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PubMed1997

Changes in amniotic fluid immunoreactive corticotropin-releasing factor (CRF) and CRF-binding protein levels in pregnant women at term and during labor.

Corticotropin-releasing factor (CRF)-binding protein (CRF-BP) modulates the activity of the hypothalamus-pituitary-adrenal axis during pregnancy, counteracting the actions of circulating or locally produced CRF. The aim of the present study was to evaluate CRF and CRF-BP levels in amniotic fluid of healthy pregnant women during the last 4 weeks of gestation and during spontaneous labor at term. A cross-sectional study was conducted on amniotic fluid collected from pregnant women (n = 68), subdivided into two groups: 1) not in labor (n = 31), and 2) in labor (n = 37). CRF-BP was measurable in all specimens of amniotic fluid, but at 37 weeks of pregnancy the concentration in amniotic fluid was lower (10-fold) than that in maternal plasma (P < 0.01). Pregnant women at 39 and 40 weeks gestation had amniotic fluid CRF-BP levels significantly lower than those at 37 weeks (P < 0.01), and pregnant in women in labor had significantly lower levels than women at term but not in labor (P < 0.01). CRF levels in amniotic fluid and plasma collected in women at 40 weeks gestation not in labor or in labor were significantly higher than those at 37 weeks (P < 0.01). During the last 4 weeks of gestation, amniotic fluid CRF levels in women not in labor did not significantly differ from those obtained at term labor. During the last weeks of pregnancy, amniotic fluid CRF-BP levels decrease and are inversely correlated to CRF levels. The decrease in amniotic fluid CRF-BP at term, augmenting the amount of free CRF, supports the hypothesis that labor is associated with significant changes in local autocrine and paracrine factors that may affect PG release and myometrial contractility, contributing to the mechanism of parturition.

Adult↗
PubMedDate not supplied

[Enzymatic determination of lecithin concentration in the amniotic fluid for antepartal determination of fetal lung maturity].

An enzymatic method of determining the lecithin concentration in the amniotic fluid is compared with the present standard method of antepartal determination of fetal lung maturity, i.e., determination of the lecithin-sphingomyelin (L/S) ratio. A total of 320 amniotic fluid samples, of which 154 were obtained within the 72 hours preceding birth, were studied by both methods. Simultaneously with the rise in the L/S ratio in the amniotic fluid there is a rise in the enzymatically determined lecithin concentration in the last quarter of pregnancy. The critical threshold value for RDS risk of 2 for the L/S ratio corresponds to a threshold value of 5 mg/100 ml amniotic fluid for the enzymatically analyzed lecithin concentration. Established lung maturity can be demonstrated with the same degree of confidence as by using the L/S ratio. The specificity of the both methods is 91%. It is at least as easily possible to predict the likelihood of respiratory distress syndrome by determining the enzymatic lecithin concentration (11 out of 15 cases) as by means of the L/S ratio (9 out of 15). In order to improve the sensitivity (L/S ratio 60%, enzymatic lecithin determination 73%) it would be necessary to perform an additional analysis-e.g., of phosphatidylglycerol-in the amniotic fluid.

Amniocentesis↗
PubMed1993

Alphafetoprotein levels in amniotic fluid from 8 to 18 weeks of pregnancy.

OBJECTIVE: The aim of this study was to ascertain the normal range of amniotic fluid alphafetoprotein (AFP) levels from 8 to 18 weeks of pregnancy. DESIGN: Amniotic fluid samples obtained by amniocentesis were analysed by radioimmunoassay for AFP. From 8 to 12 weeks, fluid was obtained by transvaginal amniocentesis prior to termination of pregnancy. Samples from 13 to 18 weeks were obtained from amniotic fluid specimens submitted for cytogenetic analysis. SETTING: A tertiary referral prenatal diagnostic service. SUBJECTS: Two hundred thirty-seven women between 8 and 18 weeks gestation. RESULTS: High levels of AFP were present in amniotic fluid at 8 weeks (median 83.0 kU/ml), falling rapidly to 11 weeks (median 19.9 kU/ml) (P < 0.01). Levels then rose to a peak at 13 weeks (median 30.7 kU/ml), thereafter falling to 18 weeks. CONCLUSIONS: A single coherent view of the levels of AFP from 8 to 18 weeks of pregnancy is presented for the first time. The rapid changes and complex pattern of AFP levels in early pregnancy suggest that interpretation of amniotic fluid AFP levels in the diagnosis of neural tube defects may be more difficult between 8 and 13 weeks of pregnancy than in the second trimester.

