Amniotic fluid microviscosity determined by fluorescence polarization: methodology and relation to gestational age

Area of Science:

• Biochemistry
• Obstetrics
• Neonatology

Background:

• Amniotic fluid composition changes during pregnancy.
• Assessing fetal lung maturity is crucial for managing high-risk pregnancies.

Purpose of the Study:

• To evaluate amniotic fluid microviscosity as an indicator of fetal lung maturation.
• To determine the relationship between microviscosity and the lecithin-to-sphingomyelin ratio and fatty acid saturation.

Main Methods:

• Fluorescence polarization was used to measure microviscosity in 116 amniotic fluid specimens.
• Reproducibility was confirmed (coefficient of variation, 2.0%).
• The impact of bilirubin concentration and dilution was assessed.

Main Results:

• Amniotic fluid microviscosity decreases significantly between 28 and 36 weeks of gestation.
• Measurements correlated with lecithin-to-sphingomyelin ratio and fatty acid saturation.
• Microviscosity changes paralleled the development of the fetal surfactant system.

Conclusions:

• Amniotic fluid microviscosity is a reliable indicator of fetal lung maturation.
• This measurement reflects biochemical properties of amniotic fluid lipids.
• It offers a reproducible and robust method for assessing fetal lung development.