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PubMed1990

Corticotropin-releasing factor and parturition: plasma and amniotic fluid levels and placental binding sites.

We evaluated levels of corticotropin-releasing factor in the plasma and amniotic fluid of women who had spontaneous vaginal delivery or elective cesarean. Corticotropin-releasing factor binding sites were also studied in placental tissue collected from vaginal or cesarean birth. Plasma samples were collected hourly from seven women from the onset of labor until delivery, and from ten women before and during elective cesarean. Amniotic fluid samples were collected from 40 women at different stages of labor and from ten women during elective cesarean. Maternal plasma corticotropin-releasing factor levels increased during labor, showing the highest values at delivery. No significant differences in amniotic fluid immunoreactive corticotropin-releasing factor levels were observed at the different stages of cervical dilatation. At cesarean, maternal plasma levels did not differ significantly from those found before surgery, and in the amniotic fluid they were similar to those found in pregnancy. The number of 125I-corticotropin-releasing factor binding sites in placental tissue was higher after vaginal than after cesarean delivery. These results suggest that corticotropin-releasing factor secretion is activated by the stress of labor.

Adult↗
PubMed1984

Predominance of L-dopa in fetal plasma and the amniotic fluid during late gestation in the rat.

The purpose of this study was to reevaluate catecholamine distribution in fetal and maternal compartments during late gestation in the rat. Fetal and maternal plasma and amniotic fluid were collected from anesthetized rats on consecutive days from day 17 to day 22, the day of parturition. The fluid was analyzed for dihydroxyphenylalanine (L-dopa), dopamine, norepinephrine, and epinephrine by radioenzymatic assays. Amniotic fluid volume was determined by a direct weighing method. L-Dopa concentrations constituted approximately 50% of total fetal plasma catecholamines and were significantly higher in fetal than in maternal circulation. Dopamine concentrations in fetal plasma were tenfold lower than those of L-dopa but were also significantly higher in fetal than in maternal plasma; norepinephrine levels were similar in both. Maternal plasma epinephrine levels remained relatively constant, whereas fetal epinephrine levels increased fiftyfold from day 17 to day 22. L-Dopa concentrations in the amniotic fluid were tenfold higher than those of dopamine, and the concentrations of both increased markedly during the last 2 days of gestation. However, this apparent rise could be attributed to the concomitant fivefold reduction in the amniotic fluid volume observed at this time. It is concluded that L-dopa is the predominant catecholamine in both the fetal plasma and the amniotic fluid during late gestation in the rat. At the present time, neither the source nor the possible physiologic functions of L-dopa during fetal life are known.

Amniotic Fluid↗
PubMed1977

Isoelectric focusing pattern of acid hydrolases in cultured fibroblasts, leucocytes and cell-free amniotic fluid.

The activities of 9 acid hydrolases were determined in cell-free amniotic fluid, leucocytes and cultured fibroblasts using fluorogenic substrates. The specific activities of beta-glucosidase, alpha-fucosidase, beta-hexosaminidase, and arylsulphatase A and B were found to be in the same range in cell-free amniotic fluid and in leucocyties. The isoenzyme pattern of these 5 hydrolases as well as that of acid phosphatase and alpha-mannosidase showed some similarities in all three specimens studied; the pattern of alpha- and beta-galactosidase obtained by isoelectric focusing was different in the 2 types of cells studied and in the cell-free amniotic fluid.

Acid Phosphatase↗
PubMed1987

Effect of albumin and lamellar bodies on fluorescence polarization of amniotic fluid.

Using a probe and procedure developed for the Abbott TDx analyzer, we investigated the influence of albumin on fluorescence polarization of amniotic fluid. Polarization readings increased when albumin was added to either "mature" or "immature" amniotic fluids. Albumin added to a fraction rich in lamellar bodies (10,000 X g pellet) greatly increased polarization readings, but albumin added to the lamellar-body-free fraction resulted in only small increases. Adding increasing amounts of the lamellar-body-rich fraction from mature and immature pools to a constant amount of albumin decreased the polarization readings. We saw no correlation between amniotic fluid polarization and albumin concentration but found a significant correlation between polarization values and either total extractable phospholipids (r = 0.725, P less than 0.001) or the ratio albumin/total extractable phospholipids (r = 0.784, P less than 0.001). The concentration of albumin in amniotic fluid was variable and correlated poorly with gestational age.

Albumins↗
PubMed1998

Can a single measurement of amniotic fluid delta optical density be safely used in the clinical management of Rhesus-alloimmunized pregnancies before 27 weeks' gestation?

