consecutive patients undergoing second-trimester amniocentesis for various indications were prospectively studied. Before undergoing amniocentesis, each patient had a level II ultrasound examination and evaluation of the presence of free-floating particles. A subjective estimate of the particle amount and measurement of the size of the largest particle seen were made. Patients were stratified into three groups according to their MSAFP level (low, normal, high). Statistical significance of results was assessed by analysis of variance and multiple comparison procedure, and by nonparametric procedures, as appropriate. MSAFPs (mean +/- 1 SD) were 0.41 +/- 0.18 and 4.88 +/- 2.22 multiples of the median for the low and the high groups, respectively. All AFAFPs were within normal limits. Ninety-four percent of patients with high MSAFP had free-floating particles in amniotic fluid as compared to 43% in the low and normal groups (p < 0.01). Patients with high MSAFP had significantly greater density and size of particles. The presence of ultrasound-detected free-floating particles in amniotic fluid of normal patients during the early second trimester may preclude its use as a reliable indicator for fetal lung maturity, or suggest that the source of these particles may differ by trimester. High MSAFP is significantly correlated with the ultrasonographic appearance of free-floating particles, as well as with larger size and higher amount.
Very echogenic amniotic fluid has been variably attributed to meconium, blood, or vernix caseosa. However, most previous reports have been case reports, and most cases have not had proof by amniocentesis. In a larger series of patients with proof by amniocentesis, we sought to determine the relative frequency of these substances as causes of very echogenic amniotic fluid. We retrospectively identified obstetric sonograms in which the amniotic fluid was homogeneously filled with innumerable echogenic particles. The cause of the increased echogenicity was determined by fluid appearance at amniocentesis. Of 86 cases identified, immediate proof by amniocentesis was available in 19 patients for whom the gestational age ranged from 32.8 to 39.4 weeks. Vernix was present in 18 (95%) patients and meconium in one (5%) patient. Very echogenic amniotic fluid in the third trimester is most often due to vernix and infrequently due to meconium. This sonographic finding is not a reliable indicator of meconium or blood in amniotic fluid and should not typically alter antenatal management.
During the second trimester of pregnancy, the presence of free-floating particles in the amniotic fluid on ultrasonography has been associated with aggregates of cells or fetal blood and with unexplained elevation of maternal serum alpha-fetoprotein and the later development of abruptio placentae and fetal distress. During the third trimester, particulate amniotic fluid is thought to represent meconium or vernix.
An unusual, ultrasonically dense appearance of the amniotic fluid was noted prior to 18 weeks of pregnancy in two asymptomatic women who carried exencephalic fetuses. In both cases, prenatal evaluation of the amniotic fluid suggested that the free-floating particles were due to the presence of blood.
A detailed ultrasonographic evaluation should be undertaken should dense amniotic fluid be detected early in pregnancy because this sign may help in the early diagnosis of fetuses with congenital malformations likely to bleed.
Corticotropin releasing hormone, a hypothalamic neuropeptide, plays a major role in regulating pituitary-adrenal function and the physiologic response to stress. During pregnancy corticotropin-releasing hormone is synthesized in large amounts by the placenta and released into the maternal and fetal circulations. Various endocrine, autocrine, and paracrine roles have been suggested for placental corticotropin-releasing hormone. The aim of this study was to prospectively assess the relationship between maternal plasma concentrations of corticotropin-releasing hormone in the early third trimester of pregnancy and the length of gestation in two groups of deliveries, with and without spontaneous labor.
In a sample of 63 women with singleton intrauterine pregnancies, maternal plasma samples were collected between 28 and 30 weeks' gestation and corticotropin-releasing hormone concentrations were determined by radioimmunoassay. Each pregnancy was dated on the basis of last menstrual period and early ultrasonography. Parity, antepartum risk conditions, presence or absence of spontaneous labor, and birth outcomes were abstracted from the medical record.