Amniocentesis↗
PubMed2006

[Monitoring of labour and delivery in the presence of meconium stained amniotic fluid by pulse oximetry].

OBJECTIVES: Evidence of meconium-stained amniotic fluid during labor suggests implementation of close monitoring of fetal well-being. DESIGN: Our purpose was to compare fetal oxygen saturation between cases with normal and meconium stained amniotic fluid. MATERIALS AND METHODS: Fetal oxygen saturation was continuously recorded with use of Nellcor N-400 fetal pulse oximeter in 30 control cases of term labour of normal, and 30 cases of meconium stained amniotic fluid. Distribution of fetal oxygen saturation values during 5 periods of labour was analyzed and compared between the examined groups, and presented in forms of Tables, together with neonatal umbilical artery pH values, Apgar score, birth weight and percentage of caesarian sections performed. RESULTS: No significant differences in fetal oxygen saturation, neonatal umbilical artery pH, birth weight and caesarian sections rate were observed between analyzed groups. Newborns 1-th minute Apgar score (mean value) and base excess was lower in meconium group compared to control group. CONCLUSIONS: Our data demonstrate, that fetal oxygen saturation trends to decrease during labour in fetuses in both groups.

Amniotic Fluid↗
PubMedDate not supplied

Change of adrenomedullin concentrations in plasma and amniotic fluid, and human placental adrenomedullin expression with advancing gestation.

In order to characterize the expression of adrenomedullin during pregnancy, we measured the mature and total concentrations in maternal plasma and amniotic fluid, and examined its expression in fetoplacental tissues. Plasma samples were obtained from 13 normal normotensive non-pregnant women and 14 normal normotensive post partum women. Maternal plasma and amniotic fluid samples were obtained from 37 normal pregnant women (10 in the first trimester, 13 in the second trimester and 14 in the third trimester). Fetoplacental tissues were obtained from first and third-trimester pregnancies. Mature and total adrenomedullin concentrations in plasma and amniotic fluid were determined by using specific radioimmunoassay. The distribution and expression of adrenomedullin were determined using immunohistochemistry, reverse-transcriptase polymerase chain reaction, and in situ hybridization. Plasma total adrenomedullin concentrations were increasing with advancing gestation. The mature/total adrenomedullin ratio in the second trimester was the highest during pregnancy. Mature and total adrenomedullin concentrations in the amniotic fluid were significantly higher than those in the maternal plasma throughout gestation (P< 0.05). Mature adrenomedullin concentrations and the mature/total adrenomedullin ratio in the amniotic fluid increased with advancing gestation. There was a significant linear correlation between amniotic fluid and maternal plasma mature/total adrenomedullin ratio in the first or second trimester of pregnancy. Adrenomedullin mRNA was identified in the amniotic membrane and chorionic villi, and within the endothelial layers of villous blood vessels. These results suggest that the mature/total adrenomedullin ratio is modified in maternal plasma and amniotic fluid with advancing gestation.

Adrenomedullin↗
PubMed1976

Measurement of 3,3',5'-Triiodothyroinine (reverse T3), 3,3'-L-diiodothyronine, T3 and T4 in human amniotic fluid and in cord and maternal serum.