BACKGROUND: To assess the efficacy of a single measurement of amniotic fluid optical density deviation at 450 nanometers in predicting fetal anemia in Rhesus-alloimmunization before 27 weeks gestation. METHODS: In this cross-sectional study, fetal blood and amniotic fluid samples from 43 Rhesus-alloimmunized pregnancies at 18 to 26 weeks gestation were obtained under ultrasound guidance. Amniotic fluid samples were scanned by spectrophotometry for optic density at various wavelengths. Deviation at 450 nanometers was calculated between 550 and 365 nanometers. The fetuses were divided into three groups based on their hematocrit levels and the predictive efficacy of optic density zones for anemia was evaluated. RESULTS: A high number of false positive and false negative results were observed when the delta-amniotic fluid optical density of fetuses at risk for anemia was plotted to the zones recently proposed to manage Rhesus-alloimmunized pregnancies. CONCLUSIONS: These data confirm previous results that the diagnosis of fetal anemia in Rhesus-alloimmunized pregnancies before 27 weeks' gestation cannot be accurately made by a single measurement of amniotic fluid optical density at 450 nanometers.

Amniocentesis↗
PubMed1992

Methamphetamine detection from meconium and amniotic fluid in guinea pigs depends on gestational age and metabolism.

Significant adverse perinatal effects of maternal methamphetamine use have been reported, but little is known about factors influencing methamphetamine screening test results during the perinatal period. We tested the hypothesis that gestational age would affect quantitative recovery of methamphetamine in meconium and amniotic fluid. Time-bred guinea pigs received an intraperitoneal (i.p.) injection of 1 mg/kg methamphetamine at either 44 days (0.65 of term, n = 5), 50 days (0.74, n = 8), 56 days (0.82, n = 9) or 63 days (0.93, n = 4) gestation. At 1 or 7 days after i.p. methamphetamine, meconium and amniotic fluid were collected for quantitative methamphetamine assay by gas chromatography-mass spectrometry. Recovery from amniotic fluid and meconium 1 day after injection was influenced by gestational age. Greater values in amniotic fluid and meconium and a higher percentage of positive samples were seen in older fetuses. Collectively at all gestational ages, combined testing of amniotic fluid and meconium yielded detectable methamphetamine or its metabolites in 87% of guinea pigs 1 day after injection. However, methamphetamine was not detectable 1 week after injection in any sample (n = 63) at either 0.74 or 0.82 of term except for one positive amniotic fluid sample. Finally, demethylation of methamphetamine to amphetamine was higher in older fetuses.(ABSTRACT TRUNCATED AT 250 WORDS)

Amniotic Fluid↗
PubMed1990

Factors which affect growth of amniotic fluid cells.

In a study on various factors which are known to influence the growth of amniotic fluid cells for successful cytogenetic analysis in 89 samples, amniotic fluid volume greater than 10 ml enhanced the chance of success (P = 0.0003). The presence of red blood cells reduced the success rate although this was not statistically significant. Among the techniques which proved successful were the use of closed culture method (plastic flasks in which 5% CO2 is blown), and the addition of Ultroser G, which enhances the adhesion and growth of amniotic fluid cells.

Amniotic Fluid↗
PubMed1995

Analysis of dipalmitoyl phosphatidylcholine in amniotic fluid by enzymatic hydrolysis and high-performance thin-layer chromatography reflectance spectrodensitometry.

A novel test for the determination of dipalmitoyl phosphatidylcholine (DPPC) in amniotic fluid (AF) as free dipalmitoylglycerol (DPG), is described. Aliquots of amniotic fluid were hydrolyzed with Bacilus cereus phospholipase C, and the resulting diglycerides analyzed by AgNO3-modified high-performance thin-layer chromatography (HPTLC)-reflectance spectrodensitometry. This HPTLC system provided resolution of DPG and palmitoylpalmitoleoylglycerol (POG) from other 1,2-diglycerides and cholesterol. The turn-around analysis time for triplicate aliquots of amniotic fluid was 40 min. Recoveries ranged between 90 and 98%. In summary, this method provides a quantitative, specific, highly reproducible, and fast turn-around means of analysis of DPPC in amniotic fluid.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1988

Neurone specific enolase in amniotic fluid: a potential marker of anencephaly.

Normal values for neurone specific enolase in amniotic fluid have been found to follow a non gaussian distribution with a 1-99 centile range of 1.10-4.32 micrograms/L. Neurone specific enolase levels have been shown to be raised in the amniotic fluid of pregnancies complicated by anencephaly, although not those complicated by open spina bifida. Neurone specific enolase measured by radioimmunoassay is capable of totally discriminating between normal pregnancies and those complicated by anencephaly. The study demonstrates the possible value of investigating other neuronal proteins which may find value as adjuncts to amniotic fluid Alpha fetoprotein levels in the prenatal diagnosis of Neural Tube Defects.