Maternal corticotropin-releasing hormone levels between 28 and 30 weeks' gestation significantly and negatively predicted gestational length (P < .01) after adjustment for antepartum risk. Moreover, subjects who were delivered preterm had significantly higher corticotropin-releasing hormone levels in the early third trimester (P < .01) than did those who were delivered at term. In deliveries preceded by spontaneous onset of labor, maternal third-trimester corticotropin-releasing hormone levels significantly and independently predicted earlier onset of labor (P < .01) and preterm labor (P < .05), whereas in deliveries effected by induction of labor or cesarean delivery, maternal corticotropin-releasing hormone levels were a marker of antepartum risk but not a statistically independent predictor of gestational length.
These findings support the premise that placental corticotropin-releasing hormone is potentially implicated in the timing of human delivery in at least two ways. First, placental corticotropin-releasing hormone may play a role in the physiology of parturition. Premature or accelerated activation of the placental corticotropin-releasing hormone system, as reflected by precocious elevation of maternal corticotropin-releasing hormone levels, may therefore be associated with earlier onset of spontaneous labor and resultant delivery. Second, placental corticotropin-releasing hormone may be a marker of antepartum risk for preterm delivery and therefore an indirect predictor of earlier delivery. The implications of these findings are discussed in the context of the neuroendocrinology of placental corticotropin-releasing hormone and human parturition. Furthermore, the role of corticotropin-releasing hormone as a possible effector of prenatal stress in producing alterations in the timing of normal delivery is detailed.
To study the changes in concentrations of serum hyaluronic acid in uncomplicated human pregnancies.
We determined the concentrations of serum hyaluronic acid, using a specific enzyme-linked immunosorbent assay, in 70 nonpregnant women, 250 women during their pregnancies, and 68 women at the time of parturition. Results were analyzed for statistical significance with Scheffé test for multiple comparisons.
During pregnancy, mean (+/- standard deviation) serum hyaluronic acid levels were 11.4 +/- 4.5, 13.6 +/- 2.8, 20.6 +/- 1.5, and 46.9 +/- 7.9 ng/mL at 5-14 (n = 47), 15-26 (n = 46), 27-37 (n = 58), and 38-40 (n = 99) weeks' gestation, respectively. Pregnant women in labor (n = 68) had significantly higher levels (100.4 +/- 11.3 ng/mL) than did women at term but not in labor (P < .01).
Maternal serum hyaluronic acid concentrations increase as pregnancy progresses and serum levels increase significantly at term. Hyaluronic acid may be associated with cervical ripening during parturition.
The development of amniotic fluid turbidity during the third trimester is a known marker of fetal lung maturity. We hypothesized that this turbidity results from detachment of vernix caseosa from the fetal skin secondary to interaction with pulmonary-derived phospholipids in the amniotic fluid. To test this hypothesis, we exposed vernix to bovine-derived pulmonary surfactant over a physiologically relevant concentration range. Ten milligrams of vernix was evenly applied to the interior walls of 1.5-mL polypropylene microfuge tubes. Surfactant phospholipids were added to the tubes followed by slow rotation at 37 degrees C overnight. The liquid was decanted and spectrophotometrically analyzed at 650 nm to detect solution turbidity due to vernix detachment and/or emulsification. Increasing concentrations of surfactant phospholipids produced a dose-dependent increase in solution turbidity. A phospholipid mixture closely approximating natural pulmonary surfactant but devoid of surfactant-associated proteins yielded no increase. In other studies, the flow properties of vernix were studied in a Haake flow rheometer at 23 degrees C and 37 degrees C. There was a marked temperature-dependent effect with lower stress required to elicit flow at 37 degrees C compared with 23 degrees C. This temperature dependence was also demonstrated in the turbidity assay with a 124% increase in turbidity at body temperature compared with room temperature. We conclude that under in vitro conditions, pulmonary surfactant interacts with vernix resulting in detachment from a solid phase support. We speculate that in utero, this phenomenon contributes to the increase in amniotic fluid turbidity that is observed near term.
This study was undertaken to determine whether obstetric factors affect the concentrations of matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 in the amniotic fluid.
We prospectively collected amniotic fluid samples from 109 women at various stages of pregnancy and labor and determined matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 concentrations by means of enzyme-linked immunosorbent sandwich assay systems. With multiple regression analysis we evaluated relationships between amniotic fluid matrix metalloproteinase 9 concentration and tissue inhibitor of metalloproteinase 1 concentration and the following factors: gestational age, presence of labor, cervical dilatation, membrane status, presence of clinical chorioamnionitis, and microbial colonization of the amniotic fluid.
