The correlation of morphological and thrombotic villous arterial lesions with fetal Doppler echocardiographic measurements in the placentas of low-risk term pregnancies.

OBJECTIVE: Few studies have correlated the placental vasculature with fetal cardiac function other than umbilical artery Doppler assessment in low-risk pregnancies. We assessed the contribution of the placental vasculature to fetal echocardiographic parameters using histopathological and morphometric analyses of placental resistance arteries.

STUDY DESIGN: Thirty-four low-risk singleton term pregnancies were assessed, including 24 thrombosis-negative cases (no/minimal gross and histological placental abnormalities) and 10 thrombosis-positive cases (histologically identified chorionic plate/stem vessel thrombosis). Fetal ventricular Doppler inflow velocities (E and A waves) and myocardial systolic (S'), early (E'), and late diastolic (A') tissue Doppler velocities were measured within three days before birth. The myocardial performance index (MPI') was calculated. Morphometric variables of placental stem villi arterioles (external diameter 10-150 μm) were examined, including the mean arteriolar density, total cross-sectional lumen area, and wall area/total vessel area (WA/TVA) ratio.

RESULTS: The thrombosis-positive group had a higher umbilical artery pulsatility index and a lower tricuspid E'/A' ratio compared to the thrombosis-negative group. The WA/TVA ratio of stem villi arterioles was negatively correlated with tricuspid E, A, and S' velocities as well as the E/E' ratio (n = 34). The tricuspid MPI' was positively correlated with the total cross-sectional lumen area of stem villi arterioles (n = 34).

CONCLUSION: We conclude that changes in several fetal echocardiographic parameters are associated with placental vascular histopathological and morphological characteristics in a low-risk population. Further studies are needed to assess whether fetal echocardiographic assessment is a promising prenatal predictor of placental vascular histopathological and morphological characteristics in the general population.