Amniotic Fluid Lecithin: Sphingomyelin Ratio and Fetal Lung Development

Whitfield, C. R.; Chan, Weng Hoong; Sproule, W. B.; Stewart, A.

doi:10.1136/bmj.2.5805.85

Cited by 69 publications

(15 citation statements)

References 4 publications

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“…A comparison of the L/S ratio determined by procedure I (Material and methods) with an alternative method for assessing fetal lung maturity, based on the isolation of a lamellar body fraction from amniotic fluid (Duck-Chong, 1979), suggests that there is a high incidence of false predictions of lung immaturity (Duck-Chong, Gupta, Storey, and Houghton, unpublished data), a finding supported by clinical data from other laboratories (Bryson et al, 1972;Nakamura et al, 1972;Whitfield et al, 1972;Keniston et al, 1975;Olsen et al, 1975). It is very difficult to assess accurately the proportion of false predictions of immaturity because delivery is usually delayed if an immature L/S ratio is reported.…”

Section: Discussionmentioning

confidence: 60%

Is the L/S Ratio Really a Lecithin/Sphingomyelin Ratio?

Duck-Chong

Brown

1979

Ann Clin Biochem

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SUMMARY Fetal lung maturity is commonly assessed by determining the ratio of lecithin/sphingomyelin in centrifuged amniotic fluid. In a variety of chromatographic systems currently used for the routine determination of the lecithin/sphingomyelin ratio, including the systems recommended in the original procedure, at least one and frequently two additional phospholipids, normally present in amniotic fluid, tend to chromatograph between or overlapping with lecithin and/or sphingomyelin. These phospholipids have been tentatively identified as phosphatidylserine and phosphatidylinositol. The extra phospholipids contribute significantly to the routine lecithin/sphingomyelin ratio with considerable variation between individual cases. Treatment of dried lipid extracts with cold acetone before chromatography, as suggested in the original lecithin/sphingomyelin ratio procedure, does not remove the interfering phospholipids.

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Section: Discussionmentioning

confidence: 60%

Is the L/S Ratio Really a Lecithin/Sphingomyelin Ratio?

Duck-Chong

Brown

1979

Ann Clin Biochem

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“…Most biochemical parameters (e.g. oestrogens, pregnanediol levels and the lecithin to sphingomyelin ratio) vary only gradually with no abrupt changes during the specified period of gestation (19,20,21), however, the maternal serum triglyceride level does peak at the 31st week of gestation and. then falls off fairly rapidly (22).…”

Section: Discussionmentioning

confidence: 99%

The metabolism of nicotine in cigarette smokers during pregnancy

Klein

Gorrod

1978

European Journal of Drug Metabolism and Pharmacokinetics

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The urinary excretion of nicotine and its metabolites, nicotine-l '-N-oxide and cotinine, were determined for 40 pregnant and 30 non-pregnant smokers. The pregnant subjects participated in a longitudinal study over their last trimester in order to describe variations in nicotine metabolism with gestational age. No significant relationship was found between the level of excretion of the nicotine metabolites and infant birthweight for the pregnant smokers; nor was evidence found for the preferential accumulation of cotinine compared to nicotine-l '-N-oxide for pregnant compared to non-pregnant smokers. The longitudinal study demonstrated a significant drop in the nicotine-l '-N-oxide excretion level over the 29th to the 32nd weeks of gestation for all six subjects examined over this period.Tests demonstrated that this decrease in the nicotine-l '-N-oxide level was not due to an unusual decomposition effect in the urine.

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“…They evaluated the Lecithin/Sphingomyelin ratio (L/S) that are glycoproteins consisting the Surfactant. The Lecithin increases the effect of the Surfactant, that is why ratio bigger than 2 is necessary for achieving fetal lung maturity [4][5][6][7]. [8,9].…”

Section: Discussionmentioning

confidence: 99%

Determination of Fetal Maturity Using Signal Transformations of Fetal Thalamus Estimating Fetal Maturity by Ultrasound

Dzikova¹,

Dimitrov²,

Stojceva-Taneva³

et al. 2017

Macedonian Medical Review

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Introduction. The complications associated with preterm birth are still the primary cause of death in children below 5 years of age, leading to nearly 1 million death cases in 2013. We performed our study to examine a new non-invasive method for prediction of fetal maturity. Methods. The study was designed asa prospective observational-interventional clinical study, conducted at the University Clinic for Gynecology and Obstetrics, Medical Faculty, University Ss. Cyril and Methodius Skopje, Republic of Macedonia. Ninety pregnant patients were examined, 48 with preterm birth used as examined cases and 42 women above 37 completed weeks of gestation and delivered at term, used as control cases. The investigation was performed before and 72 hours after administration of the therapy protocol for fetal lung maturation. The measurement was done with an ultrasound histogram software, measuring the density of thalamus and surrounding brain tissue. The results were followed up to 72 hours and then compared with the postpartum respiratory distress syndrome (RDS). If the patient was not delivered within 72 hours of measurement, she was excluded from the study. Results. In the first and in the second gestational age group, we noticed significant fetal maturation. All groups according to nationality and religionshowed high significance before and after treatment. The correlation among the thalamus density vs. surrounding brain tissue and postpartum RDS in all three groups according to gestational age, nationality and religion was high. Conclusion. Measuring the density of fetal thalamus vs. surrounding brain tissue may become the new noninvasive technique for determination of fetal maturity.

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Amniotic Fluid Lecithin: Sphingomyelin Ratio and Fetal Lung Development

Cited by 69 publications

References 4 publications

Is the L/S Ratio Really a Lecithin/Sphingomyelin Ratio?

Is the L/S Ratio Really a Lecithin/Sphingomyelin Ratio?

The metabolism of nicotine in cigarette smokers during pregnancy

Determination of Fetal Maturity Using Signal Transformations of Fetal Thalamus Estimating Fetal Maturity by Ultrasound

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