Ontogeny of CA 125 antigen in pregnancy: immunoradiometric determination in amniotic fluid and immunohistochemical localization in fetal membranes

CA 125 antigen was measured in amniotic fluid, maternal blood, cord blood, and fetal urine by a commercially available immunoradiometric assay kit. The amniotic fluid was obtained from 99 normal pregnancies at various gestational ages. The mean antigen levels were 29,676, 3350, and 1680 U/ml in amniotic fluid of the first, second, and third trimesters, respectively. In maternal blood, 12.5% of pregnant women in the first trimester of pregnancy showed elevated levels of CA 125 (65 to 100 U/ml). Late in gestation, CA 125 levels in cord blood and fetal urine were always less than 65 U/ml. Immunohistochemical study of CA 125 in fetal membranes, placenta, and decidua showed the presence of antigen only in the amnion. These results suggest that CA 125 is shed into amniotic fluid directly from the amniotic membrane.     

Correlation between fetal sex and human chorionic gonadotropin in peripheral maternal blood and amniotic fluid in second and third trimester normal pregnancies.

BACKGROUND: To study the correlation between fetal sex and human chorionic gonadotropin (hCG) in maternal blood and amniotic fluid. METHOD AND MATERIAL: One hundred and thirty uncomplicated pregnancies, 82 of whom were at sixteen and 48 at thirty-five weeks of gestation. RESULTS: The hCG levels were significantly higher in maternal serum than in amniotic fluid. At 16 weeks there were no sex-related differences in the hCG levels, either in maternal blood or in amniotic fluid. At 35 weeks the hCG levels in maternal blood were significantly higher in pregnancies with female fetuses than in those carrying male fetuses (p<0.004), while in amniotic fluid the hCG levels tended to be slightly higher in the female group than in the male. In pregnancies with female fetuses the hCG levels in maternal blood were significantly higher at 35 than at 16 weeks (p<0.02), while in pregnancies with male fetuses the levels were highest at 16 weeks. For both sexes the hCG levels in amniotic fluid were significantly higher at 16 than at 35 weeks of pregnancy (p<0.001). Whereas a significant correlation between hCG levels in maternal blood and amniotic fluid was seen at 16 weeks of gestation for both sexes (p<0.01 and R value 0.45 for males and 0.41 for females), no correlation was observed at 35 weeks. CONCLUSION: This study shows a significant correlation between hCG and fetal sex at third trimester of gestation only, possibly caused by a gender factor and a shift in synthesis and/or in metabolism of hCG from the second to the third trimester.     

Evaluation of neutrophile elastase and isoprostane 8epiPGF2alpha concentrations in maternal and umbilical cord blood serum and in amniotic fluid in pregnancies complicated by premature rupture of membranes

OBJECTIVES: To evaluate the total isoprostane 8-epi-PGF2alpha and neutrophil elastase (NE) concentrations in pregnancies complicated by premature rupture of membranes (PROM). MATERIAL AND METHODS: 128 pregnant women were divided into four groups: pregnancies complicated by PROM between 24.-36.(PPBP-N) and between 38 a 41 weeks of gestation (PPBP-D), uncomplicated pregnancies between 24-36 gestation weeks (K1) and pregnancies delivered by cesarean section (before uterine contractions had started) after 38 weeks (K2). The concentrations of NE and isoprostane 8-epi-PGF2alpha were measured in maternal serum, cord blood serum and in the amniotic fluid. RESULTS: The following study revealed higher concentrations of NE in maternal serum and in the amniotic fluid than in the umbilical cord blood in PROM cases, and lower amniotic fluid than maternal serum concentrations in the control groups. Also, the levels of isoprostane differentiated between compartments in particular groups. In both groups complicated with PROM, higher maternal serum and amniotic fluid NE concentrations than in controls were found. There were no differences in isoprostane levels between the groups. CONCLUSIONS: 1. Higher concentrations of NE in maternal blood serum and in the amniotic fluid than in the umbilical cord blood in PROM cases, as well as lower amniotic fluid than maternal serum concentrations in the controls, may be connected with pathogenesis of PROM. 2. Differentiated maternal serum, cord serum and amniotic fluid isoprostane concentrations may suggest various intensity of oxidative stress in particular compartments. 3. Lack of differences in maternal serum, cord serum and amniotic fluid isoprostane concentrations may suggest similar intensity of oxidative stress in cases with PROM and intact membranes.     

