Use of Near-Infrared Spectroscopic Analysis of Second Trimester Amniotic Fluid to Assess Preterm Births

Figure 3

Normalized spectral absorbance for term and preterm groups. A solid line represents the term group (≥37 weeks), and the dashed line represents the pre-term group (≤35 weeks). This region of the spectrum consists of the 2nd and 3rd overtone absorption from CH, NH, and OH functional groups. Differing concentrations of proteins, fats, and carbohydrates in the matrix lead to increased or decreased absorbance in the spectral region corresponding to the functional groups. The result is essentially a metabolome fingerprint for preterm and term births using 2nd trimester amniotic fluid.