Amniotic Fluid↗
PubMed1986

Androgen and estradiol levels in plasma and amniotic fluid of late gestational male and female hamsters: uterine position effects.

Using radioimmunoassay we have measured the plasma and amniotic fluid levels of androgen and estradiol in male and female hamster fetuses nearing parturition. On Days 14 and 15 of gestation (day of birth = Day 16), plasma levels of androgen are higher in males than females while estradiol levels are equal. Amniotic fluid levels of these hormones, while lower than plasma, reflect the difference in androgen and the similarity in estradiol between sexes. Uterine position analysis on Day 14 suggests that female siblings located caudally suppress amniotic fluid androgen and elevate estradiol levels of male siblings. Comparison of Day 18 gestation male and female rat amniotic fluid androgen to Day 14 hamsters reveals that male rats are bathed in high levels of androgen. Female rats have lower levels which are not different from those of male hamsters. Female hamsters are exposed to little androgen. Relevance to behavioral sexual differentiation and the display of adult behavior is discussed.

Amniotic Fluid↗
PubMed1998

Ultrasonically dense amniotic fluid in early pregnancy in asymptomatic women without vaginal bleeding. A report of two cases.

BACKGROUND: 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. CASES: 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. CONCLUSION: 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.

Adult↗
PubMed1984

Amniotic fluid and midtrimester amniocentesis: a review.

The potential risks of midtrimester amniocentesis resulting from the loss of amniotic fluid are reviewed. Amniotic fluid fulfils important functions in fetal well-being, but its replacement time after amniocentesis is not known. A review of experimental amniocentesis in animals suggests risks to limbs and structural changes in fetal lungs. In humans, orthopaedic abnormalities and respiratory difficulties appear to be a risk of amniocentesis, and studies addressing these risks are also reviewed. Continued investigation of risks from fluid loss at midtrimester amniocentesis is recommended.

Adult↗
PubMed1979

Renin activity and concentrations of angiotensin I and II in amniotic fluid of normal and Rh-sensitized pregnancies.

Renin activity and the concentrations of angiotensin I and angiotensin II in amniotic fluid of second- and third-trimester pregnancies were determined by radioimmunoassay. Between the 28th and 38th wk of gestation, the mean renin activity in the amniotic fluid was higher than during early pregnancy (before the 18th wk of gestation). Both renin activity and the concentrations of angiotensin I and II were increased on some cases of Rh-incompatibility. One to two weeks after the administration of betamethasone to the mother with threatened premature delivery, the intra-amniotic renin--angiotensin system was slightly suppressed. In urine samples of newborns, angiotensin concentrations were in the same range as those found in the amniotic fluid; renin activity was very low or undetectable in the urine of male neonates (1--7 days of age). Thus, angiotensin II in the amniotic fluid may be derived both from fetal urine and/or as the product of enzymatic reactions in the amniotic sac; the latter is dependent not only on the presence of renin and converting enzyme but also on the local renin substrate (angiotensinogen) concentration.

Adult↗
PubMed1981

Normal fetal growth despite persistent amniotic fluid leakage after genetic amniocentesis.

Two women not only lost relatively large amounts of amniotic fluid immediately following genetic amniocentesis, but continued to lose fluid for the remainder of their pregnancies. Periodic ultrasonographic assessment confirmed normal fetal growth and presence of some amniotic fluid. Both women were delivered at term of normal offspring who showed no evidence of fetal deformations. Although amnionitis is a risk, cautious surveillance may permit continuation of pregnancies complicated by copious or persistent amniotic fluid leakage following genetic amniocentesis.

Amniocentesis↗
PubMed1998

Rapid determination of fetal lung maturity from infrared spectra of amniotic fluid.

OBJECTIVE: The purpose of this study was to determine the feasibility of infrared spectroscopy as an alternative method for the prediction of fetal lung development. STUDY DESIGN: Samples of amniotic fluid were obtained by amniocentesis from 134 patients between the 26th and 41st week of pregnancy. To acquire infrared spectra with a commercial spectrometer, 35 microl of amniotic fluid was required for each spectrum. The lecithin/sphingomyelin ratio was determined separately by thin-layer chromatography for each sample. A robust linear discriminant analysis method was used to partition the samples into normal and abnormal groups according to their infrared spectra. A partial least squares regression analysis was then applied to quantitatively correlate the infrared spectra with the thin-layer chromatography-based lecithin/sphingomyelin ratios. RESULTS: Qualitatively, the infrared spectra of the amniotic fluid in the validation set were successfully partitioned into lecithin/sphingomyelin <2 and lecithin/sphingomyelin >2 groups. Quantitatively, the lecithin/sphingomyelin ratios predicted from the infrared spectra of amniotic fluid were highly correlated and in excellent agreement with those determined by thin-layer chromatography (correlation coefficient = 0.893). CONCLUSION: Infrared spectroscopy has the potential to become the clinical method of choice for determining fetal lung surfactant maturity in amniotic fluid.