The detectable presence of amniotic fluid matrix metalloproteinase 9 was independently associated with intra-amniotic infection, labor, cervical dilatation, and spontaneous rupture of membranes. Chorioamnionitis and amniotic fluid matrix metalloproteinase 9 concentrations were correlated with tissue inhibitor of metalloproteinase 1 levels.
Intra-amniotic infection, advanced labor, and rupture of membranes before the onset of labor were independently associated with the presence of matrix metalloproteinase 9 in the amniotic fluid. Both pathologic and physiologic processes appear to produce shifts in the balance between degradation and synthesis of the extracellular matrix.
To determine interleukin-6 and interleukin-8 levels in amniotic fluid, retroplacental blood and maternal serum and relate these values with cervical dilatation in term labor.
Prospective study. n=78 healthy women undergoing term cesarean section, divided into four groups: controls, n=42, (elective cesarean section; no contractions, membrane rupture or cervical dilatation); latent labor, n=12, (latent phase labor; cervix <2 cm dilated); established labor, n=12, (active labor, cervix 2-5 cm); advanced labor, n=12, (active labor, cervix >5 cm). Interleukin-6 and interleukin-8 were determined by ELISA (pg/ml), placenta and placental bed biopsy examined histopathologically, and amniotic fluid also microbiologically. Results were expressed as median and ranges or mean and standard deviations, as appropriate. For statistical analysis, Mann-Whitney U-tests or Kruskal-Wallis tests were used as applicable (Statview 4.5). Power and linear regression analyses were performed. p<0.05 was considered significant, p<0.001 highly significant.
Compared with controls, IL-6 and IL-8 increased significantly with cervical dilatation in all compartments tested for almost all labor groups (p<0.05 to p<0.0001). Significant changes were also seen between latent and advanced labor groups in some compartments (p<0.05), but not between established and advanced labor groups. Intrauterine infection was excluded in any of the patients clinically and on histopathological or microbiological analysis of placentae and amniotic fluid.
In term labor without intraamniotic infection, interleukin-6 and interleukin-8 at the fetomaternal interface and in maternal serum rise significantly with cervical dilatation. These cytokines could be used as markers of active labor if vaginal examination is not applicable.
To describe the association between echogenic amniotic fluid and first-trimester fetal acrania.
Nine fetuses with acrania were examined between 11 weeks' and 13 weeks 6 days' menstrual age for the presence of echogenic free-floating particles in the amniotic fluid. Cases were classified into 3 types according to the echogenicity of the amniotic fluid: similar to (type 0), slightly greater than (type 1), and clearly more echogenic than (type 2) that of the extracelomic fluid.
In 1 pregnancy, no free-floating particles were identified (type 0). In 6 cases, small free-floating particles scattered within the amniotic cavity were identified, making the amniotic fluid slightly more echogenic than the extracelomic fluid (type 1). In the remaining 2 cases, the amniotic fluid was homogeneously and clearly more echogenic than the extracelomic fluid (type 2).
A high percentage (89%) of fetuses with acrania had echogenic amniotic fluid, suggesting that this finding could potentially be used as a marker of fetal acrania in the first trimester. This finding also supports the hypothesis of the transition from acrania to anencephaly, with the unprotected brain undergoing progressive destruction from the first trimester, leading to the classic finding of anencephaly in the second trimester.
The purpose of this study was to examine the relationship between preterm birth and 22 single nucleotide polymorphisms in genes that encode cytokines and mediators of apoptosis and host defense.
Two hundred two white women with a spontaneous preterm birth of <35 weeks of gestation were compared with 185 white women with term births. Genotyping was performed with polymerase chain reaction and sequence specific primers. Multivariable analyses included demographic and genetic variables.
Alcohol (multivariable odds ratio, 2.3; P = .001] and substance use (multivariable odds ratio, 3.7; P = .01) were associated with preterm birth at <35 weeks of gestation. Smoking (multivariable odds ratio, 2.3; P = .03), haplotypes IL10 -1082A/-819T/-592A (multivariable odds ratio, 2.1; P = .04), tumor necrosis factor ( TNF )+488A/-238G/-308G (multivariable odds ratio, 2.4; P = .04), and IL4 -509C/C (multivariable odds ratio, 3.4; P = .02), and the presence of MBL2 codon 54Asp (multivariable odds ratio, 2.3; P = .02) were associated independently with preterm birth at <29 weeks of gestation. Homozygosity for IL10 -1082G/-819C/-592C haplotype (multivariable odds ratio, 1.9; P = .02) was more common in women with preterm premature rupture of membranes.