Folate and vitamin B12 concentrations in maternal and fetal blood, and amniotic fluid in second trimester pregnancies complicated by neural tube defects.

OBJECTIVE: To investigate maternal and fetal folate and vitamin B12 concentrations in pregnancies affected by neural tube defects (NTD). DESIGN: Measurement of folate and vitamin B12 concentrations in amniotic fluid, fetal blood and maternal blood samples in midgestation. SUBJECTS: 32 women undergoing termination of pregnancy at 14-21 weeks gestation for social reasons (n = 24) or for fetuses with neural tube defects (n = 8). INTERVENTIONS: Fetoscopy before intra-amniotic injection of prostaglandins. RESULTS: In normal pregnancies there was a positive correlation between maternal and fetal serum folate, and the fetal serum and red blood cell folate concentrations were higher than the maternal. There were no differences in amniotic fluid, maternal blood or fetal blood folate concentrations between pregnancies with NTD and normal pregnancies. Although amniotic fluid vitamin B12 was lower in pregnancies with NTD, maternal serum vitamin B12 concentration was not reduced. CONCLUSION: In this small group of pregnancies with NTD at mid-gestation there is no evidence to suggest folate or vitamin B12 deficiency.     

Ontogenetic localization and distribution of S-100beta protein in human placental tissues

OBJECTIVE: To investigate whether S-100beta, a brain-specific protein found in amniotic fluid and fetal circulation, is present in fetoplacental tissues throughout gestation. METHODS: S-100beta protein localization and concentration were assessed in placentae, fetal membranes, and cord vessels. Tissues were obtained from 40 pregnant women at different gestational ages: first trimester (n = 10), second trimester (n = 10), early third trimester (n = 10), and late third trimester (n = 10). RESULTS: In the placenta, S-100beta was localized in villous and intermediate trophoblast cells. The intensity of immunostaining and protein concentration increased with advancing gestation. S-100beta protein was also present in amnion, trophoblast, and decidual cells of fetal membranes, and in endothelial cells of umbilical vessels at all gestational ages. CONCLUSION: This study demonstrated that fetoplacental tissues contain S-100beta protein, suggesting that these tissues may, at least in part, be responsible for the high level found in the fetal circulation. Although the significance of placental S-100beta is unknown, this origin should be taken into account when this protein is used as a marker of brain injury in the fetus or infant at birth.     

Unconjugated and total estriol in human amniotic fluid--changes in the ratios between the two estriol levels with advancing gestational age.

In 172 amniotic fluid samples of the early second and the third trimester from 115 normal pregnancies the concentrations of unconjugated and total estriol were measured by means of radioimmunoassay. The mean concentrations of unconjugated estriol in amniotic fluid rose from 1.22 ng./ml. in the gestational weeks 15-18 to 7.82 ng./ml. in the gestational weeks 37-40, that is 6.4 times the former value. In contrast, the mean concentrations of total estriol in amniotic fluid increased more strongly, namely from 27.51 ng./ml. in the gestational weeks 15-18 to 777.15 ng./ml. in the gestational weeks 37-40, that is 28.3 times the former value. With advancing pregnancy the proportion of unconjugated estriol to total estriol in amniotic fluid fell, obeying a significant correlation, from 4.43% in the gestational weeks 15-18 to 1.01% in the gestational weeks 37-40. The presumable reasons for this are the rising conjugation rate of estriol excreted with fetal urine, concomitant to fetal maturation, and the relative transfer diminution of unconjugated estriol from maternal plasma into amniotic fluid with the advance of gestation.     

Increased inorganic sulfate concentrations in amniotic fluid.

We assayed inorganic sulfate by ion chromatography in 49 amniotic fluid samples from pregnancies of 14 to 38 weeks gestation. In second trimester samples (14 to 26 weeks gestation), amniotic fluid sulfate concentrations (317 +/- 22 mumol/L, mean +/- SE; n = 32) were not different from previously reported maternal serum values but were significantly lower (p < 0.001) than in the third trimester (693 +/- 42 mumol/L; n = 16). In third trimester samples, sulfate concentrations were significantly correlated with creatinine and uric acid but not chloride, suggesting that renal excretion may be the major source of the amniotic fluid sulfate in the late stages of gestation.     