In order to assess fetal function at term, we have investigated parameters of thyroid hormone secretion and degradation in human amniotic fluid and in cord and maternal sera at delivery. The parameters measured included 3,3' L-diiodothyronine (3,3'T2), 3,3',5'-triiodothyronine (reverse T3), 3,3',5'-triiodothyronine (T3), thyroxine (T4), dialyzable T3 and T4, thyroxine binding globulin (TBG),and total iodine. The mean (+/- SE) 3,3'T2 concentrations in cord sera, amniotic fluid, and maternal sera were 20 +/- 1 ng/100 ml, 20 +/- 2 ng/100 ml,and 27 +/- 3 ng/100 ml, respectively. The normal range of this metabolite in the sera of non-pregnant adult subjects was 7 to 29 ng/100 ml. The mean (+/- SE) concentration of reverse T3 was higher in cord sera (315 +/- 16 ng/100 ml), amniotic fluid (82 +/- 25 ng/100 ml) and maternal sera (79 +/- 5 ng/100 ml) than in the sera of normal subjects (mean +/- 2 SD; 60 +/- 12 ng/100 ml). In amniotic fluid, T3, T4, and TBG were low, per cent dialyzable T3 and T4 were increased, and iodine concentrations were relatively normal in comparison to their respective serum levels in euthyroid adults. Since T3 and T4 were low in amniotic fluid our data indicate that measurements of 3,3'T2, reverse T3, or per cent dialyzable T3 and T4 in amniotic fluid would be the potentially most useful in establishing the diagnosis of congenital hypothyroidism before birth. In addition, these studies demonstrate that 3,3'T2 is normally present in the peripheral circulation and suggest that reverse T3 is the major source of 3,3'T2 in both amniotic fluid and cord blood.

Amniotic Fluid↗
PubMed1976

The effect of labour on ACTH and cortisol levels in amniotic fluid and maternal blood.

Levels of adrenocorticotrophic hormone (ACTH) and cortisol were measured in amniotic fluid during labour and in maternal blood during and after labour. There was a significant rise of maternal ACTH and cortisol levels during labour and a significant decrease after delivery in all 14 patients studied. There were no significant changes in amniotic fluid ACTH and cortisol levels during labour. The initial level of ACTH in amniotic fluid (162-7 pg/ml) was higher than that in maternal circulation (120-2 pg/ml). The correlation between maternal and amniotic fluid ACTH was not significant while the corresponding correlation for cortisol values was.

Adrenocorticotropic Hormone↗
PubMed1987

The measurement of amniotic fluid immunoglobulins by laser nephelometry.

Using laser nephelometry IgG, IgA, and IgM levels in amniotic fluid samples from normal pregnancies were measured between 15 and 24 weeks and between 37 and 41 weeks gestation. Not enough samples between 25 and 36 were available for statistical analysis. IgG levels increased until the 20th and 24th weeks of gestation and declined significantly at term. However amniotic fluid IgM and IgA levels rose at term. Five samples of amniotic fluid associated with a fetus of abnormal karyotype were examined. In one case of Down's syndrome excessive IgA and IgM levels were found. In amniotic fluid obtained after intrauterine fetal death at term, very high levels of all three immunoglobulins were found.

Amniotic Fluid↗
PubMed1982

[Fundamental studies of transferred concentration of piperacillin into maternal serum, umbilical cord serum and amniotic fluid].

In order to evaluate the clinical efficacy of piperacillin (PIPC) in the obstetrical field, 1 g of PIPC was intravenously administered to 45 normal term gravidas and PIPC concentrations in maternal serum, umbilical cord serum and amniotic fluid were determined. Fifty-three samples of maternal serum, 45 samples of umbilical cord serum and 44 samples of amniotic fluid were obtained at amniotomy and delivery. The results of these studies are summarized as follows. 1. Mean biological half life of PIPC in maternal serum administered to term gravidas was 61.43 minutes. 2. Placental transfer of PIPC concentration into umbilical cord serum was about 71% of maternal serum concentration after 1 hour. 3. There was no prominent difference in the PIPC concentrations of the amniotic fluid between the ruptured and unruptured cases. Fast transfer of PIPC into the amniotic fluid was recognized, such as 1 case was already raised to 4.3 micrograms/ml of PIPC in the amniotic fluid at 1 hour after administration. 4. The maternal serum and amniotic fluid concentration had a contrary relationship, and crossed each other at ca. 5 micrograms/ml of concentration after 2 hours and 50 minutes. Over a period of 6 hours and 20 minutes, the amniotic fluid concentration gradually increased.

Amniotic Fluid↗
PubMed1975

Bacterial growth inhibition by amniotic fluid. IV. Studies on the nature of bacterial inhibition with the use of plate-count determinations.

