# Placental Thickness Correlates with Severity-Weighted Fetal Dysfunction in the Third Trimester

## TL;DR

Thicker placentas in the third trimester are linked to more severe fetal health issues, especially non-heart-related and heart function problems.

## Contribution

This study introduces a severity-weighted scoring system to show placental thickness correlates with cumulative fetal dysfunction.

## Key findings

- Placental thickness over 70 mm correlates with higher extracardiac dysfunction scores.
- Thick placentas are associated with increased fetal distress indicators like abnormal blood flow.
- Measurement of placental thickness could serve as an early marker of fetal jeopardy in the third trimester.

## Abstract

This research uncovered that embryos presenting augmented placental thickness, especially those surpassing 70 mm, exhibited heightened incidences of both operational cardiac and extracardiac complications. By attributing weights to each diagnosis in accordance with clinical severity, we established that placental thickness is associated with the cumulative burden of fetal dysfunctions. Although a correlation between thick placentae and structural cardiac anomalies was not strongly established, such placentae were more frequently linked to indicators of fetal distress, including atypical blood flow, regurgitation, or soft tissue abnormalities. Measurement of placental thickness is a straightforward process during standard ultrasound examinations and may function as an early marker of fetal jeopardy, especially during the third trimester.

Background: Placental thickness has been associated with adverse perinatal outcomes, but the relationship to specific fetal abnormalities seems to not yet be well understood. This study investigates whether increased placental thickness correlates with the severity of fetal cardiac and extracardiac conditions using a structured classification and severity-weighted scoring system. Methods: We undertook a retrospective analysis of 1452 fetal echocardiograms conducted during the third trimester at a tertiary referral institution from the years 2022 to 2025. The diagnoses were categorized into four distinct classifications: congenital heart anomalies, cardiac dysfunctions, extracardiac malformations, and extracardiac dysfunctions. Each diagnostic category was allocated a severity weight predicated on established fetal and neonatal mortality risk literature. The evaluation of placental thickness was regarded not merely as a persistent variable but also categorized into three distinct classifications: thin (≤40 mm), intermediate (41–69 mm), and thick (≥70 mm). The examination of correlations was performed utilizing Spearman’s ρ; comparative evaluations among the groups were conducted employing the Kruskal–Wallis and Mann–Whitney U tests. Results: Placental thickness revealed a moderate positive correlation with weighted extracardiac dysfunctions (ρ = 0.36, p < 0.00001), displayed a comparatively weaker yet statistically significant association with cardiac dysfunctions (ρ = 0.13, p = 0.01). Fetuses identified by increased placental thickness (≥70 mm) exhibited notably higher mean scores for both cardiac and extracardiac dysfunctions. Within the cohort exhibiting thick placentas, 25.8% displayed extracardiac dysfunction scores surpassing 0.3, in contrast to only 7.7% within the cohort with thinner placentas. Conclusions: Augmented placental thickness correlates with an elevated cumulative load of fetal dysfunction, especially in the realms of extracardiac and functional cardiac impairments. The measurement of placental thickness may function as a straightforward, supplementary indicator of fetal distress in the third trimester, particularly when utilized alongside targeted imaging modalities.