Total Proteins in Human Amniotic Fluid

Summary: The study of the biochemical constituents of amniotic fluid is essential in the diagnosis of fetal disorders which result in high concentrations of metabolites in the fetal serum, that can be detected by amniotic fluid examination. The present study is based on the estimations of total protein concentration in the amniotic fluid of normal pregnancies at different gestational weeks. The total protein concentrations, determined by the method of Lowry et al (1951), revealed a characteristic trend during different gestations, with a progressive rise from the 12th week till the 24th week, and then a gradual decline from the 30th week till the 40th week of gestation. Thus, in the third trimester, the total protein decreased with advancement of pregnancy, indicating an inverse relationship with gestational age.     

Corticotropin-releasing hormone in amniotic fluid during gestation and labor and in relation to fetal lung maturation

Corticotropin-releasing hormone was discovered in the placenta, and its concentration in the maternal plasma was found to increase greatly during the latter half of pregnancy. We studied the concentration of immunoreactive corticotropin-releasing hormone in amniotic fluid in 59 uncomplicated and in 73 complicated pregnancies. The mean (+/- SE) value of corticotropin-releasing hormone in amniotic fluid in uncomplicated pregnancies was significantly higher in the third (24.1 +/- 3.3 pmol/L) than in the second (9.1 +/- 0.7 pmol/L) trimester, but no change was found during labor. In groups matched by gestational age, larger mean values of corticotropin-releasing hormone and cortisol were observed in the group in which the lecithin/sphingomyelin ratio was greater than 2 or the phosphatidylglycerol test was positive than in the group with a lecithin/sphingomyelin ratio less than 2 or a negative phosphatidylglycerol test result. In samples taken at an interval of 1 to 3 weeks, concomitant increases in corticotropin-releasing hormone and cortisol levels were found with the appearance of phosphatidylglycerol. Concentrations of corticotropin-releasing hormone in amniotic fluid were elevated in patients with diabetes and in women with preeclampsia and intrauterine growth retardation. We conclude that the intrauterine release of corticotropin-releasing hormone increases during the last trimester. This may stimulate the fetal pituitary-adrenal axis and promote fetal maturation.     

Influence of postdatism and meconium on fetal erythropoietin.

OBJECTIVE: To determine whether fetal erythropoietin (Epo) concentrations are increased in pregnancies extending beyond 41 weeks' gestation and whether this is influenced by the presence of meconium-stained amniotic fluid. METHODS: Epo concentrations were measured in 116 fetal umbilical cord blood samples from otherwise uncomplicated pregnancies between 37 to 43 weeks' gestation during the period of October 1996 to October 1997. An enzyme-linked immunosorbent assay kit was used to measure Epo. Maternal demographics and birth outcomes including Apgar score, cord blood pH, and base deficit were obtained. Fetuses born between 41 and 43 weeks' gestation (post-term) were compared with matched controls born between 37 and 40 weeks' gestation (term). In addition, both post-term and term fetuses with meconium-stained amniotic fluid were compared with matched controls without meconium. RESULTS: Post-term fetuses without meconium had significantly higher Epo levels compared with term fetuses (mean +/- SEM: 50.6 +/- 6.5 versus 29.5 +/- 3.3 mIU/ml, p = 0.002). When matched for gestational age, fetuses with meconium-stained amniotic fluid had significantly greater Epo concentrations compared with controls without meconium (post-term, 80.7 versus 50.6 mIU/ml; term, 61.4 versus 29.5 mIU/ml; p < 0.05). However, no significant difference in Epo levels was found between post-term fetuses with meconium and term fetuses with meconium (80.7 +/- 15.7 mIU/ml versus 61.4 +/- 12.8 mIU/ml, respectively). Mean cord blood pH and base deficit values for all groups were within normal clinical range. CONCLUSION: Cord blood Epo concentrations were significantly increased in pregnancies extending beyond 41 weeks. Irrespective of gestational age, meconium-stained amniotic fluid was associated with a significant rise in Epo. High Epo levels in these pregnancies imply subacute or chronic fetal hypoxia. Close clinical monitoring of post-term fetuses and those with meconium-stained amniotic fluid is warranted.     