Bacterial growth inhibition in amniotic fluid is associated with a compound or class of compounds which resembles antibacterial cationic peptides. The inhibitor studied in amniotic fluid is sensitive to treatment with monobasic and dibasic potassium phosphate, and the inhibitory activity of amniotic fluid is lost following adsorption onto bentomite. The inhibitory component in amniotic fluid interacts with bacterial cells by adsorption or is internalized by viable cells only. The inhibitory quality of amniotic fluid is not destroyed by heating to 100 degrees C. for 15 minutes, and this heat-stable inhibitory activity is associated with the compound or compounds which are phosphate sensitive. A possible mode of antibacterial action which is consistent with the data presented is discussed.

Adsorption↗
PubMed1976

Bacterial growth inhibition by amniotic fluid. VI. Evidence for a zinc-peptide antibacterial system.

The zinc bacterial inhibitory activity of amniotic fluid is dependent on the presence of a second, organic component contained in amniotic fluid. The second component is heat stable, resists proteolytic digestion, and is present in amniotic fluid throughout pregnancy. Further, the component may be a peptide with a molecular weight of less than 5,000 daltons. Phosphate reversal of amniotic fluid inhibitory activity may result from interference with the organic component rather than zinc.

Amniotic Fluid↗
PubMed1995

[Evaluation of the usefulness and reference values for the amniotic fluid index in normal pregnancy between 30 and 42 weeks of gestation].

The four-quadrant sum of amniotic fluid pockets (amniotic fluid index) was studied prospectively in 130 normal pregnancies from 30 to 42 weeks. Statistical investigation were used to establish the mean, 95% confidence intervals and standard deviations for the AFI at each week of gestation. The AFI value decreased since 30 week, especially between 33 and 34 week and after 41 week. The AFI value < or = 5 represents oligohydramnios, the AFI value > or = 20 constitutes polyhydramnios.

Amniotic Fluid↗
PubMed2001

Cytokine levels in midtrimester amniotic fluid in normal pregnancy and in the prediction of pre-eclampsia.

Midtrimester amniotic fluid cytokines may reflect the function of the maternal immune system in the maternal-fetal interface and thus be predictive of pre-eclampsia. We determined the concentrations of interleukin (IL)-6, IL-8, IL-10, IL-11, IL-12, IL-15, tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta in amniotic fluid at 14-16 weeks of gestation from women with normal pregnancies and from those who subsequently developed severe pre-eclampsia. The concentrations of the cytokines in amniotic fluid did not significantly differ between patients and normal controls. The median concentration of IL-6 was 950 pg/ml in normal pregnant women and 578 pg/ml in the patient group. The median concentration of IL-8 was 606 pg/ml in normal controls and 294 pg/ml in the patient group. The levels of IL-6, IL-8 and TGF-beta correlated positively with each other. TNF-alpha concentrations were low and similar in both groups. IL-10 and IL-12 were detected at very low levels in 37 and 7% of the samples, respectively. No difference was found in IL-15 concentrations between the groups. IL-11 was found only at low levels in both groups. Although none of the cytokines measured was predictive of pre-eclampsia, this study provides information of cytokines in amniotic fluid during the period when the spiral arteries are remodelled.

Adult↗
PubMed1987

Differential regulation of prostaglandin production by inhibitors and stimulators in amniotic fluids during normal and dysfunctional labor.

The regulatory effect of amniotic fluid factors on prostaglandin production by sheep seminal vesicle prostaglandin synthetase was determined using samples obtained before and after the onset of labor. Variations in the enzyme incubation conditions permitted the effects on both prostaglandin E (PGE) and prostaglandin F (PGF) production to be assessed. Amniotic fluid obtained before the onset of labor and during early labor resulted in a net stimulation of PGE production and no difference was observed between these two groups. Samples obtained before and during early labor had no net effect on PGF production. However, when samples obtained late in labor were tested, there was a greater stimulation of PGF and less of PGE compared to early labor suggesting a preference for PGF production rather than PGE in late labor. When samples obtained from patients in dysfunctional labor were compared to normal labor, no difference on the effect of either PGE or PGF production was observed. This implies that the decreased PGF previously described in dysfunctional labor is due to an intrinsic abnormality of the fetal membranes rather than inhibition of prostaglandin production by factors mediated via the amniotic fluid.

Amniotic Fluid↗
PubMed1978

Total protein patterns in human amniotic fluid.

