Fetal lung maturity

In an interesting medical application, the formation of a stable black foam film from amniotic fluid can be used as an assessment of fetal lung maturity [206]. 

A 22-year-old female carrying a preterm pregnancy (33 weeks) is in labor. Which of the following drugs can be given to the mother to promote fetal lung maturity ... 

A Cochrane metaanalysis shows the benefit of antenatal corticosteroids for fetal lung maturation to prevent respiratory distress syndrome, intraventricular hemorrhage, and death in infants delivered prematurely. 

In children, a leukemoid reaction has been induced by betamethasone treatment (135) this possibility must always be borne in mind, since glucocorticoids can actually be used to treat leukemia or its complications. A case of very high white blood cell count with neutrophilia in a preterm infant whose mother had received two doses of betamethasone prenatally to enhance fetal lung maturation is one of a short list of leukemoid reactions possibly attributable to antenatal glucocorticoid treatment (136). 

In an analysis of 595 preterm infants born at 26-32 weeks gestation during a randomized controlled trial for the prevention of lung disease, glucocorticoids given to women at risk of preterm delivery promoted fetal lung maturation, reduced the incidence of respiratory distress syndrome, and reduced neonatal morbidity and mortality (370). Dexamethasone was given as either two doses of 12 mg 24 hours apart or four doses of 6 mg every 6 hours. Mortality was 9.2% after three or more courses, compared with 4.8% after one or two courses. This association was not explained by other factors (maternal or other common preterm morbidities). 

Prenatal glucocorticoid therapy to enhance fetal lung maturation reduces neonatal morbidity and mortality. However, adverse effects of serial courses of betamethasone on mother and fetus can occur. 

Maternal hyperadrenalism occurred after five courses of betamethasone to enhance fetal lung maturation (374). 

Hyperadrenalism has never otherwise been reported after the sequential use of glucocorticoids for fetal lung maturation. 

Another application to pre- and newborns was published by Liu et al. in 1997 [95]. In this paper, they presented a measure of fetal lung maturity from the spectra of amniotic fluid. The lecithin/spingomyrlin (L/S) ratio was determined by thin layer chromatography (TLC) and used to calibrate a NIR equation using the whole amniotic fluid extracted from pregnant women. About 350 iL of fluid was required. This was scanned from 400 to 2500 nm using a commercially available instrument. The correlation between further samples of fluid and TLC results was about 0.91, considered excellent for the complexity of the solution and extremely small sample size. Of course, a PLS equation was needed due to the complex nature of the samples. 

The technique of amniocentesis is described in Ghapter 2. Additional information can be found in the section on tests for evaluating fetal lung maturity later in this chapter. 

In this section of the chapter, we review methods for measurements of CG, AFP, UE3, DIA, fetal fibronectin, and amniotic fluid bihrubin, and six tests for fetal lung maturity. 

TABLE 54-6 Number of Laboratories Performing Fetal Lung Maturity Testing, by Method College of American... 

Surfactant proteins (SP-A and SP-B) have been evaluated as potential fetal lung maturity tests, but the results are disappointing. ... 

The American College of Obstetricians and Gynecologists issued an educational bulletin on the assessment of fetal lung maturity in 1996. Readers may want to carefully read that bulletin, because many obstetricians rely on it. 

Collection and Handling of Amniotic Fluid for Fetal Lung Maturity Assessment... 

Many laboratories used a commercial version of this test, called Lumadex, FSI Fetal Lung Maturity Test (Beckman Instruments, Fullerton, Calif.), which was introduced in 1982. Beckman Instruments discontinued this test in 1997. The procedure is described on the Evolve site that accompanies this book. 

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