The association of birthweight with maternal and cord serum and amniotic fluid growth hormone and insulin levels, and with neonatal and maternal factors in pregnant women who delivered at term

AIM: To investigate the influence of maternal and cord serum and amniotic fluid growth hormone (GH) and insulin and other neonatal and maternal factors on birthweight. METHODS: A total of 160 pregnant women at 38-42 weeks' gestation were studied. All infants were categorized as small for gestational age (SGA) (n = 50), large for gestational age (LGA) (n = 50) or average for gestational age (AGA) (n = 60). GH and insulin levels were measured in maternal and cord serum and amniotic fluid at birth. RESULTS: GH levels in maternal and cord serum and amniotic fluid showed no differences among the three weight groups (P > 0.05). The cord insulin level was significantly lower in SGA (P < 0.01). The insulin level in venous cord blood correlated with birth and placental weights and neonatal height, whereas maternal serum and amniotic fluid insulin levels, and maternal and cord serum and amniotic fluid GH levels did not show any correlation with birthweight. The cord GH level at birth was correlated with GH levels after 4 postnatal weeks in the SGA group (P < 0.01). In addition, birthweight showed a correlation with prepartum maternal weight, maternal weight gain, maternal height, neonatal length and placental weight in all three weight groups. CONCLUSIONS: Cord GH, maternal serum and amniotic fluid GH and insulin levels did not correlate with birthweight in all three weight groups. The lack of correlation for GH levels in maternal and cord serum and amniotic fluid suggests that these compartments may be non-communicating separate units.     

Amniotic fluid beta-endorphin and beta-lipotropin concentrations during the second and third trimesters

Amniotic fluid beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH) were measured by radioimmunoassay after silicic acid extraction and gel chromatographic separation of the two peptides in uncomplicated second-trimester and term pregnancies, in diabetic patients at term, and in pregnancies complicated by Rh-isoimmunization, premature labor, and intrauterine growth retardation. Furthermore, the lecithin/sphingomyelin (L/S) ratios as well as the dehydroepiandrosterone sulfate (DHEA-S) and cortisol levels were determined in most of the amniotic fluid specimens. Both the mean (+/- SE) beta-EP (65.3 +/- 9.1 fmol/ml) and beta-LPH (150 +/- 15.8 fmol/ml) concentrations were significantly higher in the 20 patients with normal pregnancies of 16 to 21 weeks' duration than those found in 21 patients with uncomplicated term pregnancies of 38 weeks' gestation, averaging 42.6 +/- 6.0 and 80.1 +/- 10.7 fmol/ml, respectively. The mean amniotic fluid beta-EP and beta-LPH concentrations measured in the latter subjects were similar to those observed in 23 diabetic patients with otherwise uncomplicated term pregnancies. The mean amniotic fluid beta-EP and beta-LPH levels found in the limited number of patients with Rh-isoimmunization (N = 9), premature labor (n = 8), and intrauterine growth retardation (n = 5) with pregnancies of 24 to 36, 24 to 36, and 34 to 38 weeks' gestation, respectively, were not significantly different from the mean amniotic fluid beta-EP and beta-LPH concentrations of uncomplicated term pregnancies. In all patients but those with Rh-isoimmunization, beta-EP concentrations exhibited a positive correlation with beta-LPH levels. However, the molar beta-LPH:beta-EP ratio was significantly lower at term than during the early second trimester. Neither beta-EP nor beta-LPH correlated with the amniotic fluid L/S ratio and only beta-LPH exhibited a significant inverse correlation with amniotic fluid DHEA-S. The latter was significantly higher in uncomplicated term than second-trimester pregnancies. These results confirm that immunoassayable beta-EP is present in amniotic fluid and declines toward term. These data demonstrate that immunoassayable beta-LPH is present in amniotic fluid and show a more pronounced decrease toward the end of pregnancy than beta-EP. Neither peptide, at least on account of the amniotic fluid levels, appears to be associated with fetal maturation. The physiologic significance of amniotic fluid beta-EP and beta-LPH and their possible role as markers of fetal response to stress remain to be elucidated.     