Total protein patterns of amniotic fluid samples of different age groups, following polyacrylamide disc gel electrophoresis, showed a wide range of variation in early pregnancy, but no two cases had identical banding, indenticating their genetic variability. An assessment has been made here of the total protein, albumin and transferrin patterns from normal fluids of different age groups by gel electrophoresis, in order to observe the genetic variations and relationship with foetal age, if any.

Albumins↗
PubMed1988

Neutral-red uptake and expression of monocytic antigens in amniotic-fluid mononuclear phagocytes: evaluation of a novel approach for prenatal diagnosis of neural-tube defects.

In cases of fetal neural-tube defects macrophages are present in the amniotic fluid. We found that these viable phagocytic cells take up neutral-red and are easily identified as "red cells" by microscopic examination. This method is suitable for the rapid identification and counting of amniotic-fluid macrophages in suspension. We have studied 298 amniotic fluid samples. In the 226 normal cases studied, 0 to 1,200 macrophages per milliliter amniotic fluid have been found. In contrast, we found 1,250 to 99,000 macrophages per milliliter amniotic fluid in our 70 open neural tube defect (ONTD) cases. Statistical evaluation was performed to estimate the normal and pathologic ranges. Specificity and sensitivity of the neutral-red test and predictive value of positive and negative results have been calculated and presented in comparison with alpha-fetoprotein (AFP) determinations and ultrasonic methods. In 5 cases of anencephaly and 7 normal cases amniotic fluid cells were studied by immunocytochemistry: mononuclear cells present in the abnormal cases showed intense immunoreactivity for the Mo1 and Mo2 surface antigens of the phagocytic cell lineage.

Amniotic Fluid↗
PubMed1976

Amniotic fluid alpha-fetoprotein as a marker in prenatal diagnosis of neural tube defects.

The prenatal diagnosis of anencephaly and spina bifida (neural tube defect, NTD) through amniotic fluid analysis for alpha-fetoprotein (AFP) is gradually gaining clinical recognition. AFP concentrations were determined in 237 amniotic fluids from normal pregnancies ranging between 7 and 42 weeks of gestation. A steady decline in AFP from 26 mug/ml at 7-9 weeks to 155 ng/ml at term is observed. AFP concentration was determined in 35 amniotic fluids from 33 confirmed neural tube defective pregnancies. In 14 cases where amniotic fluid was examined prior to the 26th week of gestation. AFP was markedly elevated when compared with the normal range of the same gestational period. In 21 amniotic fluids past the 26th week, 17 cases (85-) had markedly elevated AFP levels; however, 2 cases of anencephaly, 1 of spina bifida, and 1 of hydrocephaly gave levels within the normal range. It is concluded that elevated AFP in the amniotic fluid is a reliable but nonspecific marker for open neural tube defects prior to the 26th week of pregnancy, but may become normal after the 26th week in a small percentage of patients.

Amniotic Fluid↗
PubMed2006

Protein C, protein S, and thrombomodulin in amniotic fluid. A preliminary study.

OBJECTIVES: The main components of protein C anticoagulant system are protein C (PC), protein S (PS) and thrombomodulin (TM); the system plays a protective role in pregnancy, mainly because it prevents the utero-placental circulation from local thrombosis. It is unknown whether the protein C anticoagulant pathway exists in amniotic fluid. The aim of the present study is to find out whether these three components are present in amniotic fluid. STUDY DESIGN: The study group consisted of 50 parturients with an uneventful pregnancy and birth and 25 non-pregnant controls. Amniotic fluid and blood were sampled at the end of the 1st stage of labor. PC, PS and TM were measured by immunoenzymatic method. RESULTS: All the samples of amniotic fluid contained measurable amounts of antigens of PC, PS and TM, although their concentrations were significantly lower than in the mother's blood: (i) The concentration of PC in amniotic fluid was 6.24+/-3.50% and PS 2.40+/-1.64%, while in the mothers' plasma it was 138.26+/-12.38% and 93.15+/-13.24%, respectively (P<0.0001). (ii) TM concentration in amniotic fluid constituted 63.92% of the concentration in the mother's blood (2.71+/-1.21 ng/mL vs. 4.24+/-0.88 ng/mL, P<0.001). CONCLUSION: Protein C, protein S and thrombomodulin are physiological constituents of the amniotic fluid. As their concentrations are low, it is reasonable to assume that they cannot counterbalance the procoagulant activity of amniotic fluid.

Adult↗