Evaluation and Predictive Value of Placental Thickness in Fetal Biometric Assessment and Doppler Indices of the Uterine and Umbilical Arteries.

Abstract

Objective: The placenta plays a critical role in fetal development by facilitating the exchange of oxygen and nutrients from maternal blood while removing carbon dioxide and metabolic waste. It also acts as a protective barrier against infections and maintains pregnancy by producing key hormones. As the first organ to reflect pathological changes during pregnancy, placental evaluation can aid in the early detection of pregnancy complications. The primary objective of this study was to assess the correlation between placental thickness (PT) and fetal biometric parameters during the second-trimester anomaly screening, aiming to facilitate earlier detection of pregnancy outcomes.

Materials and methods: This cross-sectional study included 300 healthy pregnant women with gestational ages between 18 and 22 weeks, determined by last menstrual period or first-trimester ultrasound. Participants underwent routine biometric ultrasound assessments, including biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), estimated fetal weight (EFW), and Doppler evaluations of the umbilical and uterine arteries. PT was measured perpendicularly to the uterine wall at the site of cord insertion. Statistical analyses included descriptive statistics, Pearson correlation coefficients, and independent t-tests, with statistical significance set at p < 0.001.

Results: The mean placental thickness (PT) was 23.45 ± 3.99 mm. Statistically significant (p < 0.001) but weak positive correlations were observed between PT and the following fetal growth parameters: estimated fetal weight (EFW) (r = 0.29), abdominal circumference (AC) (r = 0.33), head circumference (HC) (r = 0.21), biparietal diameter (BPD) (r = 0.27), and femur length (FL) (r = 0.29). Gestational age showed a weak positive correlation with PT (r = 0.32). Correlations between PT and Doppler indices, including the umbilical artery pulsatility index (PI) and uterine artery PI, were trivial (r = -0.16 and r = 0.06, respectively). No significant differences in PT were observed based on fetal gender.

Conclusion: PT demonstrates statistically significant correlations with fetal biometric parameters and gestational age, suggesting its potential utility as a marker for fetal growth and development. However, its association with Doppler indices is trivial, indicating limited utility in vascular assessments. These findings highlight the need for further investigation into PT as a noninvasive marker for prenatal assessment, particularly in larger cohorts and during the third trimester.