Levels of CA130 in maternal sera and amniotic fluid at various gestational ages

We examined the CA130 concentration in the amniotic fluid, maternal sera, amnion, chorion, decidua and placenta. CA130 in the maternal sera showed an initial increase during early pregnancy, remained low from the 15th weeks of pregnancy until delivery, and then increased after term delivery (249u/ml, mean, n = 27) or mid-trimester abortions (844u/ml, n = 22). The CA130, concentration in the amniotic fluid was high in the mid-trimester and remarkably low at term. Among the tissues examined, amnion and decidua contained a relatively high concentration of CA130. Immunohistochemical examination also demonstrated abundant CA130 in the cytosol of amnion and decidua tissues. The pattern of changes in CA130 in amniotic fluid was similar to that in the amnion and decidua tissue. The results suggest that the amnion cells are the source of CA130 in the amniotic fluid and that the high concentration of CA130 in maternal serum after delivery originates in decidua tissue affected by the separation of the placenta.     

孕妇血清羊水和新生儿脐血胃泌素的测定

用放射免疫法测定７５例孕１２－４２周健康孕妇的血清、羊水和２６例新生儿脐血胃泌素的浓度。结果：随孕周的增加羊水和血清胃泌素的浓度不断降低，足月后又明显升高，母血清胃泌素浓度高于羊水，以中期行娠为明显（Ｐ〈０．０５）脐血胃泌素浓度在晚期妊娠时较低，足月后升高接近平血清和羊水水平。提示：胃泌素演变的变化是机体在妊娠期的一种生理性代偿作用，并可能与胎儿消化器官发育成熟和功能完善有关。     

LPS induces translocation of TLR4 in amniotic epithelium

Toll-like receptor 4 (TLR4) mediates lipopolysaccharide (LPS) induced immune responses, which may contribute to preterm labor associated with intraamniotic gram-negative bacterial infections. The study objective was to investigate gestational age and LPS-induced changes in TLR4 subcellular localization within amniotic epithelium, the first line of host defense against intraamniotic bacteria. TLR4 localization in amniotic epithelium was assessed using immunohistochemistry on 24 placentas of different gestational ages: first trimester (n=6), second trimester (n=6), and third trimester (n=12). Immunofluorescence was used to determine TLR4 localization following ex vivo LPS stimulation of amnion from women undergoing cesarean section without labor at term. TLR4 was expressed in the cytoplasm of amniotic epithelium starting at 9weeks with apical polarization by 25weeks gestation. TLR4 localization to the basal membrane was significantly associated with chorioamnionitis (p=0.01). After LPS stimulation, TLR4 was expressed sequentially within the apical membrane, cytoplasm, and finally in the basal cellular compartment. This suggests that TLR4 expression in amniotic epithelium is poised to monitor amniotic fluid for pathogens. TLR4 translocation to the basal membrane may decrease LPS signaling early in an infection, but allow the amniotic epithelium to remain competent to invasive or intracellular bacteria.     

Amniotic fluid norepinephrine concentration as an indicator of fetal sympathetic nervous activity. Effect of pregnancy complications

The concentrations of norepinephrine in amniotic fluid and maternal plasma were measured in 71 third trimester pregnancies, 31 of which were uncomplicated and 40 complicated. The amniotic fluid norepinephrine concentration (mean +/- SD) in cases of hypertension treated with clonidine (0.4 +/- 0.1 ng/ml, n = 12) and in insulin-dependent diabetes (0.5 +/- 0.2 ng/ml, n = 7) was lower, and in renal insufficiency (1.7 +/- 0.8 ng/ml, n = 8) higher than in control subjects (0.7 +/- 0.4 ng/ml, n = 31). In fetal-growth retardation (0.6 +/- 0.2 ng/ml, n = 8) and in latent diabetes (0.7 +/- 0.2 ng/ml, n = 5) the values were similar to those in the control subjects. There was a significant positive correlation between mature lecithin-sphingomyelin (L/S) ratio and norepinephrine concentration. Clonidine-treated hypertension was associated with decreased (0.2 +/- 0.1 ng/ml) and renal insufficiency with increased (0.9 +/- 0.7 ng/ml) maternal plasma norepinephrine concentrations (control group, 0.3 +/- 0.1 ng/ml). The present results indicate that measurement of catecholamines in amniotic fluid can be useful in the evaluation of fetal sympathoadrenal function.     