Amniocentesis↗
PubMedDate not supplied

Biochemical composition of amniotic fluid in pregnancies complicated with twin-twin transfusion syndrome.

OBJECTIVE: To compare the electrolyte composition of pregnancies complicated with twin-twin transfusion syndrome (TTTS) with that of physiologic pregnancies. MATERIALS AND METHODS: Amniotic fluid samples from 16 pregnancies were studied. Specimens were obtained from recipient sacs in 10 pregnancies undergoing fetoscopy for severe midtrimester TTTS. Additionally, 6 amniotic fluid samples were obtained transcervically from legal second-trimester pregnancy terminations. The concentrations of sodium, potassium, chloride, bicarbonate, calcium, glucose, osmolality, pH, total protein content and albumin were determined in each sample. RESULTS: The mean gestational age at sampling was 20.2 weeks (range 17.2-27.1) in the TTTS group and 18.4 (range 16.0-22.0) in the control group (p = NS). We found significant lower levels of albumin (0.22 +/- 0.04 vs. 0.39 +/- 0.11, p = 0.01) and total protein (0.19 +/- 0.08 vs. 0.51 +/- 0.17, p < 0.001) and higher levels of bicarbonate (16.90 +/- 1.45 vs. 14.50 +/- 2.17, p = 0.02) in amniotic fluid samples taken from recipient sacs of TTTS pregnancies. CONCLUSION: Amniotic fluid from the receptor in severe midtrimester TTTS differs significantly from control amniotic fluid samples in bicarbonate concentration, total protein content and albumin concentration. These findings may help to understand the pathophysiology of TTTS and to optimise therapeutic modalities.

Albumins↗
PubMed1991

Does amniotic fluid index affect the accuracy of estimated fetal weight in preterm premature rupture of membranes?

Estimated fetal weights play a critical role in the management scheme of patients with preterm premature rupture of membranes but are often technically difficult to obtain in these patients because of low amniotic fluid volume. Previous studies have had conflicting data as to the accuracy of estimated fetal weights in preterm premature rupture of membranes. This study was undertaken to evaluate the effect of amniotic fluid index on the accuracy of estimated fetal weights in pregnancies complicated by preterm premature rupture of membranes. Over a 2-year period at Long Beach Memorial Medical Center, 98 patients with preterm premature rupture of membranes who had an ultrasonographic examination with estimated fetal weights and amniotic fluid index performed within 48 hours of delivery were identified and compared with a control group of 55 patients in preterm labor with normal amniotic fluid index for gestational age, also obtained within 48 hours of delivery. Shepard and Hadlock formulas were used to estimate fetal weight. Results were measured in percent error from the actual birth weight. All birth weights were less than 2000 gm. No statistical differences were identified. The value of amniotic fluid index did not affect the accuracy of predicted estimated fetal weight in preterm premature rupture of membranes. Predicted estimated fetal weight of patients with preterm premature rupture of membranes appears to be as accurate as predicted estimated fetal weight in pregnancies with normal amniotic fluid volumes.

Amniotic Fluid↗
PubMed1978

[Influence of an active attitude towards induction of labour, on the occurrence of pathological amniotic fluid - a comparison of the birth years 1967 and 1976 (author's transl)].

An analysis was made of discolored amniotic fluid when our attitude changed towards artificial birth induction. Whereas during 1967 only 8.2% of all births were induced, the total birth inductions during the second comparable year increased to 23.5%. This active interference at the end of the gestation period made it possible to reduce the occurrence of discolored amniotic fluid cases from 13.6% to 6.4%. It was thereby established that the lowered perinatal mortality was partially due to this very significantly reduced occurrence of discolored amniotic fluid. The increased surgical termination of pregnancy, in this group lowered the infant mortality from 2,1% to 0,9%. Based on our observations we feel that in a secured gestation period close to the end of term, active obestrical interference is indicated and in cases of discolored amniotic fluid immediate assistance in terminating the pregnancy is required.

Amniotic Fluid↗