Polymorphisms in immunoregulatory genes may influence susceptibility to preterm birth or premature rupture of membranes.
We sought to determine whether midtrimester amniotic fluid levels of matrix metalloproteinase-8 were associated with subsequent preterm premature rupture of membranes.
We conducted a case-control study examining 57 asymptomatic women who underwent genetic amniocentesis from 14 to 21 weeks' gestation and subsequently had preterm premature rupture of membranes (<35 wk) and 58 women with subsequent term delivery. Measurement of total matrix metalloproteinase-8 level in amniotic fluid was conducted using a commercially available enzyme-linked immunosorbent assay and association with preterm birth due to preterm premature rupture of membranes was assessed.
The overall distribution of matrix metalloproteinase-8 concentrations was similar in women who had preterm premature rupture of membranes and term controls (median 2.39 ng/mL, 25th to 75th percentile 1.1-10.1 vs 2.37 ng/mL, 25th to 75th percentile 1.5-4.7, P = .94). However, 26% of women who had preterm premature rupture of membranes had a matrix metalloproteinase-8 concentration above the 90th percentile (8.7 ng/mL), compared with only 10% of term controls (odds ratio 3.1, 95% CI 1.1-8.7; P = .03). Elevated matrix metalloproteinase-8 remained associated with preterm premature rupture of membranes after adjustment for maternal age, race, parity, gestational age, and year of amniocentesis (odds ratio 3.4, 95% CI 1.2-9.9; P = .03).
The overall distribution of midtrimester amniotic fluid matrix metalloproteinase-8 levels did not differ between women who had preterm premature rupture of membranes and those delivered at term. However, marked elevations of midtrimester amniotic fluid matrix metalloproteinase-8 were highly associated with subsequent preterm premature rupture of membranes, suggesting that the pathophysiologic processes that contribute to preterm premature rupture of membranes may begin in early pregnancy.
This prospective study was designed to perform lamellar body count of amniotic fluid to evaluate fetal lung maturity. Lamellar body counts of 80 amniotic fluid samples from 80 pregnant women (28-40 weeks of gestation) were evaluated. After delivery, each infant was evaluated for any evidence of respiratory distress syndrome. Standard clinical and radiographic criteria were used to diagnose respiratory distress syndrome, and the diagnosis was confirmed by reviewing newborn records. Twenty (25%) infants delivered within 24 hours of sample collection developed RDS. Lamellar body count more than 50,000/microl predicted pulmonary maturity. Seventeen out of 20 respiratory distress syndrome cases had been predicted correctly. The negative predictive value of lamellar body count>50,000/microl was 93% and positive predictive value was 48% and the sensitivity for prediction of RDS was 85% and specificity was 70%. Lamellar body count can be used as a favourable predictor of fetal lung maturity because it is quick, simple and universally available. Also it can be used as an extremely inexpensive, reliable screening test for evaluating fetal lung maturity.
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Strong TH Jr, Hayes AS, Sawyer AT, et al. Amniotic fluid turbidity: a useful adjunct for assessing fetal pulmonary Ram et al / Role of Echogenic Amniotic Fluid Particles in RDS and lobor Copyrighted © by Dr. Arun Kumar Agnihotri. All right reserved 11 maturity status. Int J Gynaecol Obstet. 1992 Jun;38(2):97-100.
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Amniotic fluid spontaneous labor at term
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Midtrimester amniotic metalloproteinase-8 above the 90th percentile are a marker for subsequent preterm premature rupture of membranes
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Biggio JR Jr, Ramsey PS, Cliver SP, et al. Midtrimester amniotic metalloproteinase-8 above the 90th percentile are a marker for subsequent preterm premature rupture of membranes. Am J Obstet Gynecol. 2005 Jan:192(1):109-13.
Interleukin 1 sebaceous glands
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