TITLE:
Noninvasive Fetal Lung Maturity Prediction Based on Amniotic Fluid Turbidity Using Ultrasonic Histogram Measurement Function
AUTHORS:
Kensuke Matsumoto, Kaoru Yamawaki, Kazufumi Haino, Koji Nishijima
KEYWORDS:
Amniotic Fluid, Brightness, Fetal Lung, Histogram, Turbidity
JOURNAL NAME:
Open Journal of Obstetrics and Gynecology,
Vol.13 No.1,
January
18,
2023
ABSTRACT: Background: Amniotic fluid turbidity increases with fetal lung maturation due to
vernix and lung surfactant micelles suspended in the amniotic fluid. This study
focused on this phenomenon and evaluated the presence or absence of respiratory
distress syndrome (RDS)/transient tachypnea of the newborn (TTN) by
quantitatively assessing the brightness of the amniotic fluid turbidity using a
noninvasive ultrasound histogram measurement function. Methods: We
included cases of singleton pregnancies managed at the Niigata University
Medical and Dental Hospital between November 2020 and March 2022. Histograms of
amniotic fluid turbidity were measured at the center of the amniotic fluid
depth, avoiding the fetus, placenta, and umbilical cord, with the gain setting
set to 0, and the average value was obtained after three measurements.
Histograms of fetal urine in the bladder were measured similarly. The value
obtained by subtracting the fetal bladder brightness value from the amniotic
brightness value based on histogram measurements was used as the final amniotic
fluid brightness value. Results: We included 118 cases (16 of RDS/TTN
and 102 of control). The gestational age of delivery weeks was correlated with
amniotic fluid brightness (Spearman’s rank correlation coefficient was 0.344; p
= 0.00014). Amniotic fluid brightness values were significantly lower in the
RDS/TTN group than in the control group (RDS/TTN: 16.2 ± 13.5, control: 26.3 ±
16.3; p = 0.020). The optimal cutoff value of amniotic fluid brightness to
predict RDS/TTN was 20.3. For predicting RDS/TTN, the sensitivity, specificity,
positive predictive value, and negative predictive value were 91.7%, 69.6%,
26.2%, and 94.1%, respectively. Conclusions: The quantitative value of
the amniotic fluid brightness by histogram measurements may provide an easy and
objective index for evaluating the presence or absence of RDS/TTN.