Total complement activity in maternal sera, amniotic fluids and cord sera in women with premature labor, premature rupture of membranes or chorioamnionitis

Total hemolytic complement activity (CH50) was determined in maternal sera, amniotic fluids or cord sera, or all, from 119 patients with preterm uterine contractions, premature rupture of membranes or chorioamnionitis, or all, at 24 to 40 weeks of gestation. The mean CH50 of maternal sera exceeded the mean CH50 of both amniotic fluids and cord sera. The mean CH50 of amniotic fluids exceeded that of cord sera and increased significantly at 32 weeks. This rise preceded that of the mean CH50 of cord sera, which occurred at a fetal weight of approximately 2,500 grams. The mean CH50 of amniotic fluids varied significantly and inversely with that of cord sera. The levels of CH50 in these three fluids did not distinguish between patients with preterm uterine contractions who delivered prematurely and those who delivered at term. The CH50 in patients with premature rupture of membranes did not differ from a control population of women with uncomplicated pregnancies. The mean CH50 of maternal sera was increased in patients with chorioamnionitis but was not predictive of chorioamnionitis. The mean CH50 of maternal sera was decreased in patients who smoked cigarettes and in patients who received intravenous ritodrine.     

IL-8 concentrations in maternal serum, amniotic fluid and cord blood in relation to different pathogens within the amniotic cavity

OBJECTIVE: The association between elevated interleukin (IL)-8 concentrations in amniotic fluid and preterm delivery is well described. Little consideration has been given to the impact of different groups of microorganisms within the amniotic cavity on IL-8 concentration. METHODS: We collected amniotic fluid, placental tissue and amniotic membranes during preterm cesarean sections for bacterial culture. In addition, we determined IL-8 concentrations in maternal serum, amniotic fluid and cord blood and correlated them with the various intra-amniotic pathogens isolated by bacterial culture. RESULTS: IL-8 concentrations were determined in amniotic fluid in 107 cases, in cord blood in 185 cases and in maternal blood in 158 cases. Women with intra-amniotic Ureaplasma urealyticum infection had significantly higher amniotic fluid concentrations of IL-8 than those without (P< 0.001). In cord blood, we found significantly elevated IL-8 concentrations due to intra-amniotic infection with U. urealyticum (P=0.045) and other pathogens (P=0.04). In maternal sera, we found no significant elevation of maternal IL-8 in any of the groups. CONCLUSION: Intrauterine infection with U. urealyticum seems to play a profound role in the cascade of inflammation and increases IL-8 concentrations in amniotic fluid and cord blood.     

Differential expression of human placental PAPP-A2 over gestation and in preeclampsia

IntroductionPregnancy Associated Plasma Protein A2 (PAPP-A2) is a pregnancy related insulin-like growth factor binding protein-5 (IGFBP-5) protease, known to be elevated in preeclampsia. As the insulin-like growth factors are important in human implantation and placentation, we sought to determine the expression pattern of PAPP-A2 over human gestation in normal and preeclamptic pregnancies to evaluate its role in placental development and the pathogenesis of preeclampsia.MethodsPlacental basal plate and chorionic villi samples, maternal and fetal cord blood sera were obtained from preeclamptic and control pregnancies. Formalin-fixed tissue sections from across gestation were stained for cytokeratin-7, HLA-G, and PAPP-A2. PAPP-A2 immunoblot analysis was also performed on protein lysates and sera.ResultsPAPP-A2 expression is predominately expressed by differentiated trophoblasts and fetal endothelium. Chorionic villi show strong expression in the first trimester, followed by a progressive decrease in the second trimester, which returns in the third trimester. PAPP-A2 expression is not impacted by labor. PAPP-A2 is increased in the basal plate, chorionic villi and maternal sera in preeclampsia compared to controls, but is not detectable in cord blood.DiscussionPAPP-A2 is differentially expressed in different trophoblast populations and shows strong down regulation in the mid second trimester in chorionic villous samples. Both maternal sera and placental tissue from pregnancies complicated by preeclampsia show increased levels of PAPP-A2. PAPP-A2 levels are not altered by labor. Additionally, PAPP-A2 cannot be detected in cord blood demonstrating that the alterations in maternal and placental PAPP-A2 are not recapitulated in the fetal circulation.