Effect of infused hypothalamic phospholipids on the maturation of foetal rabbit lungs

The effect of hypothalamic phospholipids on the maturation of foetal lung was investigated in a series of experiments in rabbits. Sixteen pregnant does were injected with hypothalamic phospholipids (2 mg day-1 kg-1) from day 21 of gestation. A second group of 16 does was injected with saline, and served as controls. The foetuses were delivered at gestational ages between 27 and 28 days by means of caesarean section under intravenous pentothal anaesthesia. Foetuses born from treated mothers were more active, breathed better, and their lungs expanded to a greater extent compared with the foetuses born to control mothers. In the animals of treated mothers there was, on electron microscopy, evidence of accelerated maturation of alveolar epithelial cells.     

Amniotic fluid phospholipids. Study of the cold acetone precipitation effect

Amniotic fluid phospholipids were extracted and separated with chloroform: methanol (2:1 by vol). These phospholipids were also precipitated with cold acetone and the percentage of each phospholipid precipitated was calculated. The precipitation percentage of the six phospholipids studied ranged from 33.78 +/- 0.70 (mean +/- SEM) for lecithin to 93.77 +/- 1.40 for phosphatidylserine. The variation of L/S, PG/S and PI/S ratios depending on the precipitation step was also studied. We observed that cold acetone precipitation decreased L/S and PG/S ratios, whereas PI/S remained unchanged. Our results indicated that: (1) cold acetone precipitation affected each phospholipid in a different way; (2) the precipitation step was not an effective way of completely separating surfactant and non-surfactant material; (3) a new predictive value should be established if the L/S ratio without precipitation is to be used in the clinic on a daily basis.     

Amniotic fluid alkaline ribonuclease activity: an indicator of foetal growth retardation and anencephaly

Amniotic fluid alkaline ribonuclease (RNase) activity was measured in 55 normal and 29 neural tube defect pregnancies. The pregnancies which resulted in neural tube defects gave a mean value of 2,500 U/l with a SD of 600 compared with a mean activity of 1,600 U/l (SD 350) from the control normal pregnancies. The mean amniotic fluid RNase activity of 15 anencephalic pregnancies was 2,600 U/l (SD 600), compared with 1,600 U/l (SD 350), for 28 gestational age-matched controls. Highest RNase activities appear to be related to anencephaly.     

Amniotic fluid embolism

Amniotic fluid embolism is a rare occurrence, with no single pathognomonic clinical or laboratory finding. Diagnosis is based on clinical presentation and supportive laboratory values. We describe the case of a 17-year-old nulliparous woman at 27 weeks' gestation who had uterine bleeding, hematuria, hemoptysis, hypotension, dyspnea, and hypoxemia within 30 minutes of vaginal delivery. Laboratory values revealed diffuse intravascular coagulation. Chest films were consistent with adult respiratory distress syndrome. Pulmonary artery catheterization revealed moderately increased pulmonary capillary wedge pressure. Supportive measures, including oxygenation, fluid resuscitation, and plasma, were administered. Central hemodynamic monitoring and inotropic support were necessary. Our patient recovered uneventfully and 6 weeks later was living an unrestricted life-style.     

Amniotic fluid embolus

Amniotic fluid embolus remains among the most fatal obstetrical emergencies, with an extremely high maternal and fetal death rate. There is no way to predict who is at risk for this often catastrophic malady. Increased awareness by the medical community of the signs and symptoms of AFE may allow us to provide earlier aggressive treatment to these patients. Early recognition and treatment remain the best way to start early aggressive intervention aimed at successful outcomes for both mother and child.     

Amniotic fluid embolism

Amniotic fluid embolism is an almost universally fatal complication of pregnancy. We have presented a case and reviewed the literature concerning this rare but catastrophic problem.     

Amniotic fluid embolism

Amniotic fluid embolism (AFE) (also known as anaphylactoid syndrome of pregnancy)is a catastrophic condition that occurs during pregnancy or shortly after delivery. It is found throughout the world in developed and undeveloped countries and occurs at an incidence of between 1 in 80000 live births. In the United States, AFE occurs in 1 in 20000 to 80000 deliveries.     

Amniotic fluid embolism

Amniotic fluid embolism is a rare syndrome that can have debilitating and lethal consequences. It is a difficult and somewhat intangible diagnosis that warrants a high index of suspicion by physicians. Prompt and aggressive supportive treatment is required to lessen an otherwise dismal outcome, which may include death and permanent disability. This article provides an account of the protean clinical features, pathogenesis, and principles involved in treatment.     

Amniotic fluid palmitic acid concentrations and prediction of fetal lung maturity.

A method for rapid determination of total esterified palmitic acid concentration (TEPAC) in amniotic fluid is described. The correlation coefficient between the TEPAC and the lecithin concentration was 0.93 in 123 samples of amniotic fluid obtained during the last trimester. The respiratory distress syndrome (RDS) occurred in 73% of the cases studied with TEPAC less than mmol/l in predelivery samples. The RDS was not observed with higher concentrations except in cases of maternal diabetes mellitus. The predictive value of total esterified fatty acid studies was confirmed to the concentration of palmitic acid recorded, and no specific fatty acid distributions or ratios were reliable in identifying RDS or estimating gestational age.     

Amniotic fluid embolism.

Amniotic fluid embolism remains an enigmatic and often lethal condition. The pathophysiology is complex, however, from a clinical standpoint. Right or, more commonly, left heart failure is the dominant physiologic aberration. Disseminated intravascular coagulation is often present. The detection of squamous cells in the central circulation of living patients can no longer be considered pathognomonic for this condition.     

Amniotic fluid embolism.

Pulmonary embolism is the leading cause of maternal death in the United States. Amniotic fluid embolism (AFE) represents the least preventable and most lethal of complications with a reported mortality of 86% and an associated fetal demise of 50%. Although it is widely accepted as a clinical entity, AFE is incompletely understood. A combination of clinical presentation, laboratory findings, and exclusion of other pathologies leads to the diagnosis of AFE. The mainstays of treatment are oxygenation, maintenance of cardiac output, and correction of coagulopathy. The prognosis for the patient experiencing AFE remains bleak because it is largely unpredictable and, except for supportive measures, cannot be corrected.     

The assessment of foetal lung maturity by chemical analysis of amniotic fluid

Advances in the understanding of the neonatal respiratory distress syndrome have led to a proliferation of amniotic fluid tests. Measurement of pulmonary surfactant production is the most direct means of assessing pulmonary maturity. Assays of surfactant are subjected to certain pre-analysis sources of variation, such as variability in amniotic fluid volume, sample collection site, centrifugation speed and time, and contamination with blood and/or meconium. Amniotic fluid surfactant assays can be divided into biochemical and functional tests. When properly performed, both approaches yield results that correlate well with clinical findings. However, no single method has achieved the distinction of total reliability and universal applicability. In most tests the value for mature lungs is almost 99% accurate. On the other hand, immature values have very low accuracy. Therefore, it is advisable to perform an additional test or to repeat the determination. The determination of the lecithin/sphingomyelin ratio is characterized by sufficient accuracy for routine analyses. For scientific studies we recommend the use of a capillary gas-chromatographic method allowing an accurate assessment of dipalmitoylphosphatidylcholine, the most important surfactant constituent.